Many people may ask what lice in cats and dogs are. The answer to this is lice are a type of wingless insect, which live on the skin of animals for their whole life and can only survive for a few days in the environment. However, they can be challenging to deal with, so read on for more details!
All about lice
Unlike other parasites, lice are often host specific, meaning they will only infest certain species. Lice can be either chewing or sucking lice. The chewing louse will chew the skin from the host whereas the sucking louse will suck the blood.
There are two types of lice that infest dogs here in the UK
- The ‘Dog chewing louse’. This chewing louse, also called Trichodectes canis, is found all over the world. These lice can be irritating to dog when present in large numbers but can also pass on the tapeworm Dipylidium caninum. These lice will live on almost all species of canine, and like to be in the back, neck and head area.
- ‘Linognathus setosus’. This sucking louse feeds on the blood of affected dogs. This louse is only 5-2.5mm long, this bloodsucker can cause problems when present in large numbers, as especially in young, unwell or underweight dogs as this louse can lead to anaemia (low blood levels).
The main louse infesting the cat is the cat louse, Felicola subrostrata, is a biting or chewing louse. It is a tiny crawling insect without wings that lives in the cat’s fur and bites at the skin.
The cat louse feeds on the cat’s dandruff, oil secretions from the skin, skin debris, dried blood, and fur.
What do they look like?
These little external parasites which can affect your cat or dog have tiny claws that allow them to crawl around in fur and attach to the hair shaft. The females lay their eggs in the fur in a glue substance that keeps them firmly attached to the hair and difficult to remove. These nits are often visible with the naked eye if you look closely.
Baby lice, meanwhile, look like tiny little white or translucent oval-shaped flakes.
- Adults (1 to 2.5 mm in length) are yellowish to tan with dark markings.
- The head of a chewing louse is wider than their thorax due to huge mouthparts adapted for grasping the hair shafts of the host.
- The head of T. canis has thick, short antennae consisting of 3 segments.
- The head of F. subrostratus also has a characteristic triangular front end.
- In the canine sucking louse (L. setosus), the head is narrower than the thorax due to needle-like mouthparts adapted for sucking blood and tissue fluids. The antennae are short, stout, three-segmented, and fully exposed. Each leg has only one claw. The abdomen is oval and has six pairs of spiracles on the lateral edges of each abdominal segment.
- Eggs (nits) have visible windows when looked at under the microscope, and are glued to the hair shafts.
What is the lifecycle?
The sucking and chewing lice both complete their full 21-day life cycle on the cat or dog. Lice eggs, also called nits, attach to the hair shaft and look like firmly attached white flakes. Once the eggs hatch, the louse nymph emerges and goes through 3 moults to reach the adult stage. The chewing lice nymph eat skin secretions, dried blood, debris, and fur. Sucking lice nymph eat fresh blood and tissue fluids.
There are three nymphal stages of increasing size. The nymphs are smaller than adults but look like an adult. Usually, lice are transmitted by direct host contact. Lice dropped or pulled from the host die in a few days, and few, if any, nits develop after being removed from the host.
Nymphs and adults use their claws and mouthparts to attach to the host.
What are the symptoms?
If your dog or cat has lice, they may have some of the following symptoms:
- Itchy skin
- Dry skin, like dandruff
- Visible lice- may seem them moving
- Visible lice eggs- like small while dots on the fur
- Fur loss
- Pale gums, this could be due to anaemia in young or weak animals
How will they be diagnosed?
Your vet may recommend skin tests which can look for parasites using a microscope if they suspect lice in your cat or dog. The adult louse is a flat, wingless, six-legged crawling insect that is tan or light brown in colour.
To closely identify a louse, the vet may get a piece of clear tape can be used to collect it and then it can be examined under a microscope. Another way to collect the lice and nits is to use a fine-tooth comb to gather them and then stick them to the clear tape for examination under the microscope.
What is the treatment?
If your dog has been diagnosed with lice, they will need the following treatments:
A product to kill the lice on your dog
- Often a ‘spot-on’ or shampoo – your vet or SQP will be able to advise if there is a product licensed for the type of louse your pet has, and if not, a vet will be able to prescribe a medication on the Cascade.
- You will also need to treat any other pets that are in regular, close contact.
- Keep your dog or cat away from other pets until they have recovered.
A product to kill any lice/eggs in your home may also be recommended, this is because lice eggs can survive in the environment for two or three weeks after they have been laid. It is also advisable to treat pet bedding, brushes, coats and the household, again this is because eggs can continue to hatch in the environment for two or three weeks after they have been laid.
To prevent reinfection, throw away or clean any place where your pet spends time, this could be anywhere in the home! Carpets, floors, rugs, furniture and outdoor surfaces should be cleaned thoroughly. Throw away or wash all pet bedding. Lice survive only 3-7 days off the host, so items that cannot be washed easily can be packed in sealed plastic bags for 4-6 weeks (allowing time for all eggs to hatch and die). Clean all grooming brushes, combs, crates, leads and collars with a disinfectant that is suitable for pets.
Other treatments may include for like for other skin problems such as wounds or infected skin. Bacterial infections and scratch wounds are common with louse infestations. If these conditions are present, your vet may prescribe an antibiotic or other medication.
A veterinary surgeon may also want to treat for anaemia as in area cases where the louse infestation is quite high and the cat or dog is immunocompromised, the vet may need to treat.
It’s important to follow your vet’s advice in regard to lice treatment. It is also possible that the cat or dog could have returning symptoms for a few weeks after treatment. It is important to finish the full course of treatment to make sure the lice don’t return.
If a cat or dog is heavily matted or has long hair, your veterinarian may recommend that you clip its fur to help with the treatment.
What else can I do to help the infestation?
In addition to killing the lice on your cat or dog, you will want to be sure that lice are not infesting their bedding, collar, grooming tools (including bushes or combs), and other similar objects in your cat or dog’s environment. Bedding should be washed frequently in hot, soapy water or treated with an appropriate spray until the infestation is controlled.
It is important to keep the pet’s environment clean in order to prevent another infestation. It is also important to keep the pet on regular flea and tick preventatives as most of these products will prevent infestations of other topical parasites including lice as well as various types of mites.
Can lice be passed to humans?
Lice are a host-specific parasites. If you have both dogs and cats in your home, you don’t need to worry about the lice from your dog or cat jumping to the other one either. Both species can get lice, but they are species-specific pests. Cat lice only affect cats, dog lice only affect dogs, and human lice only affects humans.
If you are worried at all about lice, other parasites or if you are worried about your pet’s coat then it is advisable to seek veterinary advice for further information and guidance on the next steps to help with the problem.
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