Does My Dog Really Need Heartworm Protection?

By: DogTrekker Staff

By Rhonda Stallings, DVM, Arroyo Veterinary Hospital, Sonoma, CA

Kid hugging his dog at the vet

By Rhonda Stallings, DVM, Arroyo Veterinary Hospital, Sonoma, CA
Heartworm disease now exists throughout the United States though some areas pose more risk than others. In California, there are so many microclimates that we just cannot say any one area is safer than another. And, since we travel with our dogs, even just from a park to the beach, our pets are exposed to mosquitoes that carry this dreaded parasite. DogTrekkers may travel to a county where heartworms are more common and not even realize it. More…


Heartworm disease is also spreading to new regions of the country each year. Stray and neglected dogs, and certain wildlife such as coyotes, wolves, and foxes can be carriers of heartworms. Mosquitoes blown great distances by the wind, and the relocation of infected pets to previously uninfected areas, all contribute to the spread of heartworm disease. This happened following Hurricane Katrina when 250,000 pets, many of them infected with heartworms, were adopted and shipped throughout the country.

The safest thing to do, and the best insurance against infection, is to administer a year-round heartworm preventive as directed by your veterinarian. If you do this as scheduled, the chance of your pet developing an infection is extremely low. If you do not have your dog on heartworm prevention you are taking a risk with her health and may also unknowingly be spreading heartworm wherever you go, by having a heartworm-positive dog infect mosquitos that aren’t carrying the disease.

Why test your dog for heartworms annually, even if it’s on year-round preventive medication? While heartworm preventives are nearly perfect, mistakes happen. People miss doses, or fail to give it on the same day ­each and every month. Pets vomit frequently, and at times “lose” their dose of prevention. Sometimes they spit it out without you noticing. Because of this, all pets should be tested for heartworms every 12 months, usually during the annual preventive exam. If this serious disease is present, it can be treated as soon as possible.

For more information about heartworm, visit The American Heartworm Society.