Ectoparasites

Parasitic skin diseases present in Europe are economically important and include lice, mange and warble infestations (Fadok, 1984; Lonneux and Losson, 1996).

Lice are highly host-specific parasites that spend their complete life cycle on the host. The lice are spread by direct contact or contact with bedding or other inanimate objects that an infected animal has rubbed to relieve the itching sensation. Lice are a greater problem in winter (stabling period) when nutrition may be poor, crowding occurs, which facilitates spread of infection, and animals have long hair coats, which provide a good environment for louse reproduction. Exposure to cold and debilitating disease increases the likelihood of heavy infestation. Some animals may remain infected all year round and infect other animals the next winter. When this happens, the infected animals should be treated for lice when housed or in the autumn.

Psoroptic mange is caused by Psoroptes ovis and is the most common and important mange type in Western Europe. The condition is more common in winter than in summer months, and beef cattle (Charolais, Belgian White Blue) are more susceptible. Sarcoptic mange is becoming rare in Western Europe. Chorioptic mange (Chorioptes bovis) is most evident in the winter in stabled cattle, particularly dairy animals. Spread of mange occurs by contact as well as by inanimate objects, and is a greater problem in winter (stabling period).

Warbles in Europe are mainly larvae of the fly Hypoderma bovis and, to a lesser extent, H. lineatum. Animals are infected in autumn. During winter, larvae (H. bovis) migrate in the connective tissue and fat surrounding the spinal cord. The larvae migrate to the subcutaneous region over the back, usually in early spring.

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