Horse Lice 101

Horse Lice 101

What are lice?

Lice are classed as a parasite in the animal kingdom as they live off a “host” or rather a horse. Two types of these parasitic insects infect horses:

* Chewing lice, Damalinia equi, feed on sloughed-off dead skin cells: these are more likely to affect the neck, flanks and the base of the tail.

* Biting or sucking lice, Haematopinus asini, feed on blood: this species prefers longer hair and may be found under the forelock and mane, the tail and on the pasterns of long-feathered horses.

What do lice look like?

Lice are 1-2mm in length and are brown in colour. They can be seen with the naked eye during careful examination. If you part the hair and watch for a moment, you can see them moving around.

The lice lay eggs called nits in the horse's hair, coat and mane. Both nymphs and adults will cause the itching associated with lice. They too are also visible and are tightly adhered to the hairs of the coat.                                                                                           Horse Lice and Eggs

What time of the year do they affect horses?

Lice tend to be more common during the winter and early spring months when horses congregate closer together, and they have long, dense coats that create the right environment for the lice to thrive, but they can occur at any time of year.

How are they spread?

Lice are mainly spread by direct contact from one horse to another, but can be spread indirectly by shared rugs and grooming equipment. A louse can survive for 2-4 weeks in an environment with favourable conditions, but more frequently die off within a week.

Can humans catch horse lice?

Fortunately, humans cannot contract lice from a horse. The lice that live on people are a different species. However, they can affect mules and donkeys.

How will I know if my horse has got lice?

The most obvious tell-tale symptom is continual and constant itching.

What are the symptoms of lice?

The symptoms of lice include:

* Loss of lustre to horse's coat.

* Loss of hair from neck.

* Loss of hair from shoulders.

* Matting of body hairs.

* Mane and tail become matted.

* Frequent itching of the skin.

* Rubbing against poles, walls, etc.

* Biting at the skin.

Do I need to treat it?

Absolutely! Not only can lice be extremely uncomfortable for the horse, severe cases can cause anaemia.

How should I treat lice?

There are several types of topical solutions available to treat it in the form of sprays, shampoo, powder and lotion. The good thing about the range of products available is that if the weather is too bad or it’s too cold to bath your horse, you can go for a spray, lotion or powder.

Read and follow label instructions and precautions carefully. Many treatments need to thoroughly coat the skin to be effective, but some products may irritate small cuts and abrasions.

Whilst the topical solutions will kill the lice, they will not kill the eggs. So, the treatment will need to be re-applied in two weeks to prevent any unhatched eggs from causing the same problem.

Do not be tempted to use treatments that are for human lice on your horse as these will not work. Likewise, be sure to use a lice shampoo made specifically for horses as using a lice shampoo made for cattle or sheep can cause severe skin reactions and/or hair loss in horses.

What’s the best way to prevent the lice from coming back?

Lice can be passed directly from horse to horse, as well as via shared tools and equipment. So, once you’ve treated your horse, keep him away other horses you may believe are infected.

* Be sure to brush your horse on a regular basis, especially when his coat is longer, i.e. in winter.

* Clean and sterilise tack regularly.

* Wash saddle pads and numnahs at a high temperature to kill the lice and their eggs.

* Clean brushes and small tools with an insecticide.

For persistent cases:

* Steam or wash rugs at a temperature above 50°C.

* Spray or scrub down stable walls or wooden fences.

* Change straw or shavings bedding.

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Kim Horton

Co-Founder of EQUUS and a keen equestrian, when Kim's not at her desk she's with her horse, Waldo.


  • Mandy Williams posted on June 14 2019 at 09:06 AM

    My shetland had lice. His coat was patchy and matted. Due to it being winter his coat was unbelievably long do the first thing I did was have him clipped out to combat the pesky buggers. I used a powder I got from my local horse shop. Thankfully after using it for around 2 Wks I’d won the battle of the lice

  • Lyn Hannant posted on April 22 2020 at 10:04 PM

    I’ve never been able to find out where lice come from. Do they ‘hibernate’ during the winter on the horse’s coat? Do birds bring them when they perch on the back of a horse to pick hair for nesting? Anyone out there know, please?

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