Pet to People Worms

by Dr. Howard A. Mintzer

We are often asked whether people can get worms from their pets. The answer is....yes. And the problem is more common and can be more dangerous than you think!

What Kind of Worms Do Pets Carry and What Diseases do they Cause in Humans?

The most common worms that can be transmitted from dogs and cats to people all have fancy scientific names like Toxocara cati and Diplydium caninum but you can just remember them as roundworms, hookworms and tapeworms.

Tapeworms that we catch live in our intestines, eat our food and pass little white rice-like segments out of our rear end. As unattractive as it is to see one of these worms squiggling out of the hind end of your cat, it is much more disgusting to find it in your child's diaper! Hookworms burrow under the skin and cause itchy rashes and a disease unappetizingly called "creeping eruptions". The most dangerous of these parasites is the roundworm. Roundworms cause "Visceral Larval Migrans" a condition in which immature roundworms (larvae) migrate through the body. Ten thousand cases of VLM are diagnosed in the United States each year. Most of the time the condition causes little if any illness. However, in approximately 750 cases a year the parasite migrates through a person's brain or eyes causing brain damage or blindness.

How do Dogs and Cats Get These Worms?

Puppies and kittens get roundworms and hookworms from their mother before birth through the placenta or soon after birth through mother's milk. Almost all puppies and kittens have worms by the time they are 2 weeks old. Adult dogs and cats get roundworms, hookworms and tapeworms when they eat other wild animals (mice, rabbits, squirrels, etc.) or when they step in an area contaminated with worm eggs. The worms enter their bodies when they lick their feet off to clean themselves. Tapeworms are more commonly acquired when your dog, cat, puppy or kitten eats a flea (within which the baby tapeworm hides) while he is cleaning his skin.

How do People Get These Worms?

Children are the main "people" who get worms although adults are also at risk. Children get tapeworms when they kiss their pets and accidentally swallow a flea. Hookworms can burrow through the skin. Children who walk barefoot or sunbathers who lie on ground that is infested with hookworm eggs acquire these parasites directly through their skin. Roundworm infection occurs by eating the actual worm eggs. Children who make mud pies, get their hands dirty in contaminated soil or crawl over and play in a litter box and then put their hands into their mouths become infected.

How to Prevent Your Pet From Infecting You

Because puppies and kittens are the major source of worm eggs in the home environment they should be dewormed every 2 weeks from the age of 2 weeks until they are 12 weeks old. After the last deworming they should be retested to make sure that they are free of worms. Deworming is not like giving a vaccine, it doesn't prevent your pet from acquiring worms in the future. It only treats the worms your pet has now. Since pets can continually acquire worms throughout their lives they need to be tested for worms and if needed, dewormed on a yearly basis. Even strictly indoor cats can get worms by eating the occasional mouse that comes inside or the little bug that scampers across the floor and is gulped down by your cat. Since tapeworms are transmitted to your pets and yourselves by fleas, strict flea control is essential.

How to Prevent the Environment From Infecting You