**1.1 Dog populations**

Humans and dogs share a long history and were probably associated with European early-modern humans [1], coexisting indoors and outdoors and colonising new environments, often in cooperation [2]. From ancient times dogs have been used by humans as tools for different purposes, such as hunting, gathering food, caring for livestock, protection, and more recently as detectors of explosives and drugs, as companion animals, or as assistants for people with various types of disease or disability [3–5]. Therefore, their coexistence has been wide-ranging, and has generated numerous opportunities for around 260 zoonotic diseases to emerge between dogs and humans [2, 6].

behaviour of humans that exposes them to infective sources [29, 30]. It has been observed that free-roaming dogs are more exposed and prone to acquiring parasites [24, 31–33]. In Chile, rural dogs are associated with agricultural and livestock activities. They are unsupervised, have freedom to roam and are given limited veterinary care [34]. In Argentina, parasite richness and prevalence are positively associated with free-roaming animals, and only a small proportion of dogs (17%) is subjected to some degree of movement restriction [20]. In the cities of Argentinian Patagonia, another important factor that promotes infection by zoonotic parasites, mainly cystic echinococcosis, is the domestic slaughter of small ruminants for human consumption. This practice occurs frequently in rural areas and the peripheral low-income neighbourhoods of cities, where dogs are fed with the raw offal of sheep and goats [35, 36]. The vast majority of parasites registered in South America

*The State of Knowledge on Intestinal Helminths in Free-Roaming Dogs in Southern…*

*DOI: http://dx.doi.org/10.5772/intechopen.96125*

are cosmopolitan zoonotic parasites transmitted through dog faeces, such as *Toxocara canis*, *Ancylostoma caninum*,*Toxascaris leonina*, *Echinococcus* spp., and *Dipylidium caninum*, which are common parasites in dogs worldwide [12]. Zoonotic parasitic infections in dogs are a public health issue not only in developing countries but also in developed nations, such as in the USA and European countries [37, 38]. Other parasites like *Trichuris vulpis* are distributed worldwide, but are rarely trans-

mitted to humans [39]. Some human parasites like *Ascaris lumbricoide*s and *Strongyloides stercoralis* are occasionally reported in dogs [40, 41]. Therefore, worldwide, dogs may harbour zoonotic parasites that affect the health and

sanitary practices, insufficient hygiene and problems with unconfined and untreated dogs [42]. Pet diseases may pose risks to human health but are rarely included in surveillance systems. Although pet-borne infections have become increasingly relevant to human health, systematic notification of these infections is not currently conducted, except for rabies and Echinococcosis in some countries

[22, 43].

part of public health organisations [44].

(Argentina-Chile-Uruguay).

**2. Materials and methods**

**2.1 Search approach**

Uruguay".

**47**

wellbeing of humans, their distribution being linked to poverty, poor knowledge of

Southern South America is a region with varied geography and climate and marked altitudinal and latitudinal differences; for example, plains (Pampas in Argentina and Uruguay), arid plateaus (Patagonia), forests (Patagonia and northeastern Argentina), and mountains of high altitude between Argentina and Chile (the Andes). The climate ranges from humid tropical in northern Argentina and Uruguay, arid in northern Chile, to humid cold in the south of Argentina and Chile. This climatic variety favours the distribution and occurrence of different parasites. On the other hand, the socio-economic condition of a large part of the population is characterised by poverty and a low-income economy. This scenario is accompanied by a lack of parasitological studies, surveillance and zoonosis control plans on the

The objective of this work is to describe, through bibliographic analysis, the occurrence, prevalence, species richness, and distribution of intestinal helminth parasites found in dog faeces in urban and rural areas of southern South America

Three databases (PubMed, Google Scholar and Scopus) were searched for studies published between 2000 and 2020. The search terms were "dog AND parasite AND Argentina"; "dog AND parasite AND Chile"; and "dog AND parasite AND

There are almost one billion dogs worldwide [7], but the relationship between the numbers of people and dogs varies according to the geographic area and socioeconomic conditions of each country or region [8]. In developed countries the human to dog ratio varies from 6 to 10:1 according to the World Health Organisation [9]; in Italy the human:dog ratio is 9:1 [10], and in the United States it is 3.6:1 [11]. The dog population in South America is very large, around 87.6 million. In Brazil in particular there are 44.9 million children aged under 14 years, and an estimated total of 52.2 million dogs, which means there are more dogs than children [12]. In Argentina, a survey carried out for food companies determined that there are approximately 9 million dogs, and that 78% of households have a dog, whose function is mainly exclusively companionship [13]. The situation in Chile is similar, where the dog population is around 3.5 million and 64% of households have at least one [14], while in Uruguay the dog population is 1.75 million and 72% of households own a dog [15].

To encourage responsible ownership of this large number of dogs, it was necessary to enact laws indicating what responsible dog care implies (Argentina: Decree 1088/11; Chile: No. 21.020/17; Uruguay: No. 1189/14). Animal welfare thus imposes obligations on the owner, which include vaccinations, deworming, neutering, adequate food, and keeping pets confined to the household or taking them outside on a lead, thus preventing them from roaming freely. It should be noted that in most localities of these countries these laws are not enforced effectively [16].

#### **1.2 Dog care**

Although national laws have been promulgated several years ago, knowledge of them and the care received by dogs is far from adequate [17–20]. The biggest problem in these countries is that dogs are allowed to roam freely in public areas, and this is associated with education, socio-economic level, the idiosyncrasy and customs of each country, the role the dog plays within the family, and the low importance that people give to how their dog can affect other people or animals [21]. In addition, allowing dogs to roam freely is strongly correlated with other aspects of dog care, such as a lack of appropriate vaccination and deworming treatment [21]. The care given to dogs that roam freely is poorer than for dogs which are confined, and they are rarely taken to the vet due to the high cost that this represents [22]. In Chile, the average cost spent per pet for annual veterinary checkups, diagnoses, vaccines and treatment is US\$ 330 [4], while in Argentina this cost is around US\$ 100 annually (personal observation). The percentage of vaccinated dogs is low, even when there is a possibility of rabies contagion [14, 23], and the frequency of deworming is in most cases inadequate considering that dogs can roam freely on public roads, becoming reinfected [23–25]. The percentage of animals that are neutered is also insufficient, despite the national or local neutering programs run in the three countries [21, 26, 27]. Neutered animals represent less than half the dog population [21, 23, 28] and the majority are older than 3 years; in many cases dogs are allowed to have at least one litter of offspring [23].

#### **1.3 Dogs, parasites and diseases**

One Health is recognised as a valuable paradigm for global health management, and seeks the integration of human and animal health. The risk of transmission of a zoonotic disease from dogs to humans is related to the abundance of infectious forms in the environment, climatic conditions, whether dogs roam freely, and the

*The State of Knowledge on Intestinal Helminths in Free-Roaming Dogs in Southern… DOI: http://dx.doi.org/10.5772/intechopen.96125*

behaviour of humans that exposes them to infective sources [29, 30]. It has been observed that free-roaming dogs are more exposed and prone to acquiring parasites [24, 31–33]. In Chile, rural dogs are associated with agricultural and livestock activities. They are unsupervised, have freedom to roam and are given limited veterinary care [34]. In Argentina, parasite richness and prevalence are positively associated with free-roaming animals, and only a small proportion of dogs (17%) is subjected to some degree of movement restriction [20]. In the cities of Argentinian Patagonia, another important factor that promotes infection by zoonotic parasites, mainly cystic echinococcosis, is the domestic slaughter of small ruminants for human consumption. This practice occurs frequently in rural areas and the peripheral low-income neighbourhoods of cities, where dogs are fed with the raw offal of sheep and goats [35, 36]. The vast majority of parasites registered in South America are cosmopolitan zoonotic parasites transmitted through dog faeces, such as *Toxocara canis*, *Ancylostoma caninum*,*Toxascaris leonina*, *Echinococcus* spp., and *Dipylidium caninum*, which are common parasites in dogs worldwide [12]. Zoonotic parasitic infections in dogs are a public health issue not only in developing countries but also in developed nations, such as in the USA and European countries [37, 38]. Other parasites like *Trichuris vulpis* are distributed worldwide, but are rarely transmitted to humans [39]. Some human parasites like *Ascaris lumbricoide*s and *Strongyloides stercoralis* are occasionally reported in dogs [40, 41]. Therefore, worldwide, dogs may harbour zoonotic parasites that affect the health and wellbeing of humans, their distribution being linked to poverty, poor knowledge of sanitary practices, insufficient hygiene and problems with unconfined and untreated dogs [42]. Pet diseases may pose risks to human health but are rarely included in surveillance systems. Although pet-borne infections have become increasingly relevant to human health, systematic notification of these infections is not currently conducted, except for rabies and Echinococcosis in some countries [22, 43].

Southern South America is a region with varied geography and climate and marked altitudinal and latitudinal differences; for example, plains (Pampas in Argentina and Uruguay), arid plateaus (Patagonia), forests (Patagonia and northeastern Argentina), and mountains of high altitude between Argentina and Chile (the Andes). The climate ranges from humid tropical in northern Argentina and Uruguay, arid in northern Chile, to humid cold in the south of Argentina and Chile. This climatic variety favours the distribution and occurrence of different parasites. On the other hand, the socio-economic condition of a large part of the population is characterised by poverty and a low-income economy. This scenario is accompanied by a lack of parasitological studies, surveillance and zoonosis control plans on the part of public health organisations [44].

The objective of this work is to describe, through bibliographic analysis, the occurrence, prevalence, species richness, and distribution of intestinal helminth parasites found in dog faeces in urban and rural areas of southern South America (Argentina-Chile-Uruguay).

