Parasite Prevention: Myths vs Facts
There's no shortage of information about pet parasites online. Unfortunately, not all of it is accurate. Before you make a decision about the best way to protect your furry friend from parasites, take a look at a few parasite prevention myths and facts.
Myth. Parasite Protection Isn't Necessary for Indoor Pets
Fact. Your pet may never go outdoors, but that doesn't mean parasites won't be a problem. Fleas could enter your home on your clothing or might cling to the fur of outdoor pets. Your pet could also develop intestinal parasites if you or an outdoor pet step on soil contaminated with eggs before entering your home.
Mosquitoes are also a concern, as these insects carry heartworm larvae. The worms grow in your pet's heart, lungs, or blood vessels and can sicken or kill dogs, cats, and ferrets. Heartworm disease has been diagnosed in every state in the U.S., according to the American Heartworm Society. Although your pet may stay inside, a mosquito could fly into your home through a tiny hole in a screen or an open door.
Myth. Parasites Are Always Visible
Fact. You may never see a parasite, but that doesn't they're not causing trouble for your pet. Fleas and ticks can be difficult to spot in your pet's fur. Your pet may have an internal parasite, like roundworms, whipworms or hookworms, even if you never see a single worm.
Myth. Parasites Are a Minor Problem
Fact. Parasites aren't just an annoyance. These pests can make your pet very uncomfortable and cause serious health issues in some cases. Fleas can cause itchy rashes, hair loss, skin infections, allergic reactions, and even anemia. If your pet swallows a flea infected with the tapeworm larvae, tapeworms could make themselves at home in your pet's small intestine. Fleas may also transmit cat scratch disease, feline infectious peritonitis, and bubonic plaque.
Ticks can carry Lyme disease and other serious diseases, like Rocky Mountain Spotted Fever and ehrlichiosis. Worms can interfere with nutrition and cause life-threatening blood loss. Some worms, like roundworms, can be spread to people.
Myth. You Can Use the Same Parasite Prevention Method for All Your Pets
Fact. Using the same medication for all your pets is never a good idea. Parasite prevention medication is specially formulated for specific breeds and types of animals. Dosages may vary depending on the pet's age, size, and health. The American Veterinary Medical Association notes that dog flea products are toxic for cats and can cause death.
Myth. Parasite Prevention Isn't Necessary During the Winter
Fact. Pets need year-round protection from internal and external parasites. Although cold weather may kill fleas outside, fleas inside your warm home can survive and continue to lay eggs. It's impossible to tell when mosquito season will start and end every year. If you guess wrong, your pet may be at risk for heartworm.
Myth. Natural Remedies Offer an Effective Way to Control All Types of Parasites
Fact. You may have read that applying essential oils to your pet's fur is a more natural way to control parasites. Although some essential oils do seem to kill fleas and ticks, the protection can wear off if your pet rolls around in the grass or mud or plays in the rain. Essential oils may be toxic if ingested. If your pet grooms itself or licks an itchy spot, it could swallow the oil and experience nausea, vomiting, diarrhea, trouble breathing, coma, or seizures.
Prescription parasite prevention methods kill adults parasites, eggs, and larvae without harming your pet's health.
Myth. One Dose of a Parasite Medication Is All My Pet Needs
Fact. The first dose of a medication will kill adult parasites, but that only solves part of the problem. As larvae mature, new adults will emerge and continue to cause health issues for your pet. For safety's sake, follow instructions on the package and your veterinarian's recommendations.
Not sure what type of parasite prevention medication your furry friend needs? Contact our office to schedule a visit with the veterinarian.
Sources:
Centers for Disease Control & Prevention: Preventing Fleas, 6/4/2024
https://www.cdc.gov/fleas/prevention/index.html
University of Illinois Urbana-Champaign College of Veterinary Medicine: Prevent the Big Three Pet Parasite, 7/3/2017
https://vetmed.illinois.edu/pet-health-columns/pet-parasites/
American Veterinary Medical Association: External Parasites
https://www.avma.org/resources-tools/pet-owners/petcare/external-parasites
American Veterinary Medical Association: Intestinal Parasites in Cats and Dogs
https://www.avma.org/resources-tools/pet-owners/petcare/intestinal-parasites-cats-and-dogs
American Heartworm Society: Heartworm Basics
https://www.heartwormsociety.org/pet-owner-resources/heartworm-basics
PetMD: Essential Oils for Fleas and Dogs: Is It Safe?, 5/19/2025
https://www.petmd.com/dog/it-safe-use-essential-oils-fleas-and-ticks-dogs
