Lice, while not fun to think about, are easy to identify. They are wingless, flat, six-legged insects that attach to a host's hair shafts. Untreated lice infestations can lead to skin issues and bald patches caused by excessive scratching, and lice have also been known to transmit diseases. Lice feed off the skin or blood of their hosts; in cases of severe infestation of small puppies, blood loss from lice can lead to shock or even death. Infestations are relatively rare among dogs in the United States, though they are common among feral dogs. However, lice can be avoided and treated.
What Are Lice?
Lice (singular louse) are parasites that can infest any animal that has a coat of hair. Lice are host-specific, meaning that each species of animal is only infected by their own special species of lice. For example, if a stray louse from a deer finds its way onto a dog or even a person, it will not remain there.
Unlike ticks, which are actually arachnids (related to spiders), lice are light in color and oval in shape. Lice glue their eggs on the hair shaft close to the skin, and the resulting offspring (called nits) look very much like dandruff. Though dogs do sometimes get lice, lice are not a common parasite in well cared for pets. Lice are most common in animals living in inadequate conditions without proper sanitation.
Dogs can get two different types of lice: Trichodectes canis are skin-biting lice, and Linognathus setosus are blood-sucking lice. Bloodsucking lice do what their name implies: pierce the skin to ingest the dog's blood. The lice that bite at a dog's dead skin are irritating, causing dogs to scratch. Both types of dog lice also carry other diseases such as tapeworms.
Symptoms of Lice in Dogs
The most common symptom of a lice infestation is extreme itchiness. Most dogs infested with lice suffer sudden fits of scratching, sometimes to the point of breaking the skin and causing bleeding. With both species of lice, untreated lice can cause fur loss from repeated scratching, but skin-biting lice are the more irritating parasite.
Upon close inspection, it is possible to see lice among the dog's hairs. Lice are light-colored and slow-moving. Fleas, by contrast, are dark and fast-moving, while ticks are dark and immobile. Because lice lay their eggs on the shafts of pet hairs, it's also possible to see their empty eggshells which look very much like dandruff. Any white flakes that are sticky and hard to remove from the hair are almost certainly unhatched lice eggs.
Causes of Lice
Lice are transmitted when two animals are close enough to one another for the parasites to get brushed onto another host. Shared grooming tools also make for easy transfer. Transmission can occur in:
- Pet stores
- Pet adoption centers
- Pet daycares
- Pet shows
- Dog parks
While poor sanitary conditions and crowding lend themselves to lice infestations, lice will take advantage of any social setting for dogs, such as agility events or even group walks.
If you notice your dog scratching and suspect lice, take it to a veterinarian to be sure it's not something more serious. Lice are sometimes confused with fleas that require slightly different treatment. Your veterinarian should be able to recommend an over-the-counter spray, shampoo, or spot treatment for your pet's lice.
Many products kill and repel lice including shampoos containing pyrethrins or organophosphates. On-the-spot insecticides like Advantage (imidacloprid) and Revolution (selamectin) can also be effective against dog lice.
It's important to note, however, that while permethrin-containing products can help treat dogs, permethrin is toxic to cats. Thus, if your home includes both dogs and cats, be sure to let your vet know that you should avoid treatments containing permethrin.
While pharmaceuticals are very effective, another safe, non-toxic option is a lime-sulfur dip. While it may have a few side effects (such as the smell of sulfur and a short-term yellow tinge to your pet's fur), it works quite well. Dips should be repeated each week for up to six weeks.
It's also helpful to use a fine-toothed lice comb or flea comb to remove dead lice and sticky nits from your dog's fur. Sanitize combs after each use. Dispose of any bedding, brushes, or cloth toys that a pet infected with lice has used, and if possible, have any furniture they use frequently, such as chairs or rugs steam cleaned.
If you have a dog with lice and more than one animal lives in your home, it's best to keep the infected animal away from the others during the course of treatment. Still, you'll likely end up treating all of your dogs since lice spread fairly easily. During treatment (about four to six weeks), keep your dogs away from all other dogs; that means avoiding pet shows, agility events, pet daycares, and other communal pet settings.
How to Prevent Lice
There is no way to absolutely prevent lice infections, but some steps may reduce the likelihood of a problem. Keep your dogs in clean locations, and make sure bedding is washed and/or changed regularly. Avoid allowing skin-to-skin contact with any scratching dogs from outside your home.
If you do take your dog to shows, competition events, daycares, or obedience schools, check the location ahead of time to be sure it's clean and well managed. If you take your dog to a groomer, inquire about how the grooming equipment is cleaned and sanitized in between clients. Consider requesting an on-the-spot treatment which can reduce the likelihood of lice infestations.
Are Dog Lice Contagious to Humans?
Head lice are common parasites, especially for school-aged children. Often, the family pet gets blamed for the infestation. But your family cannot get lice from your family dog.
People do not get lice from dogs; nor do dogs get lice from people. Lice are species-specific parasites. Human lice need human blood to survive; dog lice need dog blood and so on.