#### **2. Materials and methods**

#### **2.1 Search approach**

Three databases (PubMed, Google Scholar and Scopus) were searched for studies published between 2000 and 2020. The search terms were "dog AND parasite AND Argentina"; "dog AND parasite AND Chile"; and "dog AND parasite AND Uruguay".

has generated numerous opportunities for around 260 zoonotic diseases to emerge

There are almost one billion dogs worldwide [7], but the relationship between

To encourage responsible ownership of this large number of dogs, it was necessary to enact laws indicating what responsible dog care implies (Argentina: Decree 1088/11; Chile: No. 21.020/17; Uruguay: No. 1189/14). Animal welfare thus imposes obligations on the owner, which include vaccinations, deworming, neutering, adequate food, and keeping pets confined to the household or taking them outside on a lead, thus preventing them from roaming freely. It should be noted that in most

Although national laws have been promulgated several years ago, knowledge of

One Health is recognised as a valuable paradigm for global health management, and seeks the integration of human and animal health. The risk of transmission of a zoonotic disease from dogs to humans is related to the abundance of infectious forms in the environment, climatic conditions, whether dogs roam freely, and the

them and the care received by dogs is far from adequate [17–20]. The biggest problem in these countries is that dogs are allowed to roam freely in public areas, and this is associated with education, socio-economic level, the idiosyncrasy and customs of each country, the role the dog plays within the family, and the low importance that people give to how their dog can affect other people or animals [21]. In addition, allowing dogs to roam freely is strongly correlated with other aspects of dog care, such as a lack of appropriate vaccination and deworming treatment [21]. The care given to dogs that roam freely is poorer than for dogs which are confined, and they are rarely taken to the vet due to the high cost that this represents [22]. In Chile, the average cost spent per pet for annual veterinary checkups, diagnoses, vaccines and treatment is US\$ 330 [4], while in Argentina this cost is around US\$ 100 annually (personal observation). The percentage of vaccinated dogs is low, even when there is a possibility of rabies contagion [14, 23], and the frequency of deworming is in most cases inadequate considering that dogs can roam freely on public roads, becoming reinfected [23–25]. The percentage of animals that are neutered is also insufficient, despite the national or local neutering programs run in the three countries [21, 26, 27]. Neutered animals represent less than half the dog population [21, 23, 28] and the majority are older than 3 years; in many cases

localities of these countries these laws are not enforced effectively [16].

dogs are allowed to have at least one litter of offspring [23].

**1.3 Dogs, parasites and diseases**

**46**

the numbers of people and dogs varies according to the geographic area and socioeconomic conditions of each country or region [8]. In developed countries the human to dog ratio varies from 6 to 10:1 according to the World Health Organisation [9]; in Italy the human:dog ratio is 9:1 [10], and in the United States it is 3.6:1 [11]. The dog population in South America is very large, around 87.6 million. In Brazil in particular there are 44.9 million children aged under 14 years, and an estimated total of 52.2 million dogs, which means there are more dogs than children [12]. In Argentina, a survey carried out for food companies determined that there are approximately 9 million dogs, and that 78% of households have a dog, whose function is mainly exclusively companionship [13]. The situation in Chile is similar, where the dog population is around 3.5 million and 64% of households have at least one [14], while in Uruguay the dog population is 1.75 million and 72% of households

between dogs and humans [2, 6].

*Canine Genetics, Health and Medicine*

own a dog [15].

**1.2 Dog care**

The Google Scholar search in particular returned a large number of results, of which the first 700 titles were read (and in some cases the abstract); however, it was observed that after the first 200 no results were found that met the search requirements.

#### **2.2 Paper assortment**

The studies to be included were identified independently by two reviewers, and were confirmed by a third reviewer following standardised methodology [45]. The studies included met the following criteria: (1) full text articles available online; (2) published between 2000 and 2020; (3) peer-reviewed, original papers published either in English or Spanish; (4) cross-sectional studies that assessed the prevalence of any intestinal helminth parasite of dogs in Argentina, Chile or Uruguay; (5) studies that detected parasite infection in faeces using at least one parasitological, serological and/or molecular method; (6) studies that reported sample sizes, and the prevalence of each parasite species. Reviews and case reports were excluded. The following data were extracted from each article: authors, publication year, country, localities (coordinates), type of locality (rural/urban), sample size, detection method, prevalence of each parasite, number of parasite species.

#### **2.3 Parasite distribution**

The distribution maps were constructed using the Free and Open Source Geographic Information System (QGis system). The coordinates for the site locations were taken from the selected works or were completed using Google Earth. The prevalence values shown on the maps were obtained from the studies included in the bibliographic review. The map of South America was obtained from shape files from *Instituto Geográfico Nacional* [46].

#### **2.4 Statistical analysis**

Spearman's rank Correlation Tests were performed to analyse the relation between richness, with sample size and latitude. All sites with richness = 1 were excluded, since they searched for only one parasite.

#### **3. Results**

From the search in the 3 databases, 29,450 scientific items were found. Of these, 24,517 belong to the period between 2000 and 2020. After analysing the titles and abstracts, 24,298 articles were excluded because they did not comply with the objectives or inclusion criteria, did not include helminths, did not correspond to the countries under study, or were not cross-sectional studies. A total of 219 articles were evaluated for eligibility. After removing the duplicates, 67 were included in the final analysis (**Table 1**), and the full texts of these relevant articles were reviewed in depth. Forty-eight corresponded to Argentina, 17 to Chile, and 2 to Uruguay (**Figure 1**). The data come from analysis of 32,300 dog faeces collected in urban or rural sites of the 3 countries. Sample sizes in the different studies ranged from 4 to 2,417, except for Uruguay where 5,356 faeces were analysed for the National Echinococcosis Control Programs, without considering the presence of other parasites (**Table 1**).

The number of copro-parasitological techniques used in each study varied between 1 and 3, with a total of 15 different methods (**Table 1**). The most

**Autor**

**49**

Acosta Jamett

2010 Chile Tangue

30°20'S,

120

ELISA

71°34'W

 30°11'S,

81

ELISA

1

urban 0

71°25'W

29°57'S,

128

ELISA

1

urban 1

15

27

71°20'W

 31°100S,

52

CoproElisa

1

urban 1

71°030

 37°56'S,

400

Willis Flotation

1

urban 3

62.8

13.9 46.75 22.22 62.96

*The State of Knowledge on Intestinal Helminths in Free-Roaming Dogs in Southern…*

14.17 46.67

23.0

57°35'W

 38°000 S,

125

Flotation, sedimentation of Willis

 1

urban 4

62.96 24.07

2.56

57°330

 38°000 S,

288

Flotation, sedimentation of Willis

 1 2

urban 1

urban 3

65.83

57°330

34°510 S,

217 Formol 10%

 Sedimentation of Teleman and Flotation

of Sheater

57°540

41°10'S,

1780

coproElisa Echinococcus

1 rural

1

1

71°18'W

41°580S,

CoproElisa

1 rural

71°320

41°020 S,

CoproElisa

1 rural

1

1

1

1

70°160

39°560S,

CoproElisa

1 rural

1

68°200

 41°180S,

CoproElisa

1 rural

1

69°350

 41°150 S,

CoproElisa

1 rural

68°420

 40°500 S,

CoproElisa

1 rural

1

1

1

1

68°050

41°510 S,

CoproElisa

1 rural

1

70°540

41°070S,

CoproElisa

1 rural

1

70°430

W

W

W

W

W

W

W

W

W

W

W

W

et al. [47] Acosta Jamett

2010 Chile Guanaqueros

> et al. [47]

Acosta Jamett

2010 Chile Coquimbo

> et al. [47]

Acosta Jamett

2014 Chile Combarbalá

> et al. [48]

Andresiuk

2007 Argentina Mar del Plata

> et al. [49]

Andresiuk

2003 Argentina Mar del Plata

> et al. [50]

Andresiuk

2004 Argentina Mar del Plata

> et al. [29]

Archelli et al.

2018 Argentina Ensenada

[51]

Arezo et al .

2020 Argentina Bariloche

[36]

Arezo et al .

2020 Argentina El Bolson

[36]

Arezo et al.

2020 Argentina Comallo

[36]

Arezo et al.

2020 Argentina El Cuy

[36]

Arezo et al.

2020 Argentina Ing. Jacobacci

[36]

Arezo et al.

2020 Argentina Maquinchao

[36]

Arezo et al.

2020 Argentina Los Menucos

[36]

Arezo et al.

2020 Argentina Ñorquinco

[36]

Arezo et al.

2020 Argentina Pilcaniyeu

[36]

~**no A**

**Country**

**Name Study Locality**

**Coordinates**

**Sample size**

**Fixing method**

**of tection Methods**

**No. Of detection methods**

1 rural

1

10

**RURAL**

**URBAN**

**Richness**

*Ascaris sp.*

*Dipylidium*

*Eucoleus aerophila*

*Eucoleus boehmi*

**Capillaria sp.**

*Spirocerca*

*Taenidae*

*Taenia hydatigena*

*Taenia ovis*

**sp.** *Toxascaris*

**sp.** *Toxocara*

**sp.** *Trichuris*

**sp.** *Physalopetra*

**Trematodes**

*Oncicola canis*

*DOI: http://dx.doi.org/10.5772/intechopen.96125*

*Taenia multiceps*

**Ancylostomids**

**sp.** *Ancylostoma*

*.* **sp** *Uncinaria*

**sp.** *Dibothriocephalus*

**caninum**

**sp.**

**eggs** *Strongyloides*

#### *The State of Knowledge on Intestinal Helminths in Free-Roaming Dogs in Southern… DOI: http://dx.doi.org/10.5772/intechopen.96125*


The Google Scholar search in particular returned a large number of results, of which the first 700 titles were read (and in some cases the abstract); however, it was observed that after the first 200 no results were found that met the search

The studies to be included were identified independently by two reviewers, and were confirmed by a third reviewer following standardised methodology [45]. The studies included met the following criteria: (1) full text articles available online; (2) published between 2000 and 2020; (3) peer-reviewed, original papers published either in English or Spanish; (4) cross-sectional studies that assessed the prevalence of any intestinal helminth parasite of dogs in Argentina, Chile or Uruguay; (5) studies that detected parasite infection in faeces using at least one parasitological, serological and/or molecular method; (6) studies that reported sample sizes, and the prevalence of each parasite species. Reviews and case reports were excluded. The following data were extracted from each article: authors, publication year, country, localities (coordinates), type of locality (rural/urban), sample size, detection

The distribution maps were constructed using the Free and Open Source Geographic Information System (QGis system). The coordinates for the site locations were taken from the selected works or were completed using Google Earth. The prevalence values shown on the maps were obtained from the studies included in the bibliographic review. The map of South America was obtained from shape files

Spearman's rank Correlation Tests were performed to analyse the relation between richness, with sample size and latitude. All sites with richness = 1 were

From the search in the 3 databases, 29,450 scientific items were found. Of these, 24,517 belong to the period between 2000 and 2020. After analysing the titles and abstracts, 24,298 articles were excluded because they did not comply with the objectives or inclusion criteria, did not include helminths, did not correspond to the countries under study, or were not cross-sectional studies. A total of 219 articles were evaluated for eligibility. After removing the duplicates, 67 were included in the final analysis (**Table 1**), and the full texts of these relevant articles were reviewed in depth. Forty-eight corresponded to Argentina, 17 to Chile, and 2 to Uruguay (**Figure 1**). The data come from analysis of 32,300 dog faeces collected in urban or rural sites of the 3 countries. Sample sizes in the different studies ranged from 4 to 2,417, except for Uruguay where 5,356 faeces were analysed for the National Echinococcosis Control Programs, without considering the presence of

The number of copro-parasitological techniques used in each study varied between 1 and 3, with a total of 15 different methods (**Table 1**). The most

method, prevalence of each parasite, number of parasite species.

requirements.

**2.2 Paper assortment**

*Canine Genetics, Health and Medicine*

**2.3 Parasite distribution**

**2.4 Statistical analysis**

other parasites (**Table 1**).

