Hookworms are tiny parasitic worms that typically only grow to about an eighth of an inch in size. They get their name from the distinctive bent that appears on one end of their body.

Hookworms start out their journey by penetrating the host, then traveling up the veins to the heart and then the lungs. Once in the lungs, they dig their way through the alveoli walls, which causes the host to cough. At this point the hookworms are usually swallowed again. They travel down to the stomach, then reach their final destination in the small intestine, where they attach themselves to the lining with structures similar to teeth. Now securely attached, hookworms can then feed off your dog indefinitely while causing serious damage to the walls of his intestines.

Once established, hookworms can corner a great deal of your dog’s blood flow, eventually leading to life-threatening blood loss, anemia and hemorrhaging. In addition, these nasty little creatures secrete an anticoagulant substance that makes feeding even easier for them, but also makes matters worse for your dog.

How does your dog get hookworm? There’s a variety of ways, since hookworms are so clever about finding new hosts. For one thing, pregnancy activates previously latent hookworm infestations in many bitches. As a result, many puppies are born with hookworm, and those who aren’t infected in utero frequently become infected shortly afterward from their mother’s milk. Treating the mother effectively is difficult, and requires almost a daily deworming at the end of her term, so many breeders simply treat the puppies instead at 2, 4, 8, and 12 weeks of age.

But you don’t have to be a puppy to pick up hookworm. Hookworm transfers itself to adult dogs in a variety of ways. For one, the larvae can pass directly through the pads of your dog’s feet or even his belly, if he lies down in infected soil.

Hookworm also commonly finds its way in through an adult dog who inadvertently licks infected soil in the process of cleaning himself.

How can you tell if your dog or puppy has hookworm? Common symptoms include emaciation, diarrhea, anemia, listlessness, inflamed “lines” on the skin that appear swollen, and bloody stool.

It’s easy to test your dog for hookworm. Although the worms themselves tend to stay in the intestines, the distinctive hookworm eggs are commonly found in the feces. Treating your dog for hookworm is also a relatively straightforward matter at the vets, and may involve tablets or injections. Treating for complications caused by a long-lasting hookworm problem is a little more complicated. In this case, your vet will usually suggest a treatment plan for your dog’s malnutrition or anemia.

When your dog tests positive for hookworm, your vet will probably recommend a series of follow-up appointments to make sure the cycle’s been broken.

One possibility for discouraging a replay of hookworm is to treat the soil in your yard, killing hookworm larvae at the source (although this method can kill off a number of beneficial organisms as well).

To keep a formerly-infected dog hookworm free, make sure you remove all waste products from your yard or anywhere else your dog roams. This is an important step for people as well as your dog, since hookworm is easily communicable to humans who walk on infected soil with bare feet.