to Pet Health Network or

Answers from vets about your pet:

What are Hookworms and Why Should I Care?

Reviewed by Peter Kintzer DVM, DACVIM on Thursday, April 17, 2014
Posted April 18, 2014 in Dog Diseases & Conditions A-Z

Hookworms are a significant parasite of dogs and cats and have very real zoonotic implications.

What are hookworms?
Hookworms are a parasitic nematode (worm) that inhabits the intestinal tract of a host. Hookworms are named for the hook-like mouth parts with which they attach to the lining of the intestine and use to feed on the blood of the host. Hookworms can infect humans (N. americanus and A. duodonale) as well as dogs (Ancylostoma caninum, Ancylostoma braziliense, and Uncinaria stenocephala) and cats (Ancylostoma tubaeforme, Ancylostoma braziliense, Uncinaria stenocephala). They are quite small but can cause heavy infections that result in severe inflammation and blood loss; in some individuals, kittens, and puppies for example, these infections can prove fatal if not treated.

How common are hookworms?
Although more common in warmer coastal regions, hookworms are fairly common in dogs and cats throughout the U.S.  Infection rates range from 1%-35% depending on climate and lifestyle.

How does my dog get them?
Adult worms in the intestine of infected dogs reproduce and pass eggs which become infective in 1-3 weeks.  Dogs and cats can be infected by swallowing the larvae or by nursing from an infected host. Hookworms can also burrow through the skin. 

Dog OutsideWhat are the symptoms of hookworm? 
Hookworms consume blood from the lining of the intestine. An adult hookworm can consume 0.1ml per day and a heavy infection can result in significant anemia, particularly, in very small or very young animals. Blood in feces is not generally seen, but inflammation caused by these parasites can result in diarrhea.

How do I know my dog has hookworms and how do I treat it?
The worms and their eggs themselves are quite small and direct visualization should not be relied on. The best diagnostic is a microscopic examination of the stools following centrifugation. This concentrates the eggs so they can easily be seen under a microscope.

Do hookworms infect people?
Once a common disease, hookworms have all but been eradicated as an internal parasite for humans in North America. However the disease is still rather common in emerging countries. Hookworms commonly enter humans, in particular children, by burrowing through the skin. Additionally, the infective larvae can contaminate food sources and with inadequate preparation be ingested. Children can be exposed while playing in the soil or at a beach where dogs have been allowed to soil and contaminate the sand.  The infective larva burrows

Related symptoms: 

Share This Article

Mike has more than 35 years of experience in companion animal veterinary practice and is a valued member of IDEXX’s Pet Health Network team since 2013.