It’s easy to be cavalier about parasites in dogs and cats. Many can’t be seen, while others (fleas, we’re looking at you) are often thought of as an annoyance rather than a “real” health problem. But pet parasites are truly dangerous—here are five of the worst.
1. Heartworms
Heartworms have been diagnosed throughout the United States, but are especially problematic in the southern tier of the country, from Texas through the Carolinas. Mosquitoes pick up heartworm larvae from an infected dog and transmit them to other animals via their bites. Without expensive treatment, heartworm in dogs is often fatal. Thankfully, heartworm prevention is cheap, safe, and very effective, particularly when used all year round.
Cats are not immune to heartworms. In comparison to heartworm in dogs, the feline form of the disease is seen less frequently. However, treatment is even more difficult, which makes giving heartworm prevention to cats very important.
2. Ticks
In and of themselves, ticks are not all that dangerous, but tick bites are responsible for transmitting many serious diseases. For example, Lyme disease and anaplasmosis are common in the Northeast and upper Midwest, while ehrlichiosis is diagnosed throughout the U.S. Depending where you live, you might also have to worry about babesiosis, Rocky Mountain spotted fever and tick paralysis.
The best way to protect against diseases transmitted through tick bites is to use an effective tick preventative. Also, check pets for ticks after they’ve spent time outside and quickly remove any that you find.
3. Fleas
Fleas don’t just make pets itchy; they can also spread diseases like typhus, plague and bartonellosis to pets and to people. Dogs and cats (and less commonly, people) can also get certain types of tapeworms after they ingest a flea carrying immature forms of the parasite. As if all that weren’t bad enough, fleas eat your pet’s blood, and large numbers can lead to anemia. Be sure to guard against infestations with an appropriate flea preventive.
4. Toxoplasmosis
Cats play a pivotal role in the lifecycle of the microscopic, single-celled parasite Toxoplasma gondii. Infected cats shed oocysts (tiny parasite eggs) in their feces, which contaminate the environment, transmitting the microorganism to other animals and sometimes people.
Most healthy adults do not become sick after exposure to Toxoplasma. However, the very young or individuals with compromised immune systems can develop potentially life-threatening problems associated with the infection. Most importantly, miscarriages and birth defects are possible if a pregnant woman is infected with Toxoplasma for the first time during her pregnancy.
To prevent toxoplasmosis, keep your cats indoors, do not to feed raw foods and dispose of cat feces every day—before oocysts can mature to the point where they are infectious.
5. Intestinal Worms
Roundworms and hookworms are commonly diagnosed intestinal worms in dogs and cats. They are especially dangerous for young animals, which is why veterinarians routinely recommend deworming puppies and kittens several times throughout their first year of life. Roundworm and hookworm larvae can also infect people.
Of course, this is not a complete list of potentially dangerous parasites in dogs and cats. Talk to your local veterinarian about which pet parasites are common where you live and the best ways to prevent them.