**10.3 Pathogenesis**

The whole developmental process of Toxoplasma gondi requires two hosts, the definitive host, cat and the intermediate host (all warm blooded animals).

There are three stages of Toxoplasma gondii that are infectious for all hosts: tachyzoites, bradyzoites, and oocysts.


#### **10.4 Clinical findings**

There are a few reports of clinical toxoplasmosis in cattle associated with fever, dyspnea, nervous signs and abortion (Taylor et al., 2007).Toxoplasma is not significant in bovine abortion (Radostits et al., 2008). In small ruminants, particularly in sheep clinical signs include fever, abortion, prenatal mortality in lambs, generalized tremor, and dyspnea (Taylor et al., 2007; Radostits et al., 2008).

#### **10.5 Diagnosis**

494 A Bird's-Eye View of Veterinary Medicine

al., 2009). Felids are the definitive hosts, and there are wide range of intermediate hosts in

**Specie Affinity site Intermediate hosts Definitive host** 

Toxoplasmosis is one of the most common parasitic infections of man and other warmblooded animals in most parts of the world (Hill et al., 2002). The disease is a major cause of ovine abortion in many countries (Christensen et al., 2009). Seroprevalence studies show high rates of infection in farm animals. Major importance of disease in farm animals is its zoonotic potential. Source of infection for sheep, and cattle is the oocyst passed in the feces of the cats. Cats shed oocysts by their feces. Cats infected by ingesting tissues of

The whole developmental process of Toxoplasma gondi requires two hosts, the definitive

There are three stages of Toxoplasma gondii that are infectious for all hosts: tachyzoites,




There are a few reports of clinical toxoplasmosis in cattle associated with fever, dyspnea, nervous signs and abortion (Taylor et al., 2007).Toxoplasma is not significant in bovine abortion (Radostits et al., 2008). In small ruminants, particularly in sheep clinical signs include fever, abortion, prenatal mortality in lambs, generalized tremor, and dyspnea

importance in livestock animals (Dubey et al., 1998; Radostits et al., 2008).

Cattl, sheep, goats, man, and all warm blooded animals

cats

lung, reproductive system, central nervous system

host, cat and the intermediate host (all warm blooded animals).

this disease (Radostits et al., 2008).

Toxoplasma specie is shown in table 11.

Toxoplasma gondii Muscle, liver,

intermediate hosts (Radostits et al., 2008).

brain, eye, skeletal, and cardiac muscle.

(Taylor et al., 2007; Radostits et al., 2008).

Table 11. Toxoplasmosis

**10.2 Epidemiology** 

**10.3 Pathogenesis** 

bradyzoites, and oocysts.

intermediate host.

**10.4 Clinical findings** 

Diagnosis is based on the clinical signs, presence of the characteristic small white necrotic foci in cotyledons. ELISA test is also used to detect antibodies in fetal and maternal serum. Indirect fluorescent antibody test can be used for fluid collrcted from the fetal thorax or abdomen. Serological examination of dam can be used for diagnosis (Matthews, 2009).

### **10.6 Treatment and control**

Combination of sulfamethazine (SMZ) and pyrimethamine (PMA) can be effective in pregnant ewes. The drugs are effective against the proliferating parasites in the acute stage of the disease (Radostits et al., 2008). The combined dose of (SMZ) and (PMA) is administered over 3 days for 3 periods, commencing on days 110, 115 and 130 of gestation. SMZ is injected s.c. at an initial dose of 5 ml/ 10kg body wt on the first day of a given treatment priod with subsequent doses of 2.5 ml/10kg on each of the next 2 days. PMA is administered at 2 mg/kg on the first day and at 1mg/kg on the subsequent 2 days of each treatment period (Buxton et al., 1993).

Because the cats are the only definitive host of toxoplasmosis, it should be kept away from animals farm, and also feeding and drinking water should be prevented from contamination by cat feces. Aborted fetus and excreta, must be strictly disinfected.

It is important to reduce the risk for human disease associated with consumption of infected meat (Radostits et al., 2008).