**48**

**3. Results**

from *Instituto Geográfico Nacional* [46].

excluded, since they searched for only one parasite.

#### *Canine Genetics, Health and Medicine*


**Autor**

**51**

Dopchiz et al.

2013 Argentina Lobos, Bs As

 35°100S,

42 Formol 10%,

Sedimetation of Ritchie, Flotation of

3 rural

6

11.9 14.29

19.05 26.19

59°05'W

26°020 S,

85 SAF solution

 Flotation with NaCl and Sedimentation

 2

urban 8

68.2

2.4

1.2

5.9 5.9

14.1 3.5 15.3

*DOI: http://dx.doi.org/10.5772/intechopen.96125*

59°550

41°10'S,

118

Sheater Flotation

1

urban 9

47.0

16.9 0.8 9.3

5.1

 2.5

11.9 12.7 39.0

0.05 12.6 11 14.2 5.4 8.9 14.1

*The State of Knowledge on Intestinal Helminths in Free-Roaming Dogs in Southern…*

6.7 17.9 9.8 10.2

10.2 7.5

16 8 16.7 8.3

8.3

27.3 9.1

71°18'W

34°220 S,

262

Sheater Flotation

1

urban 5

9.1

58°220

34°390 S,

547

Sheater Flotation

1

urban 5

8.9

0.8

58°220

34°500S,

458

Sheater Flotation

1

urban 5

19

58°230

 34°520 S,

134

Sheater Flotation

1

urban 5

21.6

58°280

58°250

34°150 S,

293

Sheater Flotation

1

urban 5

13.6

58°150

34°560 S,

12 Formol 10%

 Sedimentation of Ritchie and Flotation of

2

urban 4

16

16

Willis

57°530

 34°560 S,

5

Sedimentation of Ritchie and Carles

3

urban 4

16.7

16.7

> Barthelemand, and Flotation of Fülleborn

Sedimentation of Ritchie and Carles

3

urban 2

33.3

> Barthelemand, and Flotation of Fülleborn

Sedimentation of Ritchie and Carles

3

urban 4 3 30.0

3.9

15

90.9

9.1

> Barthelemand, and Flotation of Fülleborn

57°570

 34°560 S,

4

57°570

54°530

33°380 S,

40 SAF solution

 Teuscher Methods or Flotation of Willis 2 rural

78°500

w

W

11

W

W

W

W

W

499

Sheater Flotation

1

urban 5

13

W

W

W

W

W

freezado

Sheater and CoproElisa

[58]

Enriquez et al.

2019 Argentina Pampa del Indio,

Chaco

[59]

Flores et al.

2017 Argentina Bariloche

[35]

Fontanarosa

2006 Argentina Lanus

> et al. [60]

Fontanarosa

2006 Argentina Avellaneda

> et al. [60]

Fontanarosa

2006 Argentina Alte Brown

> et al. [60]

Fontanarosa

2006 Argentina E.Echeverria

> et al. [60]

Fontanarosa

2006 Argentina Lomas de Zamora 34°450S,

> et al. [60]

Fontanarosa

2006 Argentina Quilmes

> et al. [60]

Gamboa et al.

2011 Argentina La Plata

[61]

Gamboa et al.

2009 Argentina La Plata Norte

[62]

Gamboa et al.

2009 Argentina La Plata Sur

[62]

Gamboa et al.

2009 Argentina Aristóbulo del Valle 27°050 S,

[62]

Gonzalez

2008 Chile Archipiélago de

> Acuña et al.

> Juan Fernández

> > [63]

Gorman et al.

2006 Chile Santiago de Chile 33°270 S,

70°

582

Flotation zinc sulfate and Sedimentation

2

urban 5 5.3

2.1

2.4 9.1 8.6

> of Teleman modified

5356

CoproElisa 1

3.6

400

W

[31]

Irabedra et al.

2016 Uruguay

[64]

~**no A**

**Country**

**Name Study Locality**

**Coordinates**

**Sample size**

**Fixing method**

**of tection Methods**

**No. Of detection methods**

**RURAL**

**URBAN**

**Richness**

*Ascaris sp.*

*Dipylidium*

*Eucoleus aerophila*

*Eucoleus boehmi*

**Capillaria sp.**

*Spirocerca*

*Taenidae*

*Taenia hydatigena*

*Taenia ovis*

**sp.** *Toxascaris*

**sp.** *Toxocara*

**sp.** *Trichuris*

**sp.** *Physalopetra*

**Trematodes**

*Oncicola canis*

26.19

*Taenia multiceps*

**Ancylostomids**

**sp.** *Ancylostoma*

*.* **sp** *Uncinaria*

**sp.** *Dibothriocephalus*

**caninum**

**sp.**

**eggs** *Strongyloides*

#### *The State of Knowledge on Intestinal Helminths in Free-Roaming Dogs in Southern… DOI: http://dx.doi.org/10.5772/intechopen.96125*


**Autor**

**50**

Arezo et al.

2020 Argentina Ramos Mexia

 40°300 S,

67°170

 40°350S,

CoproElisa

1 rural

1

67°450

 41°360 S,

CoproElisa

1 rural

65°21'W

40°420 S,

CoproElisa

1 rural

1

1

9.3

4.7

12.4 4.7

66°090

37°24'S,

196

Flotation with zinc

1

urban 4

72°31'W

22°060 S,

89

Copro, Elisa and WB

2 1

urban 4

4.5

0.7

13.5 7.3

6.17

urban 1

2.2

65°360

70°

acetate

288 Formol salino Telemann modified, using ethandl

400

W

57°44'W

34°560 S,

78

Sedimentation of Ritchie and Flotation of

2

urban 7

69.2 41.0

1.3

1.3

1.3 21.8 28.2

5.0 1.3

Willis

57°570

54°480S,

80 Formol 5%

 Sedimentation and Flotac

2

urban 7

1.3

2.5 11.7

27.7

14.0

9.5

2.0

10.7

14.8

68°180

23°510S,

222

Copro, Elisa and WB

2

1

65°280

 23°120 S,

18

Copro, Elisa and WB

2

1

65°210

23°340 S,

64

Copro, Elisa and WB

2

1

65°230

22°440 S,

94

Copro, Elisa and WB

2

1

65°530

23°240 S,

50

Copro, Elisa and WB

2

1

66°220

 21°560S,

28

Copro, Elisa and WB

2

1

66°030

22°070 S,

47

Copro, Elisa and WB

2

1

65°270

W

W

W

W

W

W

W

W

W

81

Sedimentation of Teleman modified

 1 rural

1

W

W

W

W

[36]

Arezo et al.

2020 Argentina Sierra Colorada

[36]

Arezo et al.

2020 Argentina Sierra Grande

[36]

Arezo et al .

2020 Argentina Valcheta

[36]

Armstrong

2011 Chile Temuco

> et al. [52]

Casas et al.

2013 Argentina La Quiaca

[53]

Castillo et al.

2000 Chile Santiago de Chile 33°270 S,

[54]

Chiodo et al.

2006 Argentina General Mansilla 35°04'S,

[55]

Cociancic et al.

2017 Argentina La Plata

[56]

Cociancic et al.

2020 Argentina Ushuaia

[32]

De Costas et al.

2014 Argentina Tumbaya

[57]

De Costas et al.

2014 Argentina Humahuaca

[57]

De Costas et al.

2014 Argentina Tilcara

[57]

De Costas et al.

2014 Argentina Cochinoca

[57]

De Costas et al.

2014 Argentina Susques

[57]

De Costas et al.

2014 Argentina Santa Catalina

[57]

De Costas et al.

2014 Argentina Yavi

[57]

~**no A**

**Country**

**Name Study Locality**

**Coordinates**

**Sample size**

**Fixing method**

**of tection Methods**

CoproElisa

**No. Of detection methods**

1 rural

1

1

1

**RURAL**

**URBAN**

**Richness**

*Ascaris sp.*

*Dipylidium*

*Eucoleus aerophila*

*Eucoleus boehmi*

**Capillaria sp.**

*Spirocerca*

*Taenidae*

*Taenia hydatigena*

*Taenia ovis*

**sp.** *Toxascaris*

**sp.** *Toxocara*

**sp.** *Trichuris*

**sp.** *Physalopetra*

**Trematodes**

*Oncicola canis*

*Canine Genetics, Health and Medicine*

*Taenia multiceps*

**Ancylostomids**

**sp.** *Ancylostoma*

*.* **sp** *Uncinaria*

**sp.** *Dibothriocephalus*

**caninum**

**sp.**

**eggs** *Strongyloides*

#### *Canine Genetics, Health and Medicine*


**Autor**

**53**

Lopez et al.

2006 Chile Santiago de Chile 33°270 S,

70°

and formaldehído

972 PAF fenol, alcohol

Burrows Technique

400

W

36°370 S,

223 PAF fenol, alcohol

Burrows Technique

1

urban 9

8.1 0.9

9.9

2.7

 3.1

1.8

 6.3 22.9 8.1

*DOI: http://dx.doi.org/10.5772/intechopen.96125*

72°570

37°28'S,

452 PAF fenol, alcohol

Burrows Technique

2

urban 7

4.2 0.44

2.6

0.44

1.6

 1.3 9.3

72°21'W

36°490S,

64 PAF fenol, alcohol

Burrows Technique

1

urban 5

8.5

29

4.5

6.3

29.7

73°030

 38°000 S,

358

Flotation with NaCl

1

urban 7 urban 3

64.5

18.9 11.5

1.1

0.6 5.9 13.4

7.6 3.1

*The State of Knowledge on Intestinal Helminths in Free-Roaming Dogs in Southern…*

7.0

62.0 12.0

6.0 1.0

5.0

5.0 1.0 5.0 1.0 6.0 3.0 5.0 2.0

4

2

57°330

27°25'S,

900

Flotation of Willis, Sheater and Faust 3

58°52'W

31°440S,

61 Solución salina 5% Concentration methods

1 1 1 1 1 1 1 1

urban 3

9.0

urban 3

8.0

urban 3

4.0

urban 3

2.0

urban 2

5.0

urban 3

5.0

urban 3

14.0

urban 2

67.0

60°310

31°380S,

200 Solución salina 5% Concentration methods

60°420

29°070 S,

15 Solución salina 5% Concentration methods

59°390

29°090 S,

10 Solución salina 5% Concentration methods

59°390

29°530 S,

17 Solución salina 5% Concentration methods

60°160

61°510

31°440S,

24 Solución salina 5% Concentration methods

61°060

31°400S,

54 Solución salina 5% Concentration methods

60°

460

W

18°280 S,

50

Sedimentation and Harada, Mori

2

urban 2

2

70°190

 23°380 S,

50

Sedimentation and Harada, Mori

2

urban 2

70°230

W

W

W

W

12 Solución salina 5% Concentration methods

W

W

W

W

W

W

W

and formaldehído

and formaldehído

W

and formaldehído

[71]

Luzio et al.

