Heartworm in Dogs: What U.S. Owners Should Know About Prevention and Testing

Heartworm disease is transmitted by mosquitoes and occurs in dogs throughout the United States. Geographic risk varies, but infected mosquitoes and animal movement make prevention relevant far beyond traditionally warm regions.

How does heartworm spread? Mosquitoes pick up immature heartworms from an infected animal and transmit them when they bite another host. Dogs are highly suitable hosts for heartworms, which can mature and live in the heart and pulmonary blood vessels.

What symptoms can occur? Early infection may cause few obvious signs. As disease progresses, coughing, reduced exercise tolerance, fatigue, weight loss, and breathing problems can develop. Severe disease can lead to heart and lung failure.

Why are prevention and testing both important? The American Heartworm Society recommends year-round prevention and regular testing because missed or delayed prevention can leave gaps. Testing matters because prevention does not eliminate adult infections that are already established.

What if a dog tests positive? Veterinarians typically confirm infection, assess the dog’s overall health and disease severity, and create a staged treatment plan. Activity restriction is an important part of management because vigorous exercise can increase the risk of complications in infected dogs. Treatment can take months and requires close veterinary supervision.

Why not simply wait for symptoms? A dog may have significant heartworm disease before obvious symptoms appear. Prevention is generally safer and far less complicated than treating established adult infection.

Petvimo can help owners track preventive schedules, testing dates, and veterinary follow-up, while the medical plan itself should come from a licensed veterinarian.