Dog Parasites Transmitted to Humans

Some dog parasites can affect dog owners, too. Let's look at some common parasites that can pass between dogs and their owners, along with some ways to help protect yourself from parasite infestation.

Canine External Parasites

The main parasites that affect dogs are fleas, ticks, ringworm and mange. All have health implications for people. Fleas can serve as hosts for tapeworms, which we'll discuss in more detail shortly, and they can also transmit rickettsiosis and bartonellosis. Ticks can carry Lyme disease, Rocky Mountain spotted fever, tick paralysis and tularemia.

Ringworm isn't actually a worm, but rather a fungus that feeds on skin, hair and toenails. Keep children, older people and anyone with a compromised immune system away from a pet with ringworm until the infestation is completely cleared up as these groups are the most likely to contract the fungus from a pet. Sarcoptic mange spreads easily between dogs and between dogs and people, while demodectic mange is not considered contagious.

Many Types of Worms

A variety of worms can make themselves at home in your dog's digestive tract, including roundworms, hookworms, whipworms and tapeworms. Dogs can come into contact with these parasites by eating dirt that is contaminated with parasites or eggs, by licking their paws or fur after coming in contact with parasites or by drinking water that has parasites or eggs in it.

Roundworms: Roundworms are the most common canine intestinal parasite. Many puppies are born with this parasite in their systems. They take up residence in a dog's small intestine and siphon nutrients from his body. In dogs, roundworm infestation can lead to intestinal or respiratory problems, while in people, the worms can cause lung, brain, liver or eye damage. Roundworms can also cause a condition called visceral larva migrans in which immature worms move through a person's body, causing fever, an enlarged liver, anemia or pneumonia.

Hookworms: Hookworms are the second-most-common canine intestinal parasite. They suck blood from a dog's intestines, which can lead to blood loss, malnutrition and weakness in dogs. In people, hookworms can cause intestinal problems or a condition called cutaneous larval migrans in which the worms leave itchy, red trails in the skin as they move under it.

Whipworms: Whipworms also suck blood from a dog's intestine, but they are less likely to cause health problems than hookworms. Canine health problems caused by severe whipworm infestation include diarrhea, blood loss and weight loss. Whipworms rarely infect humans.

Tapeworms: Named for their resemblance to tape strips, tapeworms live in a dog's small intestine, where they siphon nutrients from his body. Like whipworms, tapeworms rarely infect people.

How to Protect Yourself from Parasite Infestation

Here are some common-sense practices to follow to reduce the chance you'll be exposed to internal parasites from your dog:

  • Treat your pet promptly for any external or internal parasites he may have
  • Wash your hands well after petting any animal or gardening
  • Wear shoes when outside
  • Prevent infants and children from putting dirt in their mouths
  • Remove dog waste from your yard daily, especially in areas where both children and animals play
  • Test your pet annually (or more often, if your veterinarian recommends it) for parasites and give medications to control zoonotic parasites throughout the year