2013 Chile Tomé

[72]

Luzio et al.

2015 Chile Santa de los

[73]

Luzio et al.

2017 Chile Concepcion

[74]

Madrid et al.

2008 Argentina Mar del Plata

[75]

Marder et al.

2004 Argentina Ciudad de

Corrientes

[76]

Martin et al.

2008 Argentina Paraná

[77]

Martin et al.

2008 Argentina Santa Fé

[77]

Martin et al.

2008 Argentina Avellaneda (Santa

[77]

Martin et al.

2008 Argentina Reconquista (Santa

[77]

Martin et al.

2008 Argentina Calchaquí (Santa

[77]

Martin et al.

2008 Argentina Hersilia (Santa Fé) 30°000 S,

[77]

Martin et al.

2008 Argentina San Carlos Centro

[77]

Martin et al.

2008 Argentina Santo Tomé (Santa

[77]

Mercado et al.

2004 Chile Arica

[78]

Mercado et al.

2004 Chile Antofagasta

[78]

Fé)

(Santa Fé)

Fé)

Fé)

Fé)

Angeles

~**no A**

**Country**

**Name Study Locality**

**Coordinates**

**Sample size**

**Fixing method**

**of tection Methods**

**No. Of detection methods**

1

urban 7 1.8

2.2

**RURAL**

**URBAN**

**Richness**

*Ascaris sp.*

*Dipylidium*

*Eucoleus aerophila*

*Eucoleus boehmi*

**Capillaria sp.**

*Spirocerca*

*Taenidae*

*Taenia hydatigena*

0.4

 1.4 11.1 8.9

1.2

*Taenia ovis*

**sp.** *Toxascaris*

**sp.** *Toxocara*

**sp.** *Trichuris*

**sp.** *Physalopetra*

**Trematodes**

*Oncicola canis*

*Taenia multiceps*

**Ancylostomids**

**sp.** *Ancylostoma*

*.* **sp** *Uncinaria*

**sp.** *Dibothriocephalus*

**caninum**

**sp.**

**eggs** *Strongyloides*

#### *The State of Knowledge on Intestinal Helminths in Free-Roaming Dogs in Southern… DOI: http://dx.doi.org/10.5772/intechopen.96125*


**Autor**

**52**

Irabedra et al.

2016 Uruguay

[64]

La Sala et al.

2015a Argentina Bahía Blanca

 38°440 S,

475 Formol 10%

 Sedimentation of Ritchie

1

urban 5

21.1

0.6 0.6

2.3 18.1 25.8

21.9

2.3 18.1

*Canine Genetics, Health and Medicine*

62°160

 38°430 S,

475

Direct observation

1

urban 5

22.3

62°160

35°390S,

785

Flotation with ClNa

1

urban 3

45.4

7.1

63°450

35°400S,

1229

Flotation with ClNa and ZnSO4

2

urban 3

45.4

6.4

63°440

41°580S,

68

Copro, Elisa and WB

2 rural

1

11.8

6.1

6.4

5.3

8.3

7.4

12.5

5.4

2.4

4.7

7.2

71°320

39°560S,

81

Copro, Elisa and WB

2 rural

1

68°200

41°510 S,

47

Copro, Elisa and WB

2 rural

1

70°540

41°070S,

19

Copro, Elisa and WB

2 rural

1

70°430

41°020 S,

12

Copro, Elisa and WB

2 rural

1

70°160

69°350

 41°150 S,

16

Copro, Elisa and WB

2 rural

1

68°420

 40°500 S,

37

Copro, Elisa and WB

2 rural

1

68°050

 40°350S,

42

Copro, Elisa and WB

2 rural

1

67°450

40°420 S,

106

Copro, Elisa and WB

2 rural

1

66°090

 41°360 S,

14

Copro, Elisa and WB

2 rural

1

65°21'W

 38°000 S,

46 Formol 10%

 Sediemtation of Ritchie and Flotation of

3

urban 6

71.74 41.3

8.6 17.36

63.04 45.65

> Sheater and coproELISA

57°330

W

W

W

W

W

W

108

Copro, Elisa and WB

2 rural

1

W

W

W

W

W

W

W

W

W

[65]

La Sala et al.

2015b Argentina Bahia Blanca

[66]

Lamberti et al .

2014 Argentina Gra. Pico

[67]

Lamberti et al.

2015 Argentina Gral Pico

[68]

Larrieu et al.

2014 Argentina El Bolsón

[69]

Larrieu et al.

2014 Argentina El Cuy

[69]

Larrieu et al.

2014 Argentina Ñorquinco

[69]

Larrieu et al.

2014 Argentina Pilcaniyeu

[69]

Larrieu et al.

2014 Argentina Comallo

[69]

Larrieu et al.

2014 Argentina Ingeniero Jacobacci 41°180S,

[69]

Larrieu et al.

2014 Argentina Maquinchao

[69]

Larrieu et al.

2014 Argentina Los Menucos

[69]

Larrieu et al.

2014 Argentina Sierra Colorada

[69]

Larrieu et al.

2014 Argentina Valcheta

[69]

Larrieu et al.

2014 Argentina Sierra Grande

[69]

Lavallén et al.

2011 Argentina Gral Pueyrredon

[70]

~**no A**

**Country**

**Name Study Locality**

**Coordinates**

**Sample size**

**Fixing method**

**of tection Methods**

1496

**No. Of detection methods**

CoproElisa

1

7.35

**RURAL**

**URBAN**

**Richness**

*Ascaris sp.*

*Dipylidium*

*Eucoleus aerophila*

*Eucoleus boehmi*

**Capillaria sp.**

*Spirocerca*

*Taenidae*

*Taenia hydatigena*

*Taenia ovis*

**sp.** *Toxascaris*

**sp.** *Toxocara*

**sp.** *Trichuris*

**sp.** *Physalopetra*

**Trematodes**

*Oncicola canis*

*Taenia multiceps*

**Ancylostomids**

**sp.** *Ancylostoma*

*.* **sp** *Uncinaria*

**sp.** *Dibothriocephalus*

**caninum**

**sp.**

**eggs** *Strongyloides*

#### *Canine Genetics, Health and Medicine*


**Autor**

**55**

Milano et al.

2005 Argentina Ciudad de

Corrientes

27°25'S,

34 Formol 10%

 Sedimentation and flotation of Willis 2

58°52'W

27°25'S,

44 Formol 10%

 Sedimentation and flotation of Willis 2

58°52'W

27°25'S,

38 Formol 10%

 Sedimentation and flotation of Willis 2

58°52'W

33°070S,

493 Formol 10%

 Flotation of Willis, and Sheather, and

3

urban 5

30.83

0.61

1.42

Sedimentation

64°200

27°580 S,

28 Formol 10%

 Flotation Sheater and sedimentation of

2 rural

6

4 4

4

7

14

4 4

Ritchie

57°590

57°350

 31°420 S,

79

Necropsy

1

urban 4

38 23

1

8

55°580

31°450 S,


Necropsy

1 rural

6 urban 4

1 30 3.49

4 21.5 12.7

21.5 35.2

23 3

55°580

37°24'S,

102

Flotation and Sedimentation of Teuscher 1

72°36'W

33°020 S,

30 PAF fenol, alcohol

Burrows Technique

1 rural

6 7

5

25.5

4 13

7

4

3

6

8

53.9

30.5

15.6

13

17

17

40 3

71°370

38°000 S,

270 Alcohol

Sedimentation and Flotation of Teuscher 1 rural

73°140

26°350S,

43

CoproElisa

1 rural

1

65°330

26°450S,

22

CoproElisa

1 rural

1

65°340

26°410S,

7

CoproElisa

1 rural

1

65°360

26°410S,

5

CoproElisa

1 rural

1

65°310

26°470S,

9

CoproElisa

1 rural

1

65°330

26°410S,

17

CoproElisa

1 rural

1

65°360

W

W

W

W

W

W

W

W

and formaldehído

W

31.75

W

W

23 Formol 10%

 Flotation Sheater and Sedimentation of

2 rural

3

52

9

9

*The State of Knowledge on Intestinal Helminths in Free-Roaming Dogs in Southern…*

Ritchie

W

W

[79]

Milano et al.

2005 Argentina Ciudad de

Corrientes

[79]

Milano et al.

2005 Argentina Ciudad de

Corrientes

[79]

Motta et al .

2019 Argentina Rio Cuarto

[80]

Natalini et al .

2020 Argentina Parque Nac

[81]

Natalini et al .

2020 Argentina San Nicolás NP 27°590 S,

[81]

Oku et al. [82] 2004 Uruguay Tacuarembo

Oku et al. [82] 2004 Uruguay

Olivares et al.

2014 Chile Temuco

[83]

Opazo et al.

2019 Chile Valparaiso

[84]

Oyarzun et al.

2019 Chile Contulmo

[85]

Parra et al.

2017 Argentina Ancajuli

[86]

Parra et al.

2017 Argentina Anfama

[86]

Parra et al.

2017 Argentina Chaquivil

[86]

Parra et al.

2017 Argentina La Hoyada

[86]

Parra et al.

2017 Argentina Mala Mala

[86]

Parra et al.

2017 Argentina San José de

[86]

Chasquivil

Mburucuya

~**no A**

**Country**

**Name Study Locality**

**Coordinates**

**Sample size**

**Fixing method**

**of tection Methods**

**No. Of detection methods**

**RURAL**

**URBAN**

urban 3 urban 4 urban 4

50.0

2.6

43.2

4.5

38.2

**Richness**

*Ascaris sp.*

*Dipylidium*

*Eucoleus aerophila*

*Eucoleus boehmi*

**Capillaria sp.**

*Spirocerca*

*Taenidae*

*Taenia hydatigena*

*Taenia ovis*

17.6 5.9

6.8

15.8 7.9

*DOI: http://dx.doi.org/10.5772/intechopen.96125*

6.9 9.94

**sp.** *Toxascaris*

**sp.** *Toxocara*

**sp.** *Trichuris*

**sp.** *Physalopetra*

**Trematodes**

*Oncicola canis*

*Taenia multiceps*

**Ancylostomids**

**sp.** *Ancylostoma*

*.* **sp** *Uncinaria*

**sp.** *Dibothriocephalus*

**caninum**

**sp.**

**eggs** *Strongyloides*

#### *The State of Knowledge on Intestinal Helminths in Free-Roaming Dogs in Southern… DOI: http://dx.doi.org/10.5772/intechopen.96125*


**Autor**

**54**

Mercado et al.

