What Is the Difference Between Dog Fleas & Head Lice?

Dog fleas and head lice are both wingless insects that cause a major hassle for people dealing with an infestation. The similarities of the two species end with them being insects. Head lice are only found in humans, while fleas are commonly found on dogs and can also bite humans. The most common type of flea found on dogs is actually called the cat flea and it can cause a lot of problems for pets and humans.

  1. Look, Size and Eggs

    • Adult head lice are never bigger than a sesame seed and are grayish-white or tan in color. Both fleas and lice lay oval shaped eggs but flea eggs are white in color while lice eggs are tan or coffee colored. It is more common to notice a lice outbreak by identifying the eggs, which will look like dandruff but cannot be removed by brushing. According to EcoSmart.com, fleas are also small in size, ranging from 1/16 to 1/8 of an inch long and are dark reddish brown in color.

    How They Spread

    • Head lice are not spread from animal to humans or from humans to animals; they are spread from human to human by contact with infested areas or people. Physical contact with a lice infested person or object and using clothing, towels, hair pieces and hair brushes can cause head lice to spread. Dog fleas can be found on dogs, cats and many other types of animals. They can spread from one type of animal to another species and also can hide in home furnishings, carpets and fabrics waiting for an opportunity to feed. Fleas can also spread from pets to humans or can go from humans to pets.

    Effects on Humans and Pets

    • Head lice are not found on dogs or pets, meaning no harmful side effects can occur from head lice to pets. On humans, the biggest problem that head lice will cause is a red, itchy scalp and sores or skin infections can occur from itching. Lice are not dangerous to humans, notes Health Promotion and Education. Fleas on dogs will lead to many sore spots on animals. Fleas can bite humans spreading diseases and if accidentally ingested, they can spread tapeworm. Fleas are more harmful and have a greater potential for spreading diseases and causing problems for pets and humans than head lice.

    Life Span and Amount of Hosts

    • Lice can live up to 30 days on a person's head. Head lice need human blood to feed on to survive and if they fall off a person's head, they can live for up to two days. They do not jump around from human to human and cannot live on dogs. Lice will have one host for its adult life. Fleas can move from different hosts, going from dogs to humans or vice versa. They can also live between 2 to 14 days without a host to feed on. The larvae of fleas can live for months and while adult fleas do not have a long lifespan, their larvae can continue infestations long after adult fleas have perished.