Lice in Horses
Lice are widespread parasitic pests that can infest many animals' coats, including horses. They typically target horses that live in overcrowded, unsanitary conditions or those that are stressed for any number of reasons. There are two species of lice and the distinction is how they feed: one species feeds through biting and chewing on hair and dead skin, while the other feeds through sucking the blood of the host animal. Both cause extreme itching and skin damage due to horses scratching their irritated skin.
What Are Lice?
Lice are tiny parasitic insects that live in the hair coat of horses and other mammals. Lice infestations can be an indication of poor care and/or poor nutrition, but they occasionally occur for no apparent reason. They can be common in stables where close quarters and shared equipment make the spread of lice easy.
The two species of lice that impact horses are Haematopinus asini (H. asini), the blood-sucking type, and Damalinia equi (D. equi), the skin biting type.1
Symptoms of Lice in Horses
Lice like to breed in horses' thick winter coats, but they can be present year-round. They will migrate all over the horse's body, including the mane and tail. Wherever they are, they cause horses a lot of discomfort.
Symptoms
- Itching
- Irritated skin
- Visible raw patches on the skin
- Rough hair coat
- Lethargy
A lice-infested horse will be intensely itchy, especially around the base of the tail, mane, and head. The lice lay eggs called nits in the horse's hair coat and mane. These nits will hatch into nymphs that mature into egg-laying adults. Both nymphs and adults will cause the itching associated with lice. As the horse tries to relieve the itching by rubbing itself on fences, trees, or stall walls, it can rub raw patches on its skin.2
A horse can be so uncomfortable that it will appear listless or colicky and become very run down. Depending on the type of lice, the parasites will either suck the horse's blood or feed off of dead skin cells, both of which are itchy. If the horse is infested with the sucking louse, blood loss may be severe enough to cause anemia, which will make the horse feel lethargic.