2004 Chile Illapel

31°370 S,

50

Sedimentation and Harada, Mori

2

urban 2

7.2

71°100

 33°010S,

27

Sedimentation and Harada, Mori

2

urban 2

71°330

33°020 S,

40

Sedimentation and Harada, Mori

2

urban 2

10

71°370

32°450 S,

44

Sedimentation and Harada, Mori

2

urban 2

70°430

70°

54

Sedimentation and Harada, Mori

2

urban 2

400

W

34°090 S,

27

Sedimentation and Harada, Mori

2

urban 2

70°440

 34°350S,

50

Sedimentation and Harada, Mori

2

urban 2

24

70°590

36°490S,

49

Sedimentation and Harada, Mori

2

urban 2

8.2

73°030

38°440 S,

50

Sedimentation and Harada, Mori

2

urban 2

40

72°350

39°480 S,

50

Sedimentation and Harada, Mori

2

urban 2

20

73°140

 53°090 S,

54

Sedimentation and Harada, Mori

2

urban 2 urban 4 urban 4 urban 4 urban 3 urban 4 urban 3

48.2

45.0

2.5

50.0

35.0

12.5

35.0

2.5

32.8

1.6

70°540

27°25'S,

61 Formol 10%

 Sedimentation and flotation of Willis 2

58°52'W

27°25'S,

40 Formol 10%

 Sedimentation and flotation of Willis 2

58°52'W

27°25'S,

40 Formol 10%

 Sedimentation and flotation of Willis 2

58°52'W

27°25'S,

32 Formol 10%

 Sedimentation and flotation of Willis 2

58°52'W

27°25'S,

40 Formol 10%

 Sedimentation and flotation of Willis 2

58°52'W

27°25'S,

33 Formol 10%

 Sedimentation and flotation of Willis 2

58°52'W

W

W

W

W

W

W

W

W

W

W

[78]

Mercado et al.

2004 Chile Viña del Mar

[78]

Mercado et al.

2004 Chile Valparaiso

[78]

Mercado et al.

2004 Chile San Felipe

[78]

Mercado et al.

2004 Chile Santiago de Chile 33°270 S,

[78]

Mercado et al.

2004 Chile Rancagua

[78]

Mercado et al.

2004 Chile San Fernando

[78]

Mercado et al.

2004 Chile Concepcion

[78]

Mercado et al.

2004 Chile Temuco

[78]

Mercado et al.

2004 Chile Valdivia

[78]

Mercado et al.

2004 Chile Punta Arenas

[78]

Milano et al.

2005 Argentina Ciudad de

Corrientes

[79]

Milano et al.

2005 Argentina Ciudad de

Corrientes

[79]

Milano et al.

2005 Argentina Ciudad de

Corrientes

[79]

Milano et al.

2005 Argentina Ciudad de

Corrientes

[79]

Milano et al.

2005 Argentina Ciudad de

Corrientes

[79]

Milano et al.

2005 Argentina Ciudad de

Corrientes

[79]

~**no A**

**Country**

**Name Study Locality**

**Coordinates**

**Sample size**

**Fixing method**

**of tection Methods**

**No. Of detection methods**

**RURAL**

**URBAN**

**Richness**

*Ascaris sp.*

*Dipylidium*

*Eucoleus aerophila*

*Eucoleus boehmi*

**Capillaria sp.**

*Spirocerca*

*Taenidae*

*Taenia hydatigena*

*Taenia ovis*

10

*Canine Genetics, Health and Medicine*

12.5

6.8

1.9

7.4

8

6.1

4

4

1.9

26.3 3.3 17.5 2.5 12.5 10.0

15.6 9.4 20.0 2.5 6.0 3.0

**sp.** *Toxascaris*

**sp.** *Toxocara*

**sp.** *Trichuris*

**sp.** *Physalopetra*

**Trematodes**

*Oncicola canis*

*Taenia multiceps*

**Ancylostomids**

**sp.** *Ancylostoma*

*.* **sp** *Uncinaria*

**sp.** *Dibothriocephalus*

**caninum**

**sp.**

**eggs** *Strongyloides*

#### *Canine Genetics, Health and Medicine*


**Autor**

**57**

Soriano et al.

2010 Argentina Neuquén urbano

[101]

Souto et al.

2016 Argentina El Chalía (Chubut) 45°410 S, 70°590W

23°15'S,

106

Directo, Flotation of Willis and

3

urban 4

69.8

centrifugation

Sedimentation

1

urban 1

1.8

63°20'W

39°380 S,

109 PAF fenol, alcohol

72°200W

 39°500 S,

22 PAF fenol, alcohol

Sedimentation

1 3

 1

15.4

*The State of Knowledge on Intestinal Helminths in Free-Roaming Dogs in Southern*

15.6

urban 1

4.5

72°040W

39°48'S,

78 Formol salino Sedimentation of Telemann modified,

73°14'W

Flotation Sulphate Zinc, método

cuantitativo

y formaldehído

y formaldehído

22 Formol 10%

 Sedimentation of Teleman, Flotation of

3 rural

2

13.6

9.1

*DOI: http://dx.doi.org/10.5772/intechopen.96125*

1.9

17.2 7.5

Willis and copro, Elisa

[102]

Taranto et al.

2000 Argentina Fortín Dragones y Misión Chaqueña

[103]

Torres et al.

2004 Chile Panguipulli

[104]

Torres et al.

2004 Chile Choshuenco

[104]

Vargas et al.

2016 Chile Niebla

[105]

Vargas et al.

2016 Chile Valdivia

39°48'S,

77 Formol salino Sedimentation of Telemann modified,

73°14'W

Flotation Sulphate Zinc, método

3

urban 1

cuantitativo

[105]

Winter et al.

2018 Argentina Viedma

40°48'S,

531

Flotation de Sheater

1

urban 6

33.8

2.2

0.7

2.9 22.8 40.4

62°59'W

57°43'W

45°S, 68°

31 Formol 5%

 Flotation of Willis

1

urban 2

9.7 3.3

33.3

10.3

3.3

W

43°150 S,

30 Formol 5%

 Flotation of Willis

1

urban 3

3.3

65°180W

 42°460 S,

29 Formol 5%

 Flotation of Willis

1

urban 1

65°020W

45°360 S,

29 Formol 5%

 Flotation of Willis

1

urban 3

6.9

6.9 3.4 6.9

20.0

13.8

*…*

24.1

69°050

42°540 S,

29 Formol 5%

 Flotation of Willis

1

urban 3

6.9

71°19'W

42°090 S,

30 Formol 5%

 Flotation of Willis

1

urban 3

16.7

71°380W

16 Formol

Sedimentation of Ritchie and Flotation of

2

urban 4

62.5 37.5

Willis

[106]

Zonta et al

2019 Argentina Clorinda (Formosa) 25°17'S,

[107]

Zunino et al.

2000 Argentina Comodoro

Rivadavia

[108]

Zunino et al.

2000 Argentina Trelew

[108]

Zunino et al.

2000 Argentina Puerto Madryn

[108]

Zunino et al.

2000 Argentina Sarmiento

[108]

Zunino et al.

2000 Argentina Esquel

[108]

Zunino et al.

2000 Argentina Lago Puelo

[108]

**Table 1.**

*Data extracted from the 67 articles selected for analysis.*

(neuquen y chos

37°230 S,

646 Formol 5%

 Flotation and Sedimentation

70°170W

malal

~**no A**

**Country**

**Name Study Locality**

**Coordinates**

**Sample size**

**Fixing method**

**of tection Methods**

**No. Of detection methods**

2

urban 6

0.93

**RURAL**

**URBAN**

**Richness**

*Ascaris sp.*

*Dipylidium*

*Eucoleus aerophila*

*Eucoleus boehmi*

**Capillaria sp.**

*Spirocerca*

*Taenidae*

*Taenia hydatigena*

*Taenia ovis*

**sp.** *Toxascaris*

**sp.** *Toxocara*

**sp.** *Trichuris*

**sp.** *Physalopetra*

**Trematodes**

*Oncicola canis*

*Taenia multiceps*

> 0.31

> 2.17

16.1 15.63

**Ancylostomids**

**sp.** *Ancylostoma .* **sp** *Uncinaria*

**sp.** *Dibothriocephalus*

**caninum**

**sp.**

**eggs** *Strongyloides*

#### *The State of Knowledge on Intestinal Helminths in Free-Roaming Dogs in Southern… DOI: http://dx.doi.org/10.5772/intechopen.96125*


 *the 67 articles selected for analysis.*

**Autor**

**56**

Perez et al.

2006 Argentina Rio Negro

40°480 S,

416

Copro, Elisa and WB

63°

000

W

37°2'S,

83

Flotation of Sheater

1

urban 1 41

72°24'W

[87]

Quilodrán-González et al.

2018 Chile Cabrero

[88]

Quilodrán-González et al.

2018 Chile Cabrero

37°2'S,

10

Flotation of Sheater

1 rural

2 60

72°24'W

[88]

Radman et al.

2006 Argentina Capital Federal

 34°34S,

125

Flotation of Fülleborn

1

urban 1

58°31W

25°350S,

405 Formol 10%

 Flotation of Sheater and Sedimentation of

2 rural

1

0.49

Telemann

54°340

25°350S,

530 Formol 10%

 Direct with lugol, Flotation of Sheater

3

urban 8

0.9 0.9 1.3

55.6

 0.4

3.9 13.4 12.1

> and Sedimentation of Teleman

54°340

 38°000 S,

171

Flotation and Sedimentation

2

urban 6

67.8 42.4

1.5

5.6

6.8 52.2

14.0

13.0 32.0

57°330

41°080 S,

118 Freezado

Flotation of Sheater and Sedimentation of

2

urban 1

16.9

Telemann

71°270

 34°34S,

31 Formol 5%

 Sedimentation of Teleman

1

urban 1

58°31W

 34°34S,

2417 Formol 5%

 Sedimentation of Teleman

1

urban 4

33.5

0.7

58°31'W

 34°34'S,

421 Formol 5%

 Flotation of Willis

1

urban 7 urban 4

20.5

26.0

0.6

0.9

 0.6 0.9

1.8 3.6

0.2 1.7 4.0

58°31'W

 34°370S,

112

Centrifugation and Flotation of Sheater 2

58°250

45°S, 68°

481 Formol 5%

 Sedimentation de Teleman and Flotation

2

urban 6

1.0

0.2

0.2

2.6 3.6

17.9

de Willis

W

W

W

W

W

W

[89]

Rivero et al.

2015 Argentina Puerto Iguazú y

alrededres

[90]

Rivero et al.

2017 Argentina Puerto Iguazú y

alrededres

[91]

Rodriguez

2005 Argentina Mar del Plata

> et al. [92]

Roth et al. [93] 2018 Argentina Bariloche

Rubel et al.

2003 Argentina Capital Federal

[94]

Rubel et al.

2005 Argentina Capital Federal

[95]

Rubel et al.

2010 Argentina Capital Federal

[96]

Rubel et al.

2019 Argentina Buenos Aires

[97]

Sánchez et al.

