Can dogs get head lice and transfer them to humans (or vice versa)?

Question

If we have head lice, can we transmit them to our dogs, or can they get them and transfer them to us?

Answer 1

The short answer is no, although dogs and humans can get lice, there are many different kinds that are specialized for different species; even within species there can be specific lice that are not transferable between areas (for example, there are several different types of lice that specifically inhabit different parts of the human body - the head OR pubic area, not both). This has to do with the actual width of the hair and the morphology of the lice species, which in this case is not related to the question.

From Veterinary Medicine:

Lice are species-specific, meaning that there is a different species of lice for each animal species that they depend on. Human lice need human blood to survive, dog lice need dog blood, and so on. Therefore, if your child comes home from school with a diagnosis of head lice, your dog, cat, or other pets in the household are not at risk from catching the lice or hatching eggs. Conversely, while not as common in dogs and cats, the species of lice that live on dogs and cats are not able to live on humans.

While not an immediate threat to health, human head lice is very contagious and is not an indicator of poor personal hygiene. Lice are not as common in healthy dogs and cats as they are in humans. Poor nutrition, poor overall health, and very old or young dogs and cats are most at risk for lice infestation.

Furthermore, lice are not one of the more common parasites found in dogs and other household pets, such as cats:

Yes, dogs and cats do sometimes get lice, although lice are not one of the more common parasites diagnosed. They are most common in animals that live in poor conditions without proper sanitation. Dogs can get two different types of lice: Trichodectes canis and Linognathus setosus. Cats get only one type: Felicola subrostrata.