Roundworms in Dogs and Cats

Roundworms, also known as ascarids, are the most common type of parasite seen in dogs, cats, puppies and kittens. Roundworms have been known to infect people, particularly children. In children, potential complications associated with roundworm infection include blindness, seizures and other maladies. Therefore, roundworms have a public health significance and controlling them for the family pet should not be ignored.

What are Roundworms?

Roundworms are intestinal parasites, meaning that they are worms which infect the intestinal tract of the dog and cat. Roundworms can infect other species as well, such as raccoons.

What Symptoms can a Roundworm Infection Cause in Dogs and Cats?

Younger puppies and kittens are most often diagnosed with roundworms, but roundworms can infect dogs and cats of any age. The most common symptoms seen with roundworms are:

• diarrhea
• vomiting
• weight loss or inability to gain weight normally
• a pot-bellied or swollen appearance to the abdomen
• coughing

In severe cases, roundworms can cause dehydration through fluid loss resulting from diarrhea and vomiting.

However, often there are no symptoms at all for the infected cat or dog and the pet seems perfectly normal and healthy.

How Does a Dog or Cat Become Infected with Roundworms?

In puppies and kittens, the most common route of infection is from the mother. Roundworms can be passed to kittens and puppies before birth, so many kittens and puppies are born with roundworms. Roundworms also can be passed from the mother to babies through the milk as the puppies or kittens are nursing.

In more mature dogs and cats, the usual means of infection is through ingestion of an infected fecal sample or by ingesting prey animals (i.e. hunting and killing smaller animals).

How are Roundworms Recognized in Dogs and Cats?

Roundworms can sometimes be seen in the feces of infected dogs or cats (or puppies and kittens). When seen in this fashion, the roundworm will appear as a long, white slender worm. Roundworms are often described as looking like spaghetti.

However, not seeing adult roundworms in the feces does not guarantee that a dog or cat does not have roundworms. A more reliable means of diagnosis is to have your pet’s feces analyzed by your veterinarian. Your veterinarian will examine your pet’s feces under a microscope, after using special techniques to concentrate any worm eggs present in the feces into a small, confined location. This type of fecal analysis looks for roundworm eggs in the feces. Roundworm eggs are too small to be seen with the naked eye but can easily be identified microscopically.

It is advisable to have your pet’s feces analyzed periodically. Usually, a fecal test every six to twelve months is sufficient after one year of age. More frequent fecal checks are advised for puppies and kittens under one year of age.

How are Roundworms in Dogs and Cats Treated?

There are numerous medications available to kill and control roundworms in dogs and cats. Some of the commonly used medications include:

• pyrantel, available as Strongid T and other brand names
• fenbendazole, available as Panacur
• piperazine

In addition, many of the monthly heartworm prevention medications are also effective in controlling roundworms in dogs and cats when given every month as recommended.

For puppies and kittens, routine strategic dewormings done at a very young age, even as early as 2 weeks of age, are recommended to help decrease the potential for spread of roundworms to people within the household. This is recommended because of the fact that most puppies and kittens are either born with roundworms or acquire them at a very young age.

The roundworm life cycle is roughly 21 days in length, so a second deworming is advisable three to four weeks following the first. Many veterinarians recommend a series of three dewormings given three to four weeks apart for puppies and kittens and for adult dogs and cats infected with roundworms.