2003 Argentina Comodoro

Rivadavia y Rada

Tilly

[98]

Sánchez

2003 Argentina Comodoro

> Thevenet et al.

Rivadavia

45°S, 68°

163 Formol 5%

 Sedimentation of Teleman and Flotation

2

urban 6

0.8

0.3

1.6 1.4

8.8

of Willis

W

[99]

Semenas et al.

2014 Argentina Bariloche

41°10'S,

54

Sedimentation of Teleman and Flotation

2

urban 10

1.8 3.7

12.8

3.6

1.8

 12.8

 7.3 17.87

0.84 16.4 1.3

0.3

1.8 11.0 29.3

> of Sheater

71°18'W

69°460

W

1298 Formol 5%

 Flotation and Sedimentation

2 rural

8

0.15

0.15 0.15

[100]

Soriano et al.

2010 Argentina Neuquen rural 38°140S,

[101]

~**no A**

**Country**

**Name Study Locality**

**Coordinates**

**Sample size**

**Fixing method**

**of tection Methods**

**No. Of detection methods**

2

2

4.6

14.9

4.8

4.8 13.3

*Canine Genetics, Health and Medicine*

10

51.2

**RURAL**

**URBAN**

**Richness**

*Ascaris sp.*

*Dipylidium*

*Eucoleus aerophila*

*Eucoleus boehmi*

**Capillaria sp.**

*Spirocerca*

*Taenidae*

*Taenia hydatigena*

*Taenia ovis*

**sp.** *Toxascaris*

**sp.** *Toxocara*

**sp.** *Trichuris*

**sp.** *Physalopetra*

**Trematodes**

*Oncicola canis*

*Taenia multiceps*

**Ancylostomids**

**sp.** *Ancylostoma*

*.* **sp** *Uncinaria*

**sp.** *Dibothriocephalus*

**caninum**

**sp.**

**eggs** *Strongyloides*

#### **Figure 1.**

*Flow diagram of epidemiologic studies on dog parasites for the systematic review.*

commonly used techniques were Willis flotation (20 reports), Sheater flotation (15 reports) and Telemann sedimentation (14 reports). In Uruguay only two methods were used: necropsy of stray dogs and coproELISA for *Echinococcus* sp., whereas in Argentina and Chile the techniques in common were Faust, Sheater, Telemann, Willis, and coproELISA for *Echinococcus* sp. Chilean researchers also used a modification of Faust (Teuscher), Burrows, and Harada-Mori for larvae. Other methods used only in Argentina were Füllerborn, Mini Flotac; Ritchie, Carles Barthelemy, direct observation with lugol; and Western Blot and PCR molecular techniques for *E. granulosus*.

A total of 22 parasite taxa was recorded (**Table 3**): 1 trematode (Trematoda sp.), 7 cestodes (*Dibothriocephalus* sp., *Dipylidium caninum*, *Echinococcus* sp., Taenidae, *Taenia multiceps*,*Taenia hydatigena*,*Taenia ovis*), 13 nematodes (*Trichuris vulpis,*

Ancylostomatidae sp., *Ancylostoma* sp., *Uncinaria* sp., *Ascaris* sp.,*Toxascaris leonina*, *Toxocara canis, Spirocerca* sp*.*, and *Physaloptera* sp.), and 1 acanthocephalan species (*Oncicola canis*). In Argentina the presence of *Ancylostoma* was recorded up to genus level, whereas in Chile they were recorded only as Ancylostomatidae sp., so while it is likely that there are some shared species, this cannot be established from the records analysed. The distribution of the species is presented in **Figures 3**–**5**, which show that most of the parasitic records are located in the central zone of Chile, while

*Eucoleus aerophila*, *Eucoleus boehmi*, *Capillaria* sp., *Strongyloides* sp.,

*The State of Knowledge on Intestinal Helminths in Free-Roaming Dogs in Southern…*

*DOI: http://dx.doi.org/10.5772/intechopen.96125*

*Distribution of collection sites and species richness in each site.*

**Figure 2.**

**59**

More than 140 sites were analysed in Chile and Argentina (**Figure 2**, **Table 1**); however, the number of sites analysed in Uruguay could not be determined as this information is not given in the 2 selected studies. In Argentina and Chile, a total of 104 urban sites and 43 rural areas were considered (**Table 2**).

*The State of Knowledge on Intestinal Helminths in Free-Roaming Dogs in Southern… DOI: http://dx.doi.org/10.5772/intechopen.96125*

**Figure 2.** *Distribution of collection sites and species richness in each site.*

A total of 22 parasite taxa was recorded (**Table 3**): 1 trematode (Trematoda sp.), 7 cestodes (*Dibothriocephalus* sp., *Dipylidium caninum*, *Echinococcus* sp., Taenidae, *Taenia multiceps*,*Taenia hydatigena*,*Taenia ovis*), 13 nematodes (*Trichuris vulpis, Eucoleus aerophila*, *Eucoleus boehmi*, *Capillaria* sp., *Strongyloides* sp., Ancylostomatidae sp., *Ancylostoma* sp., *Uncinaria* sp., *Ascaris* sp.,*Toxascaris leonina*, *Toxocara canis, Spirocerca* sp*.*, and *Physaloptera* sp.), and 1 acanthocephalan species (*Oncicola canis*). In Argentina the presence of *Ancylostoma* was recorded up to genus level, whereas in Chile they were recorded only as Ancylostomatidae sp., so while it is likely that there are some shared species, this cannot be established from the records analysed. The distribution of the species is presented in **Figures 3**–**5**, which show that most of the parasitic records are located in the central zone of Chile, while

commonly used techniques were Willis flotation (20 reports), Sheater flotation (15 reports) and Telemann sedimentation (14 reports). In Uruguay only two methods were used: necropsy of stray dogs and coproELISA for *Echinococcus* sp., whereas in Argentina and Chile the techniques in common were Faust, Sheater, Telemann, Willis, and coproELISA for *Echinococcus* sp. Chilean researchers also used a modification of Faust (Teuscher), Burrows, and Harada-Mori for larvae. Other methods used only in Argentina were Füllerborn, Mini Flotac; Ritchie, Carles Barthelemy, direct observation with lugol; and Western Blot and PCR molecular

More than 140 sites were analysed in Chile and Argentina (**Figure 2**, **Table 1**); however, the number of sites analysed in Uruguay could not be determined as this information is not given in the 2 selected studies. In Argentina and Chile, a total of

104 urban sites and 43 rural areas were considered (**Table 2**).

*Flow diagram of epidemiologic studies on dog parasites for the systematic review.*

techniques for *E. granulosus*.

*Canine Genetics, Health and Medicine*

**Figure 1.**

**58**


#### **Table 2.**

*Summary of studies: Total number of reports analysed for the three countries, number of rural and urban sites, collected samples, techniques used, and species richness.*


#### **Table 3.**

*Species recorded in the studies analysed, their distribution (urban versus rural) and mean intensity.*

in Argentina there are records at all latitudes, except in an arid zone in the northwest, close to the Andes mountains. Species richness was correlated only with sample size (R = 0.44809, p < 0.05) and varied between sites, from 1 to 10 species

*Distribution of Cestoda collected in Argentina, Chile and Uruguay. A.:* Dibothriocephalus *sp.; B.:* Dipilidium

*The State of Knowledge on Intestinal Helminths in Free-Roaming Dogs in Southern…*

*DOI: http://dx.doi.org/10.5772/intechopen.96125*

(Argentina 1 to 10; Chile 1 to 9; Uruguay 1 to 6) (**Figure 2**).

**Figure 3.**

**61**

caninum*; C.:* Echinococcus *sp.; D.: Taenids.*

*The State of Knowledge on Intestinal Helminths in Free-Roaming Dogs in Southern… DOI: http://dx.doi.org/10.5772/intechopen.96125*

**Figure 3.**

**Parasite species Total**

**Country Number of**

**studies analysed**

*Canine Genetics, Health and Medicine*

**Uruguay** 2 not

**Number of sites analysed**

**Argentina** 48 110 38 76 18,812

**Chile** 19 33 5 28 4,574

reported

**Rural Sites**

not reported **Urban Sites**

not reported

**Total collected faeces (range)**

(4–2417)

(10–972),

7,134 (79–5356) **Richness (Range)**

17 (1–10) 13

14 (1–9) 11

6 (1–6) 2

*Dibothriocephalus*

*Dipylidium caninum*

*Echinococcus granulosus*

**sp.**

**Table 2.**

**Table 3.**

**60**

**Number of Sites**

*collected samples, techniques used, and species richness.*

**Mean prevalence (SD)**

*Eucoleus boehmi* 2 1.8 0.6 2 1.8 0.6 *Capillaria* **sp.** 11 3.9 6.1 11 3.9 6.1

*Spirocerca* **sp.** 3 3.4 2.3 3 3.4 2.3 *Physalopetra* **sp.** 1 1.2 1 1.2

**Number of positive urban sites**

*Summary of studies: Total number of reports analysed for the three countries, number of rural and urban sites,*

**Taenidae** 16 5.1 5.9 12 3.4 4.2 4 10.3 7.5 *Taenia hydatigena* 9 9 10.5 7 3.9 2.7 2 26.8 5.3 *Taenia multiceps* 2 2.5 2.1 1 1 1 4 *Taenia ovis* 1 3 1 3 *Trichuris vulpis* 60 14.7 14.7 53 15.3 15.3 7 10.3 8.7 *Eucoleus aerophila* 4 14.9 8.8 1 17.4 3 14.1 10.5

*Strongyloides* **sp.** 19 12 16.1 14 5.6 4.2 5 30.1 22.7 **Ancylostomatidae** 6 24.2 23.5 3 16 21.7 3 32.3 26.6 *Ancylostoma* **sp.** 66 29 23.4 62 29.7 23.3 3 21.4 27.2 *Uncinaria* **sp***.* 21 17.3 18.5 17 18 20.2 4 14.2 8.8 *Ascaris* **sp.** 8 7.6 6.2 6 9.3 6.1 2 2.5 2.2 *Toxascaris leonina* 13 2.7 3.2 11 2.7 3.5 2 2.4 2.2 *Toxocara canis* 86 13.6 11.6 80 13.4 11.5 6 15.9 12.8

*Oncicola canis* 1 0.3 1 0.3

*Species recorded in the studies analysed, their distribution (urban versus rural) and mean intensity.*

**Mean prevalence in urban sites (SD)**

14 5.7 6.2 10 7.8 6.3 4 0.6 0.4

21 5.6 10.3 16 4.1 9.3 5 10.5 12.8

52 7.9 7.1 14 12.9 9.9 38 6 4.7

**Number of positive rural sites**

**Mean prevalence in rural sites (SD)**

**Number of Techniques used**

*Distribution of Cestoda collected in Argentina, Chile and Uruguay. A.:* Dibothriocephalus *sp.; B.:* Dipilidium caninum*; C.:* Echinococcus *sp.; D.: Taenids.*

in Argentina there are records at all latitudes, except in an arid zone in the northwest, close to the Andes mountains. Species richness was correlated only with sample size (R = 0.44809, p < 0.05) and varied between sites, from 1 to 10 species (Argentina 1 to 10; Chile 1 to 9; Uruguay 1 to 6) (**Figure 2**).

