Heartworm Is Preventable, but Study Finds Common Myths Leave Pets Unprotected
Heartworm is a dangerous and potentially fatal parasite that poses a risk to dogs and cats during all four seasons, yet 51 percent of pet parents skip year-round prevention, a recent survey found.
Despite the growing prevalence of heartworm disease in the U.S., nearly 40 percent of dog and cat owners surveyed said they don’t believe their pet is at risk of getting heartworms. Further, nearly 30 percent indicated that their pet is not on heartworm prevention at all.
A dog or cat can get heartworms through the bite of an infected mosquito. The survey found that 21 percent of pet owners don’t believe the mosquitoes in their state carry the parasite, even though heartworm disease has been diagnosed in all 50 states.
Why Are Heartworm Cases on the Rise?
Heartworm rates continue to trend upward in “hotspots” and locations where cases were once rare, the American Heartworm Society’s 2022 Heartworm Incidence Map shows. Multiple factors may play a role in the increase in heartworm prevalence in certain parts of the country, including:
- Poor compliance with heartworm prevention
- A greater influx of heartworm-positive pets from out of state
- Higher heartworm testing rates
“The gap in prevention measures surely plays a role, but that’s not all there is to the rise in heartworm infestation,” says Dr. Rhiannon Koehler, a veterinarian in Overland Park, Kansas. “Climate change is causing the ranges and active seasons of mosquitoes that carry heartworms to expand, making heartworm infestation an increasingly widespread issue.”
States with the highest increases in heartworm diagnosis over the past five years include Delaware, Montana, Nevada, Idaho and Utah, Banfield data shows. Meanwhile, Connecticut had the largest decrease in the rate of pets diagnosed with heartworms, down 46 percent.
Why Is Year-Round Heartworm Prevention So Important?
It is important to protect pets from heartworm year-round, not just during warmer months. “The ranges and active seasons of mosquitoes that carry heartworms are expanding,” Dr. Koehler explains.
However, 41 percent of surveyed pet owners believe heartworm is only a risk during certain parts of the year. In addition, 18 percent said they only use a preventative during spring and summer months.
Heartworm prevention is safer and more affordable than treatment, Dr. Koehler stresses. “Treatment for heartworms in dogs involves a series of injections of an arsenic-based medication to kill the heartworms and can cost over $1,000,” she says. That can be hard on a dog and a huge strain on a pet parent’s pocketbook.
Although dogs are the preferred host for heartworms, cats can get heartworms, too. The report noted a 47 percent increase in heartworm cases in cats over the past five years. Unfortunately, there is currently no safe and approved treatment for cats with adult heartworms. “We have to wait for cats to either clear the heartworms on their own or succumb to the heartworms,” Dr. Koehler says. “For cats, even a small number of heartworms can be life-threatening.”
The good news is that heartworm is easily preventable in both dogs and cats. “Your veterinarian can work with you to find a safe preventative for your pet,” Dr. Koehler says. “You have options!”
