Puppy kisses and kitten cuddles are one of the many joys of pet ownership, but getting up close and personal can impart more than fur and slobber. Puppies and kittens often carry intestinal parasites, either transmitted by their mothers, or picked up in the environment. Older pets are also susceptible to these nasty worms, especially if they’re stressed or have a compromised immune system.

Intestinal parasites are a danger to people, as well. Many parasite species can be passed from pet to person, or pet owners can become infected when they contact something that’s been contaminated in the environment. Keep your family members, both two- and four-legged, safe from illness caused by these common intestinal parasites:

  • Roundworms — The most common intestinal parasite identified in cats and dogs, roundworms have a spaghetti-like appearance and a round body structure, are several inches long, and are white to light brown in color. Similar to the after-effects of a heavy pasta dish, a large load of roundworms can make pets look potbellied, as well. Puppies and kittens routinely have this bulging appearance, as they are often born with roundworms passed through the uterus. Roundworms can also be transmitted through a mother’s milk, by ingesting infected animals, or from contact with infected feces. Ingested roundworm larvae make their way to the liver, where they mature into adults. The adult worms then migrate to the lungs, where they are coughed up and swallowed, finally taking up residence in the intestinal tract. Roundworm eggs are passed in the stool, developing into larvae before ingestion by another host. People can become infected with roundworms while cleaning up after their pets, and may suffer from liver, eye, or central nervous system damage caused by migrating roundworms.

  • Tapeworms — These worms are commonly associated with flea infestations. Pets ingest infected fleas when they groom themselves, allowing a tapeworm infection to develop. Pet owners often notice their pet’s tapeworms in the form of worm segments that look like grains of rice in the stool or underneath the tail. Tapeworms are difficult to detect from a fecal exam, so diagnosis is usually dependent on visual evidence on the pet. Another less common species of tapeworm—the Taenia species—is transmitted through ingestion of an intermediate host, such as a rabbit or mouse. Regardless of species, tapeworm treatment is the same. Tapeworm infection in humans is not common, as tapeworm eggs must be swallowed to be passed to another host, and that occurs only through accidental ingestion of an infected flea.

  • Hookworms — These nasty intestinal parasites affect dogs more often than cats. They are transmitted in a variety of methods: fecal-oral route, in utero, during nursing, larval penetration of skin, ingesting a small animal infected with hookworm larvae, or eating a cockroach containing the larvae. People are often infected by contaminated soil or feces, but their hookworm infection rarely develops deeper than the skin. Hookworms attach to the intestinal tract and feed on their host’s blood, causing anemia, diarrhea, weight loss, weakness, and blood in the feces. A hookworm infection is particularly dangerous in small puppies and kittens, who can quickly lose a fatal amount of blood. Hookworms are significantly smaller than roundworms and may not be seen in your pet’s stool.

  • Whipworms — An especially hardy species, whipworms, as eggs, can lie dormant in the soil for years. Whipworms are also difficult to detect, because they pass fewer eggs than other intestinal parasites. Pets infected with whipworms often show no signs until the parasite load is heavy, when they will display weight loss, diarrhea, and mucus-coated stool. Fortunately, whipworm infection in people is rare.

  • Giardia and coccidia differ from other intestinal parasites—they’re protozoans, not worms, and tend to be species-specific, which means human transmission is rare. Protozoal infections are most commonly seen in young animals, stressed pets, or animals with compromised immune systems. A surge of protozoal infections is often seen in animals in crowded shelters.

Protect your pet from intestinal parasites

Prevention is key to avoiding intestinal parasite overload. Many heartworm preventives also offer intestinal parasite deworming, so set a reminder for your pet’s monthly preventive. As well as monthly deworming with a heartworm preventive, an infected pet requires a parasite-specific dewormer. Fecal exams are necessary to determine which parasite is setting up shop inside your pet, but a negative fecal exam doesn’t mean she is parasite-free, because parasites shed eggs intermittently, and detection can be difficult. If your pet is suffering from diarrhea, blood in her stool, or chronic weight loss, she may have fallen victim to a hidden parasite infection.

Prevent infection in other pets and yourself by taking proper precautions when scooping the litter box or cleaning up the backyard. Always scoop quickly and daily to limit contamination, and be sure to wash your hands afterward.

Has your pet left more than a regular deposit? Bring it by—we’d love to take a closer look, check for worms, and set her up with the appropriate preventives.