**2. Life cycle**

**Figure 1.** *Haematopinus tuberculatus* female with nit (×19.4).

in cattle. In severe cases, especially in calves, the organisms can lead to anemia, weight loss, and damaged pelts. Pregnant animals may abort. Lice eggs or nits are attached to hairs near the skin. Three nymphal stages, or instars, occur between egg and adult, and the growth cycle takes about 1 month for all species. Lice cannot survive for more than a few days off the host. Caused by several species (**Table 1**), five louse species are known to be able to infect cattle: three species of the genus Haematopinus, along with the species *Linognathus vituli* and *Solenopotes capillatus*. *Haematopinus tuberculatus* (**Figure 1**) is a typical parasite of the domesticated Asian buffalo, which is known to infest cattle as well [6] as the young animals may be

*Linognathus vituli* (long-nosed cattle louse) Most commonly found over withers, lateral shoulders, and dewlap.

*Solenopotes capillatus* (little blue cattle louse) Infestations tend to be heavier in anterior portions of the body,

*Haematopinus quadripertusus* (cattle tail louse) Heavy infestations may extend to dewlap or surround the eyes.

may be found in clusters

mainly on head and face

Most commonly found in the dorsum. Infestation may extend

May have generalized distribution over animal. In early infestations

In heavy infestations, may be found over most of the body. Often

including the ears, during warm weather. Found in distinct clusters,

Adults often confined to the tail, eggs commonly noted on tail switch

found on front half of the host from ears to dewlap

cranially to head and caudally to tailhead

**Lice species Localization of the lice**

Chewing lice

louse, red louse)

Bloodsucking lice

louse)

*Damalinia bovis*/*Bovicola bovis* (cattle biting

80 Bovine Science - A Key to Sustainable Development

*Haematopinus eurysternus* (short-nosed cattle

**Table 1.** Site predilection of cattle lice [3–5].

Lice undergo an incomplete metamorphosis. The life cycle takes about 4 to 5 weeks to complete. Lice lay eggs that hatch after 6–7 days. Each female deposits 20–50 (30–40) eggs (nits) during her lifetime. She deposits them one by one to single hairs. Incubation lasts 4–20 days. The eggs hatch and develop through three nymph stages to adults. Nymphs look like adults but are smaller. Adult life lasts for 2–6 weeks. Lice tend to prefer the white areas of black-and-white cattle. Off the host, most lice survive only for a few days. Survival of lice is reduced by warm weather, cattle self-grooming, loss of hair coat and good nutrition of the host [3, 4].

susceptible for other diseases. Cattle with hair loss may be discounted at the saleyards. Skin that has been irritated by lice has a rough surface with complete loss of hair in some areas, which gives the animals an unthrifty appearance and reduces both the slaughter value and the usability of skin and hide for industrial processing [15]. In the UK, analysis of hides in abattoirs resulted in more than 80% showing some degree of lice damage. In recent years, hide or fleece damage caused by lice has been increasingly recognized as a significant effect of lice infestations. The damage is described as areas of grain loss up to 3 mm diameter that are seen

Louse Infestation of Ruminants

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http://dx.doi.org/10.5772/intechopen.79257

For all age classes of cattle, stressors such as high stocking density, poor feed quality, gestational status, and underlying health issues are often contributing factors to susceptibility and

Factors determining the severity of infestation with blood-sucking lice include the animals' age and sex and also the season. Numerous studies have been conducted to investigate correlations between the distribution of lice and the age of host animals within herds. Occurrences of bovine pediculosis do not show seasonal variation in countries with a warm climate. However, in the temperate zone and in colder regions, the most severe infestations occur in late winter and early spring, when the weather is cold and damp and the animals have the thickest coat of hair. The coat of hair serves as a habitat and shelter for lice, and provides optimum conditions for their propagation. During the year, the highest increase in the louse population occurs when cattle or buffaloes are kept indoors for the winter. In late spring, the number of lice suddenly decreases. It then remains at a low average level during the summer months when the hair coat becomes thinner, which provides a less favorable habitat for lice, because the high temperature of the skin surface and direct exposure to sunlight reduce the intensity of their development [2, 15]. Other authors have also observed seasonal occurrences of pediculosis, reporting that the population of sucking lice starts to grow in late winter, reaches its peak in the spring and its nadir in the summer and autumn months. In India, the highest 'louse index' was found in January and the lowest in June [17]. According to the results obtained by Hussain et al., the louse population reaches its highest level in February, and the environmental conditions

continue to be favorable for survival and propagation of lice in March and April [9].

In a survey conducted in Pakistan [18], the prevalence of lice was significantly (P < 0.05) higher in cattle than in buffaloes: 144 out of 600 randomly selected cattle (24%) and only 113 out of 600 randomly selected buffaloes (18%), kept under conditions identical to those of the cattle, proved to be infected. The prevalence of louse infestation in cattle has been reported by researchers from different countries [19–21] have reported varying prevalence rates of louse infestation in cattle in association with differences in the ecological, geographic and weather conditions. Animals kept in closed management systems are not exposed to direct sunlight, which favors the survival of lice. When cattle are kept in open barns, houses with outdoor runs or in free range management system, their skin surface is directly exposed to sunlight and consequently becomes drier, which reduces the survival chances of lice and decreases the intensity of their propagation [10]. A total of 762 water buffaloes were examined. *H. tuberculatus* was found in the 11.0% (14/127) of the farms and in the 4.5% (34/762) of the animals. The presence of *H. tuberculatus* should be routinely considered because it is a cause of serious health, production and economic damages in intensive breeding buffaloes [22]. According to

on dyed crust leather [16].

degree of infestation.

Lice infestations develop mostly in the colder season and peak in late winter and early spring. Skin temperature has also been correlated with the severity of louse infestation. Lice decline during the hotter season. Stabling the animals during the winter season favors overcrowding, which makes contact transmission easier. The poorer diet during winter weakens the natural defense of cattle against the lice infestations. The denser and more humid hair coat in winter offers an excellent environment for lice development as well.

In spring, food improves quickly when the herds start grazing fresh pastures. The shorter hair and the exposure to the sun reduce skin humidity, and free grazing ends overcrowding in the winter quarters, which also diminishes transmission. As a consequence, lice infestation usually recedes spontaneously during the summer season. However, a few lice usually manage to survive in some animals that will re-infest the whole herd when it comes back to the winter quarters for the next winter [3, 4].
