Hookworms are intestinal parasites that get their name from the hook-like mouthparts they use to anchor themselves to the lining of the intestinal wall. They are so small that it is very difficult to see them with the naked eye. Hookworms ingest large amounts of blood from tiny blood vessels in the intestinal wall.
Hookworms are more common in warm, moist environments.
How do dogs get hookworms?
Dogs may become infected with hookworms by one or all of four of the following:
- oral ingestion
- through the skin
- through the mother’s placenta before birth (in utero)
- through the mother’s milk
Female hookworms pass hundreds of microscopic eggs in the feces of infected dogs. The larvae hatch from the eggs and can remain infective in the soil for weeks to months. A dog may become infected when it inadvertently swallows hookworm larvae, often by grooming its feet, from sniffing feces, or contaminated soil.
The common signs of hookworm infection in dogs:
- Intestinal distress
- Significant weight loss
- Bloody diarrhea
- Dull and dry coat
- Skin irritation and itching, especially of the paws
- In severe cases, coughing
- In puppies – failure to grow properly
Hookworm infection is diagnosed using a technique called fecal flotation. The stool is mixed with a solution that causes the parasite eggs to float to the top of the solution and adhere to a glass slide. Because many eggs are produced daily and have a unique appearance, hookworm infections are easily detected.
How is a hookworm infection treated?
There are several effective drugs, called anthelmintics, that will eliminate hookworms. Most are given orally and have few, if any, side effects.
However, these drugs only kill adult hookworms. Because of this, it is necessary to treat an infected dog again in two to three weeks to kill any new adult worms that were larvae at the time of the first treatment.
In rare cases, a blood transfusion may be necessary for dogs with severe anemia.
Are canine hookworms infectious to people?
Adult hookworms do not infect humans; however, the larvae can burrow into human skin usually through bare feet. This causes itching; however, the worms do not mature into adults and will die within several weeks.
More dangerous is the condition in which hookworm larvae migrate throughout the human body, damaging the eyes and internal organs. This is called visceral larval migrans. Direct contact of human skin to moist, hookworm-infested soil is required. Fortunately, this is extremely rare if normal hygiene practices are observed.
How can I keep myself and my dog safe?
- All puppies should be treated with a veterinary-approved anthelmintic product at two to three weeks of age. In addition, prompt deworming should be given if the parasites are detected. Periodic deworming may be appropriate for pets at high risk for infection.
- Prompt disposal of dog feces should occur, especially in yards, playgrounds, and public parks.
- Strict hygiene is important, especially for children. Do not allow children to play in potentially contaminated environments. Frequent hand washing and bathing are essential in preventing human infections.
- Nursing female dogs should be dewormed at the same time their puppies are. Pregnancy and nursing may reactivate a dormant hookworm infection in the female dog, which will then infect her puppies.
- Most heartworm prevention products contain medication to treat hookworm infections. Some of these products kill the adults, while others will also kill larval stages and prevent infestations. We can advise you on the best product for your dog.