Causes of Hookworms in Dogs and Cats

Hookworms are a parasite of the intestinal tract that can infect dogs, cats, humans, and other animals. Pets and people can get hookworms from ingestion, but, surprisingly, they can travel through the skin too, taking a long trek to your pet’s intestines.

Life Cycle

It’s hard to understand the causes of hookworms without learning their lifecycle first. Adult hookworms live in the intestinal tract of their hosts, where they produce eggs throughout their lives. They shed these eggs, which get passed out into your pet’s feces, where they will later hatch in the outside world. After about seven days, hookworms develop into third stage larvae. In this stage they can live for about one to two months, waiting to infect you or your pet via ingestion or skin contact. If they find their way into your pet’s body, they’ll mature into adult hookworms and continue the lifecycle.

Infecting through the Skin

Larvae need at least five to ten minutes of contact between the host’s skin and contaminated soil to successfully infect you or your pet. Most pets are infected through the pads of their paws, whereas humans can be infected anywhere where skin touches contaminated soil. Once hookworms burrow into your pet’s dermis, they travel through vessels and veins until they reach the lungs.

Once in the lungs, your dog or cat can inadvertently swallow hookworms, where they find their home in your pet’s intestinal tract. In other cases, an adult animal’s body will be able to block the spread of the infection, and the hookworms will live dormant in the lungs. While this kind of infection shows no symptoms, dormant hookworms living in the lungs can pass to puppies if an infected dog gets pregnant.

Infecting during Pregnancy

Dogs, who are more susceptible to hookworms than cats, can pass this parasite from mother to puppy in utero. Additionally, mothers can pass hookworm larvae to their puppies through breast milk. Because the side effects are much more dangerous for young dogs, all mothers should be screened for hookworms before breeding. Scientists have still not determined if hookworms can be passed from mothers to kittens, but good practice includes screening for cats before breeding.

Infection via Ingestion

If your pet eats infected soil, food that has touched infected soil, or infected feces, hookworm larvae can enter their digestive system. In this case, the hookworm larvae will travel directly into the intestinal tract, where they will mature into adult hookworms. In some cases, cats and dogs can get hookworms from eating infected cockroaches or rodents. Controlling your dog’s access to the spot where they eliminate, and frequent cleaning of your cat’s litter box can help combat infection.

Human Hookworm Infection

Humans rarely get hookworm infections, when they do they are mostly affected through the skin. Similar to animal infections, hookworms can penetrate the skin and cause an itchy infection called creeping eruption. These infections, while uncomfortable, generally clear up of their own accord. Only in very rare instances can hookworms travel from the skin into a human intestinal tract as they do in animals.

This information is for informational purposes only and is not meant as a substitute for the professional advice of, or diagnosis or treatment by, your veterinarian with respect to your pet. It has, however, been verified by a licensed veterinarian for accuracy.