Lice in Dogs Causes and Treatment

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Dog in grass itching behind its ear
Dog In Grass Itching Behind Its Ear

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 a 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 and Europe. 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 and have been reported in rural areas of South and Central America.

Dogs can get 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.

selective focus photography of short-coated tan dog during daytime
selective focus photography of short-coated tan dog during daytime

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, extreme itch, trauma to skin and infection and extreme discomfort.

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:

  • Kennels
  • Pet stores
  • Pet adoption centers
  • Pet daycares
  • Pet shows
  • Dog parks
man in brown jacket standing beside glass door
man in brown jacket standing beside glass door

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.

Pharmaceutical Treatments

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.

Many products kill and/or repel lice including fipronil, lime sulfur dips, selamectin and more. Discuss which would be the best option for your dog (and remember NEVER to apply a dog flea or tick medication to your cat as cat's are very sensitive to a permethrin type topicals).

At-Home Treatments

grey short coat large dog stands on crest of hill
grey short coat large dog stands on crest of hill

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. Discuss frequency of the dips for lice with your veterinarian.

It can also be helpful to use a gentle shampoo and 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 which can be 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

Year round flea and tick prevention as recommended by your vet may be helpful in preventing lice infection. Discuss this with your veterinarian.

person holding leash of adult gray and white Great dane
person holding leash of adult gray and white Great dane
short-coated brown dog sitting on green grass field
short-coated brown dog sitting on green grass field
selective focus of dalmatian dog
selective focus of dalmatian dog

Lice is very uncommon here in the United States but there are some steps that 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?

Your family cannot get lice from your family dog. Head lice that we see in school aged children are different type of lice. 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.