Human Head Lice Are Not Spread by Pets
It is a common misconception that pets can bring head lice into a family’s home.
Human head lice are only able to live off of human hosts and pets cannot carry them. Pets can bring in fleas, ticks, and other pests, but head lice are not one of them. Pets also cannot catch head lice from human hosts. The reason for this is the difference in body temperature between humans and animals. The temperature of a human head is the ideal place for head lice to thrive. Because animals like cats and dogs run at a higher temperature, if a louse crawls from a human host to an animal’s fur, the louse cannot survive more than a day. In addition to pets being unable to catch head lice from humans, the same is true for humans when it comes to lice that affect animals.
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. Via vetmedicine.about.com
Using chemical head lice treatments on animals can be extremely harmful to their health. Because human head lice do not pose a threat to pets, do not use head lice treatment on them. If a pet is suspected of having lice it will be specific to that type of animal and it is best to consult a veterinarian for care.
There are over 3,000 species of lice in the world, but a mere 3 of them are considered agents of disease in humans. The rest, however, are typically species-specific; that is, they seem to show a preference for a certain type of host. That means that some species will tend to feed only on humans, some only on cats, others only on dogs, etc. Dogs can get two types of lice, Linognathus setosus and Trichodectes canis. Cats get only one type of lice called Felicola subrostrata. Via petplace.com