Lice in cats and dogs

photo of cat and dog


Louse infestations in cats and dogs are quite rare. They are most common in vulnerable pets (young, old or unwell) and pets kept in dirty, overcrowded conditions.

Lice cause itchy, scaly skin, dandruff and a dry coat. Some lice cause illness and anaemia by sucking blood.

Treatment from your vet to cure the problem is often relatively simple and the sooner you get the problem diagnosed the easier it is to treat.

Lice explained

Lice are tiny insects that can cause itchy, flaky, dry skin in dogs and cats. Some of them suck blood, which can cause illness and anaemia (especially in young or very small pets).

Lice don’t normally trouble healthy animals too much, they are more likely to affect vulnerable pets (young, old or unwell) and those living in dirty, overcrowded conditions.

Lice eggs can survive in the environment and hatch out for 2-3 weeks after they have been laid.

Lice tend to stick to their preferred species (i.e. cats or dogs), only very rarely do they cross over to others. This means it’s difficult from a human to catch lice from their pets.


If your pet if suffering from a louse infestation they may show some of the following symptoms:

  • Itchy skin
  • Scaly skin
  • Dandruff
  • Dry coat
  • Lice (slow moving and brown) and eggs (white dots on the fur) visible in coat
  • Hair loss (alopecia)
  • Pale gums (due to anaemia).

When to contact your vet

Contact your vet for an appointment if you suspect your pet has lice, or notice any of the symptoms listed above.

You know your pet best. If they don’t have the symptoms listed above but you are still concerned it’s always best to contact your vet.



  • Your vet is likely to suggest an intensive course of insecticide to kill the lice. They will advise you which treatment to use and how often.
  • Treat all other animals in regular, close contact.
  • Treat pet bedding, brushes, coats and the household (eggs will continue to hatch in the environment for 2-3 weeks after they have been laid).

Other treatments

  • Your vet may prescribe medication to treat any skin wounds or infections.
  • If your pet has become unwell or anaemic, they may need admitting into the veterinary hospital for more intensive care.

Avoid other pets

  • Keep your pet away from other pets until they have recovered.

Outlook and prevention

Outlook is excellent once your pet has received treatment from your vet and their environment is treated. Follow instructions carefully and keep a close eye out for lice for a few weeks after treatment. Pets who have become unwell or anaemic due to a louse infestation may take a bit longer to recover.

Regularly de-flea your pets, many flea treatments are also effective against lice. Keep your pets in warm, clean, comfortable conditions.

Published: January 2019

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Written by vets and vet nurses. This advice is for UK pets only.

Illustrations by Samantha Elmhurst