Lice in Horses

Causes of Lice

Typically, horses that are underweight or in poorer condition are more susceptible to lice infestations. Healthy horses have a stronger immune system and can usually fight off an infestation unless they are housed in stressed or poor conditions.3 Other potential causes of lice include:

• Physical contact with another lice-infested horse
• Using tack or grooming tools that are lice-infected

Diagnosing Lice in Horses

Lice are generally diagnosed based on symptoms and the presence of nits (eggs), which are visible to the naked eye. If no nits are seen, then a veterinarian may also perform a skin scraping to check for parasites under a microscope because mange can cause similar symptoms.

Treatment

The first step is to treat the horse with either a topical de-lousing powder or medication.4 Common treatments are permethrin-based dust, shampoos, or rinses. Be cautious when applying treatment to irritated skin because it may sting.

When applying any medication powder, take care not to inhale it, and to wash up after you apply it. Wear gloves and a dust mask to avoid contact with the chemicals.

All equipment that could carry lice or nits must be washed as well. Blankets and washable equipment can be laundered and dried with high heat, or even boiled.

Prognosis for Horses with Lice

With help and treatment, a horse is likely to recover from lice without much concern. The bigger challenge is making sure your horse is healthy and has comfortable living conditions to reduce stress and the likelihood of lice infestations.

Lice are species-specific, meaning that bird lice generally don't live on people or dogs, and horse lice don't typically infect people. Neither you nor your other pets are likely to get lice from your horse. The lice are transferred from horse to horse by direct contact or through shared brushes, blankets, and equipment.

How to Prevent Lice

The best way to ward off lice is to keep your horse in spacious, sanitary conditions and feed it a nutritious diet.

If you bring a new horse home, it should be kept separate from other horses to prevent any problems, including lice, to the resident herd.5 In a busy barn, it's a good idea that each horse has its own brushes and equipment because shared grooming tools and blankets can spread many skin problems like lice, ringworm, and mange.