Lice - itchy horses

Has your horse started scratching all the time?
There are many causes of itching in horses, ponies and donkeys - including:

  • sweet itch (hypersensitivity to midge bites usually causing mane, tail, face and underside of abdomen itching)

  • feather mites (chorioptes), causing itching and stamping of usually feathered horses limbs

  • pinworm, causing itching and irritation around and under the tail

  • a long list of possible allergies caused by skin contact, drug reactions or diet

  • and also some medical conditions can cause sore or itchy skin

But we are covering lice today!

There are many different types of lice - but two are seen in the UK and we have included pictures of the most common one (Damalinia) here.

The lice are 2 to 5 mm in size and are usually found around the base of the hairs or on the skin. They are visible using a good light and parting the hair of your horse, and can look like walking dandruff! They can often come to the surface of the hair when your horse sweats.

Eggs can also be seen stuck to the hairs.


  • Itching is the obvious one - horses can be very intensely itchy, often to the point that they scratch and break parts of your stable, cause raw areas on their skin and hair loss.

  • Not all horses have a big reaction to lice - some can show just flaky skin and a poor quality coat, so parting the hair and looking for lice in good light is important.

  • Lice are common in young, older (especially horses with Equine Cushings) and native breeds, but can be seen on any horse.

  • They are seen more often in winter months.

  • If you are not sure call your vet to come and examine your horse.


  • For your horses we would recommend using a product called Deosect or Switch / Z-Itch. Deosect is a product containing cypermethrin, Switch and Z-Itch contain permethrin all of which kill larvae and adult lice. Follow the instructions and remember you will have to repeat the treatment several times as the eggs present on your horse will still hatch requiring another dose to kill newly hatched lice.

  • You will have to treat any in contact horses - lice are easily passed on so field companions or neighbouring horses are likely to have them too

  • Remember to clean and disinfect grooming kit and wash your horses rugs

  • Lice powders can be effective also, but few are tested and licensed for use on horses

  • All horses receiving treatment should have had Section IX (nine) of their passport signed to indicate they cannot enter the food chain

Itching can take a few days to start improving once on treatment and you may still find lice but they should not be moving!


As with many worming treatments we are starting to see some evidence of resistance to lice treatments - if you are struggling to resolve a lice problem please contact us.


Horse lice do not infest people - and vice versa, they are specific to that species. They will come onto people and clothes - and can cause a rash usually up arms, but are unlikely to stay!

Also be careful not to have contact with other horses if you know yours has lice as they can come off your clothes, your rugs or grooming kit onto another horse.

Adam X

Updated: Feb 2018