Hookworm in Dogs

Hookworms are nasty, so it’s vital that you know what “hookworm” in dogs is and how to recognize the signs of hookworm in dogs.


Hookworm in dogs is an intestinal parasite. Your dog can be infected by eating contaminated debris, intermediate hosts, and even when larvae penetrate the dog’s skin. Puppies can be infected with hookworm via the milk of an infected mom.

Adult hookworms can live for two years inside your dog by sucking his blood. The primary species of hookworm in dogs is Ancylostoma canium, considered the most prevalent and important intestinal parasite in dogs.

The hookworm is a nasty parasite. The worms (larval and adult) attach or “hook” into the intestinal wall. Once attached, they suck blood out of the tissues. They secrete anticoagulants to stop the blood from clotting. If the hookworms move on to a new site, they leave ulcerated areas behind.

An important note is that hookworms are a zoonoses, a disease spread between animals and humans. This means you can be infected with hookworms, too. Hookworms are an important cause of cutaneous larva migrans, an infectious syndrome in people with red, twisty lesions on the feet and arms where larvae have borrowed in.

Hookworm Symptoms in Dogs

The signs of hookworms in dogs are worst in puppies, especially young puppies who got hookworm from nursing. These puppies can bleed out, becoming so anemic from a heavy load of hookworms that they die. Slightly older puppies also may show respiratory signs as immature hookworm larvae migrate through the lungs on their way to the small intestines.

Symptoms of hookworms in older dogs are less obvious, as older dogs have a bit more resistance than puppies. Healthy dogs may not show many symptoms, but they can pass hookworm eggs in their stools, which can be picked up by other dogs.

Dogs who got hookworms from infected larvae traveling through the skin of their feet will have infected and sore paws. The skin between toes will be moist, itchy, and painful.

Hookworms May Cause Black Stools in Dogs

Senior dogs, dogs with a chronic illness, and dogs who are stressed will show more symptoms. These dogs will lose weight, may stop eating, and become weak from malnutrition and anemia. Often, dogs infested with hookworms will have black stools due to digested blood.

Diagnosing Hookworm in Dogs

Hookworms are diagnosed using a fecal sample to look for eggs or antigens. Treatment must be repeated until negative fecal results are achieved. Luckily, many oral medications that kill hookworms include many monthly heartworm medications such as Heartgard, Advantage Multi, and Interceptor Plus.

Panacur C used alone is also generally effective. Unfortunately, some resistant strains of hookworm are being identified and may require a combination of drugs. This makes it extremely important that you follow your deworming with fecal checks to be sure that treatment was effective.

Reinfection of Hookworms in Dogs

This parasite can survive for months outside, although freezing temperatures kill off many larvae. It can also survive encysted in your dog’s tissues, only becoming reactivated with pregnancy or stress.

Prevention is best done via regular poop patrol of your yard and avoiding places with large numbers of dogs who are not tested for parasites (like unregulated dog parks with high traffic). Luckily, monthly heartworm medications will stop many hookworm infections before they get well established.