What are hookworms?
Hookworms are intestinal parasites of dogs and cats. Ancylostoma and Uncinaria are the two most commonly diagnosed subtypes of hookworms. Their name is derived from the hook-like mouthparts they use to attach to the lining of the intestine. They are small parasites, usually only measuring 1/8” long, and are barely visible without a microscope. However, despite their small size, they can be an important cause of illness, especially in puppies and kittens. They can also be dangerous to your family.
How did my dog or cat get hookworms?
Most commonly, puppies get hookworm infections from their mother before birth or through their mother’s milk during nursing. This has not been shown to be a source of infection in kittens. Dogs and cats are typically infected after swallowing hookworm larvae (immature worms) in the environment. The larvae may also enter the body through the skin and migrate to the intestine to mature. Some larvae venture out and migrate to other organs, such as the lungs, before completing their life cycle. Once adult worms reproduce, new eggs are passed in the stool and the life cycle of the parasite is complete.
Hookworm larvae are quite common in the environment, especially in environments contaminated with feces from dogs or cats. Once present, larvae can persist in the soil for months. In addition, hookworms can enter a period of arrested development (hypobiosis) in the body. Months to years later, parasites can become reactivated leading to an active infection. Some breeds of dogs, especially greyhounds, are especially prone to chronic hookworm infestation.
What are the clinical signs?
While these parasites can be asymptomatic in adult dogs and cats, large numbers of worms can lead to life-threatening problems. Blood loss (anemia) is the most significant clinical syndrome associated with hookworm infection. Pale gums, weakness, bloody stool, or dark tarry feces can be indications of a hookworm infection. Weight loss, decreased appetite, vomiting, diarrhea, poor growth, and local skin irritation are other potential clinical signs. While death is rare, it can occur with serious infections, especially in puppies, kittens, or ill animals.
How are hookworms diagnosed?
Hookworms are diagnosed by microscopic examination of your pet’s stool. Since your veterinarian is searching for eggs and shedding of eggs can be intermittent, more than one sample may be necessary to make a diagnosis.
How are hookworms treated?
Fortunately, treatment is safe, simple, and relatively inexpensive. Deworming medications (anthelmintics) are given for 2-3 treatments at 2-3 week intervals. It is important to note that none of these treatments will kill the migrating larvae or immature forms of the parasite, so repeated treatments or administration of a monthly preventative medication is necessary to completely eliminate the infection. In severe cases of anemia, a blood transfusion may be necessary. It is important to recheck a fecal sample after treatment to ensure that the infection has been cleared.
How can I prevent infections?
1) Puppies and kittens should receive deworming medication at a young age. Often, breeders will begin deworming puppies and kittens even before they go to their new homes.
2) Eggs can survive in the environment for years and are highly resistant to most disinfectants and even to harsh environmental conditions. Prompt disposal of all feces is important, especially in yards, playgrounds, and public parks. Litter boxes should be scooped daily and cleaned thoroughly once weekly. A mixture of dilute bleach (1:10 dilution) can be used to clean litter boxes and contaminated toys or kennels. Always wash your hands thoroughly after handling feces or cat litter.
3) For those animals that are exposed to other dogs or cats, monthly preventative therapy with Heartgard Plus (dogs) or Revolution Plus (cats) is necessary to prevent repeated infections. In addition, all pets should have a fecal intestinal parasite examination performed at least 1-2 times per year.
Are hookworms dangerous to humans?
Yes, hookworms can be a health risk for humans. The hookworm larvae can burrow into the skin, causing a disease called cutaneous larval migrans. Itching and a skin rash (also known as ‘ground itch’) characterize this skin infection. Larvae generally remain localized to the skin, but a few intestinal infections have been reported.
Infection in humans requires contact with moist, larvae-infected soil. Infection rarely occurs when good hygiene is practiced. Clean up your pet’s feces daily and wash your hands thoroughly after handling feces or anything potentially contaminated with feces. Children’s sand boxes should be covered when not in use and caution should be exercised when your children are playing in public parks, beaches, or other potentially contaminated areas.
All animals should be on a year round parasite preventative to prevent infection. We offer Heartgard Plus for dogs and Revolution Plus for cats. Protecting your pets will protect your human family!
Content prepared by St. Francis Animal Hospital, 1227 Larpenteur Ave. West, Roseville MN. 55113