#### **Figure 4.**

*Distribution of Nematoda (part 1) in Argentina, Chile and Uruguay. A.: Ancylostomatidae.; B.:* Ascaris sp.; *C.:* Strongyloides*; D.:* Eucocleus *spp. and* Capillaria *sp.*

The most frequently recorded species was *T. canis* (86 sites), followed by *Ancylostoma* sp. (66); *Trichuris vulpis* (60 sites), and *Echinococcus* sp. (52) (**Table 3**; **Figure 4A, 5B, 3E**, respectively); others were recorded only once, e.g.: Trematoda sp. and *O. canis* in Argentina*,* and *Physaloptera* sp. in Chile. The species detected in Uruguay, except for *Echinococcus* sp., correspond to different taeniid cestodes. Argentina and Chile shared 10 helminth species: *Dibothriocephalus* sp., *D. caninum*

sp., *Echinococcus* sp., *Ascaris* sp., *Capillaria* sp., *Strongyloides* sp.,*T. leonina*,*T. canis*,

*Distribution of Nematoda (part 2) in Argentina, Chile and Uruguay. A.:* Toxocara canis *and* Toxascaris leonina*.; B.:* Trichuris vulpis*; C.:* Spirocerca*; D.:* Physalopetra,*Trematoda* sp. *and* Oncicola canis.

*The State of Knowledge on Intestinal Helminths in Free-Roaming Dogs in Southern…*

*DOI: http://dx.doi.org/10.5772/intechopen.96125*

The species richness in urban areas (20 species) was slightly higher than in rural areas (17 species) (**Table 3**). In addition, a higher number of zoonotic species was recorded in urban areas, species such as *Uncinaria s*p.*, Ancylostoma* sp*.* and *Echinococcus* sp. being widespread and prevalent in the cities (**Table 3**). Many parasite

*T. vulpis*, and *Uncinaria* sp.

**Figure 5.**

**63**

*The State of Knowledge on Intestinal Helminths in Free-Roaming Dogs in Southern… DOI: http://dx.doi.org/10.5772/intechopen.96125*

#### **Figure 5.**

*Distribution of Nematoda (part 2) in Argentina, Chile and Uruguay. A.:* Toxocara canis *and* Toxascaris leonina*.; B.:* Trichuris vulpis*; C.:* Spirocerca*; D.:* Physalopetra,*Trematoda* sp. *and* Oncicola canis.

sp., *Echinococcus* sp., *Ascaris* sp., *Capillaria* sp., *Strongyloides* sp.,*T. leonina*,*T. canis*, *T. vulpis*, and *Uncinaria* sp.

The species richness in urban areas (20 species) was slightly higher than in rural areas (17 species) (**Table 3**). In addition, a higher number of zoonotic species was recorded in urban areas, species such as *Uncinaria s*p.*, Ancylostoma* sp*.* and *Echinococcus* sp. being widespread and prevalent in the cities (**Table 3**). Many parasite

The most frequently recorded species was *T. canis* (86 sites), followed by *Ancylostoma* sp. (66); *Trichuris vulpis* (60 sites), and *Echinococcus* sp. (52) (**Table 3**; **Figure 4A, 5B, 3E**, respectively); others were recorded only once, e.g.: Trematoda sp. and *O. canis* in Argentina*,* and *Physaloptera* sp. in Chile. The species detected in Uruguay, except for *Echinococcus* sp., correspond to different taeniid cestodes. Argentina and Chile shared 10 helminth species: *Dibothriocephalus* sp., *D. caninum*

*Distribution of Nematoda (part 1) in Argentina, Chile and Uruguay. A.: Ancylostomatidae.; B.:* Ascaris sp.;

**Figure 4.**

**62**

*C.:* Strongyloides*; D.:* Eucocleus *spp. and* Capillaria *sp.*

*Canine Genetics, Health and Medicine*


records identified to family level, such as "Ancylostomatidae" or "Strongylids", or the recording of species outside their natural range of distribution, like *Dibothrio-*

*The State of Knowledge on Intestinal Helminths in Free-Roaming Dogs in Southern…*

The presence of a greater number of species, most of which have zoonotic potential, in urban areas than rural ones is probably due to the fact that dogs can roam freely. Dogs spread the parasite eggs, thereby these areas will function as contagion points for both other dogs and humans. A further problem is that deworming in these countries is insufficient [21]. A similar situation has been detected in parks in the United States, where it has been suggested that dogs are at risk of infection with parasites at these sites, and it has been recommended that preventive strategies be considered [30, 110]. Some parasitic infections could become increasingly urbanised, and an estimation for 2050 indicates that up to twothirds of the global population will live in megacities. The slums of these megacities would concentrate high levels of intestinal helminth. Toxocariasis and other urban soil-transmitted helminths are important, yet little studied, health issues in the

The zoonotic broad tapeworm, *Dibothriocephalus* sp., is found in dogs from the

[93, 104]. The records from the northeastern region of Argentina require revision, as there are no molecular studies confirming the identity of these parasites, and there are no records of fish infected by plerocercoids in this zone. Although

*Dibothriocephalus* sp., is not transmitted to humans by dogs, they can act as disseminators of the disease and are often used as sentinel species for the spread of the disease in some areas. *Ascaris* sp. in dogs is distributed mainly in subtropical regions of Argentina, where this parasite is most prevalent in humans [107]. Some parasites are distributed throughout all the latitudes regardless of the type of climate, like *T. canis*.,*T. vulpis*, and Ancylostomatids, as observed in other parts of the world [112–114]. *Echinococcus* sp. is distributed across almost all rural areas of the three countries, although has recently also been registered in cities [35, 47, 64, 115].

The high percentage of parasites with zoonotic potential reinforces the need to establish effective prevention measures, not only with regard to parasitosis in animals but also to transmission to humans. This situation highlights the need for better integration between specialists in animal and human health [74]. A few diseases transmitted by dogs have surveillance mechanisms in humans, but there are many other important zoonoses worldwide, with numerous human cases, which are not kept watch on. Some of these have been recorded in Argentina and Chile, such as those caused by *T. canis*, *Ancylostoma* sp*., A. caninum*, *Uncinaria* sp*.*, and *Strongyloides* sp*.* [30]. Of the main zoonoses recorded in dogs in the three countries, cystic echinococcosis is the only one which has to be reported to the health authorities, since it is of major sanitary importance [115]. The others, like toxocariasis, hookworm and strongyloidiasis are not reported, and records of human cases in these countries are scarce. The status of these zoonoses in humans from southern

Cystic echinococcosis or hydatidosis, produced by *Echinococcus granulosus sensu lato*, is a highly endemic parasitic zoonosis in South American countries, especially in Argentina, Chile, Uruguay and Brazil. It is associated with rural areas dedicated mainly to goat and sheep breeding, and causes significant economic losses [47, 69, 116–118].

endemic zone of the disease, the Andean Patagonia of Argentina and Chile

*cephalus* in the northeast of Argentina.

*DOI: http://dx.doi.org/10.5772/intechopen.96125*

cities of the Americas [111].

**4.2 Zoonoses and human cases reported**

South America is analysed below.

*4.2.1 Cystic echinococcosis*

**65**

#### **Table 4.**

*Characterisation of urban and rural areas in terms of richness and most widespread species, present in Argentina and Chile.*

species showed greater prevalence in urban areas than in rural ones. The only exception to this was *T. canis* which had higher values in the rural areas (**Table 3**). In Chile 8 species were registered in rural areas and 14 in urban locations, whereas in Argentina the species richness was 10 and 16, respectively (**Table 4**).

Of the total taxa recorded, 14 (63.6%) have been registered in humans: *Dibothriocephalus* sp., *D. caninum*, *Echinococcus* (*sensu lato*), Taenidae,*T. multiceps*, *T. hydatigena*, Ancylostomatidae sp., *Ancylostoma* sp., *Uncinaria* sp., *Ascaris* sp., *E. aerophila*, *E. boehmi*,*T. leonina,* and *T. canis.* Some of these species are only occasionally recorded infecting humans, such as *D. caninum,Taenia multiceps, E. aerophila*, *E. boehmi* and *T. leonina.*

#### **4. Discussion**

#### **4.1 State of knowledge and distribution**

Although three databases were used, this work could have some bias due to the exclusion of grey literature, like technical reports, congress abstracts or thesis manuscripts, so some sites or negative data may be excluded in the analysis [109]. The systematic bibliographic review carried out shows that the published and available knowledge of the occurrence and distribution of helminths in dogs is scarce in southern South America; in countries such as Uruguay there are no records other than those obtained within the Echinococcosis National Programmes. Furthermore, in Argentina there are arid regions near the Andes, such as the northwest of the country, where there are no records of parasites in dogs. The same was observed for Chile south to 40°s, except for one record in Punta Arenas, the southernmost city in Chile. Most of the records are associated with large cities and their surroundings, such as Buenos Aires and La Plata in Argentina, and in the area of Santiago de Chile, Concepción, and Temuco in Chile.

Although sample size is the only factor that significantly affected richness, other factors to consider could be the analytical methods used and whether the sample was fixed or not. Sample size affects the results, generating deviations in the number of species and in their prevalence, especially in places where the sample size was too low. On the other hand, a lack of methodological specifications can be observed in the techniques used. This could imply potential biases in the reporting and/or interpretation of data. In order to obtain data of higher quality, a general consensus should be reached on the techniques to be applied. It is also desirable to apply molecular techniques that allow parasite identification to species level, thus solving

*The State of Knowledge on Intestinal Helminths in Free-Roaming Dogs in Southern… DOI: http://dx.doi.org/10.5772/intechopen.96125*

records identified to family level, such as "Ancylostomatidae" or "Strongylids", or the recording of species outside their natural range of distribution, like *Dibothriocephalus* in the northeast of Argentina.

The presence of a greater number of species, most of which have zoonotic potential, in urban areas than rural ones is probably due to the fact that dogs can roam freely. Dogs spread the parasite eggs, thereby these areas will function as contagion points for both other dogs and humans. A further problem is that deworming in these countries is insufficient [21]. A similar situation has been detected in parks in the United States, where it has been suggested that dogs are at risk of infection with parasites at these sites, and it has been recommended that preventive strategies be considered [30, 110]. Some parasitic infections could become increasingly urbanised, and an estimation for 2050 indicates that up to twothirds of the global population will live in megacities. The slums of these megacities would concentrate high levels of intestinal helminth. Toxocariasis and other urban soil-transmitted helminths are important, yet little studied, health issues in the cities of the Americas [111].

