April brings more daylight, rising temperatures, and people and pets spending more time outdoors. With more time outdoors comes an increased health risk to pets’ health, making it an ideal time to proactively check-in on a pet’s heartworm status and preventatives.
Best Friends Animal Society, a leading national animal welfare organization working to end the killing of cats and dogs in America’s shelters in 2025, encourages pet owners and prospective adopters to educate themselves this Heartworm Awareness Month.
Heartworm is spread through mosquitoes, with many cases occurring near large bodies of water, but it is increasingly becoming present in every state.
“The most common signs of heartworm in dogs are coughing, exercise intolerance, collapsing or fainting episodes, decreased appetite, and weight loss,” said Dr. Erin Katribe, Director, National Veterinary Programs, Best Friends Animal Society. “Infection is less common in cats, but the disease can present as an asthma-like cough.”
Dr. Katribe offered the following five facts to help educate pet owners on heartworm disease prevention:
- Keep dogs and cats on a chosen preventative year-round, regardless of location, because heartworm disease is becoming more rampant across the country.
- Even if a dog tests negative without being on preventatives, they could still test positive in six months as it takes that long to develop and be visible on standard screenings.
- If a dog does test positive for heartworm, it’s important to understand that the majority of dogs go through treatment without any complications. The treatments used today are much safer than those used in previous generations, so heartworm should no longer carry a stigma.
- Many shelters that are struggling with overcrowding across the south are the same shelters with a high prevalence of heartworm disease. Sadly, heartworm positive dogs are the first to be killed when capacity becomes an issue, so they’re an at-risk population in shelters. The great news is that heartworm isn’t directly transferable to other pets in the household, so there is no reason not to foster or adopt a heartworm positive dog.
- Cats can get heartworms, too, and there is currently no treatment. Cats should be on preventatives, especially in endemic areas.
“If you have the ability to help a heartworm-positive pet by adopting or fostering, please bring one home when you can,” Katribe said. “The process of treating heartworm is not as difficult as it used to be and you’ll be helping a pet that really needs you.”
For additional information on heartworm disease or opening your home to pet in need, visit bestfriends.org.
