Biting and Sucking Lice

Both biting (Figure 11) and sucking lice (Figure 12) parasitize horses. Both types are host specific to horses, mules and donkeys.

Horses infested with lice usually look poorly groomed. The hair coat looks poor and the animals rub and scratch to

alleviate the itching caused by feeding activity of the lice. The ini-tial locations of infestation are generally on the head, neck, mane or tail; however, as numbers of lice increase, other areas of the body become infested. Heavy louse populations may predispose the horse to other disease conditions and reduce the vigor of the animal.

Figure 12.
Horse sucking louse
(Haematopinus asini).

Both types of lice found on horses have similar biology's. Eggs are glued to the hair on the horse, usually close to the skin. The eggs hatch in about seven days to three weeks depending on species. Immature lice remain on the horse throughout three nymphal stages which last about a month before molting into adult lice. Adult lice remain on the horse during their entire life. Lice which are removed from the animals die within a short time. Lice are transferred from one horse to another by direct contact with other animals.

The horse sucking louse (Figure 12) feeds on blood and the biting louse (Figure 11) feeds on shed skin or scurf and on secretions from the skin. Both types of lice reproduce throughout the year. However, these pests are most common during the winter months. Good grooming and adequate nutrition are important to maintain the health of the horse. Grooming provides an excellent opportunity to inspect the horse for lice.

Figure 11.
Horse biting louse
(Bovicola equi).