Roundworms, Hookworms, and Whipworms all belong to the same family of parasitic nematodes, a type of worm that latches on to the small intestine, laying microscopic eggs in the feces.  The only way to properly diagnose a dog or cat for these types parasites is to do a “fecal test” and submit a small sample of your pet’s feces to a veterinarian for testing. 

Keep in mind, though, that some parasites lay eggs in cycles and regular fecal tests may not detect all of the parasites in your dog.  For this reason, the Center for Disease Control recommends annual dewormers for adult dogs and a cycle of dewormers every two to three weeks in puppies and kittens. 

You may never see adult parasites in your animal’s feces, but your pet may still display symptoms of worms.  Puppies often have worms and may have a distended abdomen, or pot-bellied appearance as a result.  Adult dogs with infestations of intestinal parasites may have vomiting, diarrhea, or increased appetite with extreme weight loss.  Some animals may be lethargic and show symptoms of illness as well. 

If left untreated, worms can cause severe diarrhea and even death in some animals, especially puppies and kittens.  Roundworms, Hookworms and Whipworms all live in the environment and your pet can contract these parasites when he or she goes outside.  You and your family can also be at risk if feces is not regularly removed from the environment. 

Continue to the next page for more information on each specific parasite

Roundworms are the most common type of intestinal parasite found in puppies and, when passed, resemble cooked spaghetti.  Adult worms, however, rarely leave the animal’s body unless they are dead.  Because of this, your pet may have roundworms, but you may never see them. 

Roundworms are picked up through your animal’s environment or from the mother.  Most puppies and kittens are born with worms, having been infested from the mother in the womb.  If they are not born with worms, they are very likely to pick them up from their environment and can even become infested through the mother’s milk. 

Older animals usually contract roundworms from areas where other animals have defecated.  Adult worms lay tiny eggs in the intestines that are then passed out with the feces.  These eggs then stay in the environment until either the area is cleaned or another animal picks them up.  Although eggs are passed through feces, they can easily rub off onto grass or other objects and eventually onto your dog’s toys or twigs. 

Because these eggs can pass so easily in the environment, the CDC recommends that all dogs be dewormed annually.  These parasites can and will infect humans.  Children are especially at risk since they are less likely to wash or discard dropped food or wash their hands after playing outside. 

Besides causing distended abdomens, roundworms can cause eventual diarrhea, lethargy, and even death in very young animals. 

Hookworms, although not the most common parasite in dogs, have a tendency to cause severe symptoms in their host.  Like roundworms, adult hookworms lay microscopic eggs in the intestine that are passed out of the body with the feces.  Adult worms are not likely to appear since they stay attached to the intestine for most of their life.  In order to properly diagnose an animal for hookworms, a veterinarian must look at the feces under a microscope in order to find the eggs.

Hookworms can cause a distended abdomen, but are much more likely to cause diarrhea first.  In fact, hookworms can cause lethargy (tiredness and inactivity), lack of appetite, and diarrhea, many of the same symptoms as parvovirus.  Large infestations of hookworms have the ability to cause the same type of bloody diarrhea associated with parvo.  These types of infestations are sometimes mistaken for parvo which is why its essential to have an animal tested for both parvo and hookworms if he or she shows any of the above symptoms. 

Hookworms are rather simple to treat (unlike parvo) and animals diagnosed with these worms usually receive a series of doses of deworming medication in order to rid them of the parasite. 

Hookworms can kill puppies if they are left untreated and can be transmitted to humans through the environment.  Pick up feces regularly and keep areas clean.  Since hookworms can infect their host via the mouth as well as the skin, any areas that have been used by an infected animal should be thoroughly cleaned and treated. 

Whipworms also live in the intestine and also lay microscopic eggs that are passed in the feces.  Like hookworms, whipworms can cause diarrhea in their hosts, but are less likely to cause the same severe symptoms present with hookworms. 

Unlike their relatives, whipworms do not always lay eggs and are therefore less likely to be properly diagnosed.  Fecal tests can come up negative for whipworms even though your pet may be infected with these parasites.  Because of this, all dogs should be dewormed regularly for intestinal parasites and even more frequently as puppies.  Severely infected individuals can have more serious symptoms including bloody diarrhea and even death.

Like the other parasites, dogs can be infected through ingesting eggs in their environment, usually through items dropped on the grass or soil.  Like other parasites, these can also infect humans so be sure to clean up all areas with feces. 

Whipworms can be easily treated by a veterinarian.