The zoonotic broad tapeworm, *Dibothriocephalus* sp., is found in dogs from the endemic zone of the disease, the Andean Patagonia of Argentina and Chile [93, 104]. The records from the northeastern region of Argentina require revision, as there are no molecular studies confirming the identity of these parasites, and there are no records of fish infected by plerocercoids in this zone. Although *Dibothriocephalus* sp., is not transmitted to humans by dogs, they can act as disseminators of the disease and are often used as sentinel species for the spread of the disease in some areas. *Ascaris* sp. in dogs is distributed mainly in subtropical regions of Argentina, where this parasite is most prevalent in humans [107]. Some parasites are distributed throughout all the latitudes regardless of the type of climate, like *T. canis*.,*T. vulpis*, and Ancylostomatids, as observed in other parts of the world [112–114]. *Echinococcus* sp. is distributed across almost all rural areas of the three countries, although has recently also been registered in cities [35, 47, 64, 115].

#### **4.2 Zoonoses and human cases reported**

The high percentage of parasites with zoonotic potential reinforces the need to establish effective prevention measures, not only with regard to parasitosis in animals but also to transmission to humans. This situation highlights the need for better integration between specialists in animal and human health [74]. A few diseases transmitted by dogs have surveillance mechanisms in humans, but there are many other important zoonoses worldwide, with numerous human cases, which are not kept watch on. Some of these have been recorded in Argentina and Chile, such as those caused by *T. canis*, *Ancylostoma* sp*., A. caninum*, *Uncinaria* sp*.*, and *Strongyloides* sp*.* [30]. Of the main zoonoses recorded in dogs in the three countries, cystic echinococcosis is the only one which has to be reported to the health authorities, since it is of major sanitary importance [115]. The others, like toxocariasis, hookworm and strongyloidiasis are not reported, and records of human cases in these countries are scarce. The status of these zoonoses in humans from southern South America is analysed below.

#### *4.2.1 Cystic echinococcosis*

Cystic echinococcosis or hydatidosis, produced by *Echinococcus granulosus sensu lato*, is a highly endemic parasitic zoonosis in South American countries, especially in Argentina, Chile, Uruguay and Brazil. It is associated with rural areas dedicated mainly to goat and sheep breeding, and causes significant economic losses [47, 69, 116–118].

species showed greater prevalence in urban areas than in rural ones. The only exception to this was *T. canis* which had higher values in the rural areas (**Table 3**). In Chile 8 species were registered in rural areas and 14 in urban locations, whereas

*Characterisation of urban and rural areas in terms of richness and most widespread species, present in*

Although three databases were used, this work could have some bias due to the exclusion of grey literature, like technical reports, congress abstracts or thesis manuscripts, so some sites or negative data may be excluded in the analysis [109]. The systematic bibliographic review carried out shows that the published and available knowledge of the occurrence and distribution of helminths in dogs is scarce in southern South America; in countries such as Uruguay there are no records other than those obtained within the Echinococcosis National Programmes. Furthermore, in Argentina there are arid regions near the Andes, such as the northwest of the country, where there are no records of parasites in dogs. The same was observed for Chile south to 40°s, except for one record in Punta Arenas, the southernmost city in Chile. Most of the records are associated with large cities and their surroundings, such as Buenos Aires and La Plata in Argentina, and in the area of Santiago de Chile,

Although sample size is the only factor that significantly affected richness, other factors to consider could be the analytical methods used and whether the sample was fixed or not. Sample size affects the results, generating deviations in the number of species and in their prevalence, especially in places where the sample size was too low. On the other hand, a lack of methodological specifications can be observed in the techniques used. This could imply potential biases in the reporting and/or interpretation of data. In order to obtain data of higher quality, a general consensus should be reached on the techniques to be applied. It is also desirable to apply molecular techniques that allow parasite identification to species level, thus solving

in Argentina the species richness was 10 and 16, respectively (**Table 4**). Of the total taxa recorded, 14 (63.6%) have been registered in humans: *Dibothriocephalus* sp., *D. caninum*, *Echinococcus* (*sensu lato*), Taenidae,*T. multiceps*, *T. hydatigena*, Ancylostomatidae sp., *Ancylostoma* sp., *Uncinaria* sp., *Ascaris* sp., *E. aerophila*, *E. boehmi*,*T. leonina,* and *T. canis.* Some of these species are only occasionally recorded infecting humans, such as *D. caninum,Taenia multiceps,*

**Country Urban Rural**

*Most widespread species*

*Ancylostoma* sp. *Trichuris vulpis*

*Ancylostoma* sp. *Trichuris vulpis*

*Richness (Range)*

*Mean richness*

10 (1–8) 1.7 *Echinococcus*

8 (1–6) 3 *Echinococcus*

*Most widespread species*

sp.

sp.

*Similarity*

7/17

7/14

*Mean richness*

**Argentina** 16 (1–10) 3.8 *Toxocara canis*,

**Chile** 14 (1–9) 2.8 *Toxocara canis,*

*E. aerophila*, *E. boehmi* and *T. leonina.*

*Richness (Range)*

*Canine Genetics, Health and Medicine*

**4.1 State of knowledge and distribution**

Concepción, and Temuco in Chile.

**4. Discussion**

**64**

**Table 4.**

*Argentina and Chile.*

From 2009 to 2014, a total of 29,559 new human cases of cystic echinococcosis were registered in these countries. The average fatality rate across the three countries was 2.9%, suggesting that the disease causes approximately 880 deaths annually. The most affected are children <15 years of age, which is indicative of a persistent environmental risk leading to new cases [69, 115]. In the countries analysed, Government Control Programmes have been addressed, and surveillance of the disease from a holistic perspective based on Primary Health Care has been implemented [64, 69, 115, 117]. The number of human cases has a heterogeneous geographical distribution in Chile and Argentina, showing an increase towards the south [116, 118].

[129, 130]. In Chile, the seroprevalence is much lower (0.25%) in blood donors from Arica and La Union. Human infections by *S. stercoralis* in this country are therefore

This review shows that knowledge of canine helminths in southern South America is scarce. The studies published on dog parasites are not equally distributed across the three countries, with Uruguay presenting the least amount of available information. Data on dog parasites in southern South America is still too incipient for identification of a clear distribution pattern. Homogenisation of criteria would be beneficial, since the methods used are diverse and heterogeneous, some studies using only flotation or sedimentation techniques. Numerous parasitic species were recorded, many of which are zoonotic and widely distributed throughout both urban and rural areas of these countries. The risk of dogs becoming infected is high given the number of parasites present and the style of pet ownership in the communities of these countries, where dogs are allowed to roam freely, and veterinary care is scarce. The high percentage of zoonotic helminths reinforces the need to establish effective prevention measures, not only for parasitosis in animals but also for transmission to humans. Considering that people in both urban and rural areas are at risk of being infected with zoonoses transmitted by dogs, given the high levels of infection they present in their faeces, a One Health approach to public health would be desirable, such that humans and dogs should be treated concomitantly to control the parasites. Furthermore, it would be desirable to implement measures such as control of the canine population, mass treatment of dogs with anthelmin-

endemic, with very low frequency in apparently healthy individuals [131].

*The State of Knowledge on Intestinal Helminths in Free-Roaming Dogs in Southern…*

tics, education programmes and healthcare alert systems.

Luciano Ritossa, Gustavo Viozzi and Verónica Flores\*

provided the original work is properly cited.

This work was funded by PICT 1385–2017 and UNCo B225.

Laboratorio de Parasitología, Instituto de Investigaciones en Biodiversidad y

Técnicas - Universidad Nacional del Comahue), San Carlos de Bariloche, Río Negro,

© 2021 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium,

Medioambiente (Consejo Nacional de Investigaciones Científicas y

\*Address all correspondence to: veronicaroxanaflores@gmail.com

**5. General conclusions**

*DOI: http://dx.doi.org/10.5772/intechopen.96125*

**Acknowledgements**

**Author details**

Argentina

**67**

#### *4.2.2 Toxocariasis*

Toxocariasis is an infection that has a worldwide distribution and is a very important zoonosis due to its frequent occurrence in humans [119]. The estimate of the overall worldwide prevalence of *T. canis* in dogs of 11.1% represents 100 million dogs, which should alert Public Health experts and policy makers to the need for effective intervention programs [114, 120]. This parasite species has high biotic potential since its eggs contaminate water, soil, grass, and pet fur [51]. The results presented here regarding *T. canis* in dogs of southern South America show higher prevalence values (around 13%) than the overall prevalence registered worldwide. Also, the risk of infection is similar in urban and rural areas, as suggested in Chile [105]. In Argentina, numerous studies that analysed the seroprevalence of toxocariasis in both children and adults from urban and rural areas reported results varying between 28% and 80% [51, 121, 122]**.** In Chile, the seroprevalence of this parasitosis varies between 1.3% and 25.4% [105]. Although in Uruguay there are no published records of seroprevalence in humans [123], a recently published work reported that from 2014 to 2018, 20 children had been treated in the public health system for ocular and visceral *larva migrans* syndrome [123].

#### *4.2.3 Ancylostomiasis*

Dog hookworms are *Ancylostoma caninum*, *Ancylostoma braziliense*, and *Uncinaria stenocephala,* and their eggs can be found in faeces. The larvae of these parasites can cause cutaneous *larva migrans* in humans [124]. The main causal agent of *larva migrans* worldwide is *A. braziliense*; however, the causative agents vary among geographical areas, even within a single country. This disease is mainly endemic to tropical and subtropical developing countries with high average annual temperatures and humid climates, predominating in America from the southern United States, through Mexico, Central, and reaching South America. It is especially prevalent in areas where dogs roam freely, and on sandy, wet soils, such as beaches and playgrounds [124]. In Argentina, records of human cutaneous *larva migrans* correspond to the *Wichi* aboriginal communities in the subtropics of the northwest of the country [103], or to people who had travelled to Brazil [125]. In Chile, there are also few reports of this disease, and they correspond to a 3-year-old patient who acquired the disease in an urban area [126], and to an adult who had been infected on a trip to Brazil [127].

#### *4.2.4 Strongyloidiasis*

Strongyloidiasis is prevalent in remote socioeconomically disadvantaged communities around the world, and dogs can act as reservoirs of human strongyloidiasis [128]*.* This parasitosis is registered in the north of Argentina, with similar infection values in both rural and urban populations and an overall seroprevalence of 19.6%

*The State of Knowledge on Intestinal Helminths in Free-Roaming Dogs in Southern… DOI: http://dx.doi.org/10.5772/intechopen.96125*

[129, 130]. In Chile, the seroprevalence is much lower (0.25%) in blood donors from Arica and La Union. Human infections by *S. stercoralis* in this country are therefore endemic, with very low frequency in apparently healthy individuals [131].
