Lice are tiny, wingless insects that like to reside in and infest the hair or feathers of animals and humans. They exist in two distinct groups. Chewing or biting lice (belonging to the order Mallophaga) attack mammals and birds, getting their sustenance from the host’s secretions and skin waste. Blood-sucking lice (of the order Anoplura) live on and feed off mammals alone. Lice tend to be specific to a species, i.e. they do not usually move from a particular species of animal to another.
The eggs of lice, also known as nits, are glued by the female to the host’s hairs right next to the skin. Nits are colourless and oval in shape. After the eggs hatch, there is a nymph phase that the lice have to undergo prior to becoming adults. Removal of the nits cannot be achieved even through washing and using ordinary shampoo. During this intermediate stage, the nymph resembles the mature adult lice, though it is smaller in size. The lifecycle of most lice, from nit to a fully developed adult, usually takes about 3 to 4 weeks. However, this time frame may depend on the species.
There are certain signs that are glaring indications of a lice-infested dog. These include biting, scratching, and rubbing of infested areas. The affected dog will develop a coarse, dry coat, and in cases of heavy infestation, the hair may also be dishevelled. Unhealthy dogs make good candidates for severe infestation.
There are 2 species of lice that a dog can be infested with; the blood-sucking Linognathus setosus and the biting Heterodoxus spiniger. Blood-sucking lice create tiny wounds that can get infected. They tend to be slow in their movements, and are often discovered with their mouth-parts inserted into the skin.
The biting louse is not commonly found in North America. It usually acts as a transitional host for intestinal tapeworms. The biting lice are more active and faster moving than the blood-sucking variety, and can be seen moving when the hair is parted.
A fine-toothed comb cannot be effectively used to remove nits, and this process doesn’t kill lice that have already hatched. Dips, dusts, sprays, or washes that eliminate lice can be used to treat affected cats, dogs, and other pets. Your veterinarian should be able to prescribe a suitable control product and give instructions for its use on your pet.
Although the lice that have been removed from the body of the host will die after a few days, the eggs may go on to hatch 2 to 3 weeks later. For this reason, lice control treatments should be continual 7 to 10 days following the initial treatment. You should inspect your pet’s coat carefully every day for at least a fortnight after you see the final louse. Any lice (dead or alive) that have been removed from your pet should be carefully collected and gotten rid of quickly in a sealed container (for example a zip-lock plastic bag).
If a dog is severely infested by lice, it may scratch itself until it breaks the skin. This may lead to wounds and bacterial infections. Such situations require an antibiotic or other medication which your veterinarian may prescribe.
Apart from killing the lice, it is also important to ensure that your dog’s collar, bedding, grooming tools, and other similar objects in the vicinity are not infested by lice. These objects should be carefully cleaned and checked in order to ensure your pet doesn’t suffer from the irritation brought by lice.
Humans are not common targets for the lice that infest cats, dogs, and other pets. Consequently, while it is advisable to take care when dealing with lice that has infected your pet, it should be understood that humans are highly unlikely to get lice from their pets.