Heartworm Prevention for Pets | Greenway Animal Hospital

Heartworm disease is one of the most dangerous yet preventable conditions that can affect dogs and cats. Transmitted by mosquitoes, heartworms are parasitic worms that live in the heart, lungs, and associated blood vessels of infected animals, causing severe lung disease, heart failure, and organ damage. At Greenway Animal Hospital, we emphasize the importance of year-round prevention to keep your pet safe and healthy.

In dogs, heartworm disease progresses in stages. Early symptoms may be mild or even unnoticeable—such as a light cough or fatigue—but as the infestation grows, signs like labored breathing, decreased appetite, and weight loss can appear. In advanced cases, heartworm disease can lead to congestive heart failure or sudden death. While cats are less likely to develop full-blown infections, heartworms can still cause significant respiratory and immune system complications.

The good news is that heartworm disease is almost entirely preventable. We recommend monthly preventive medications year-round, even during cooler months when mosquito populations may seem less active. These preventives, available as oral, topical, or injectable options, are highly effective at killing immature larvae before they can develop into adult heartworms. It’s important to administer them consistently, as missing even one dose can leave your pet vulnerable.

Annual testing is also essential. At Greenway Animal Hospital, we perform routine heartworm tests for dogs to ensure their preventive program is working as intended. These tests are simple, fast, and can detect an infection before symptoms become severe. For cats, since there is no approved treatment for adult heartworms, we focus heavily on prevention and may use antibody testing to assess risk.

If your pet does test positive for heartworms, early detection is key. Treatment for dogs involves a series of carefully monitored injections, strict exercise restrictions, and sometimes additional medications to reduce inflammation and manage complications. It’s a complex and expensive process—which is why prevention remains the safest and most cost-effective choice.

We work closely with pet parents to select the right prevention plan based on your pet’s species, lifestyle, and risk level. Our team will also help set up reminders and guidance to ensure you don’t miss a dose. Because heartworm disease doesn’t take a break, neither should prevention.

If your pet isn’t currently on heartworm prevention, or if it’s been more than a year since their last test, now is the perfect time to schedule an appointment at Greenway Animal Hospital at (803)-239-4477 or visit us at 887 Gold Hill Rd Suite D and E, Fort Mill SC 29708. Together, we can ensure your pet is protected—today and all year long.