Dog Heartworm - Detecting And Preventing Dog Heartworm Disease

What is heartworm disease and how can it affect my dog?

Heartworm disease is a condition in which foot-long spaghetti-like worms accumulate inside the hearts of dogs. This condition then results in the heart no longer being able to effectively pump blood throughout the body. Heartworm disease is ultimately fatal if left untreated.

Dr. Sylvalyn Hammond
Clements Ferry Veterinary

How would my dog catch heartworm?

Heartworm is spread through mosquito bites, similar to malaria disease in humans. It takes a single mosquito bite for a microscopic baby worm to swim out of the mosquito and into the body of the dog. The baby worm usually swims around for about three months before making its way to the heart, where it grows over the next three months into an adult heartworm. The adult heartworms then give birth to live microscopic baby heartworms that start circulating in the dog's bloodstream. Some of these heartworm babies will be spread to other dogs through mosquito bites, while others will make their way back to the dog's heart, leading to a worsening infection of heartworm disease.

Can dog heartworm be prevented?

Luckily, with modern science and medicine, heartworm is very easily prevented these days. You can give your dog a once-monthly oral tablet such as Heartguard, Interceptor, or Simperica Trio, which protect against heartworm by killing any baby heartworms that have found their way inside your dog. Other options include topical treatments like Revolution, which is applied to the back of the dog's neck and absorbed, and the ProHeart injection, which is a slow-release fluid deposited under the dog's skin and provides protection for either six months or a year.

What are the signs in my dog that would indicate they may have heartworm?

One of the first signs you'll notice in a dog is coughing, which occurs because the long spaghetti-like worms start poking out of the ends of the heart and into the lung fields. Other early signs include lethargy, decreased playfulness or activity, and exercise intolerance, meaning that the dog gets worn out more easily than before.

What are some middle to late stage symptoms of heartworm?

Late-stage symptoms of heartworm disease are very similar to heart failure symptoms. The dog's cough may sound wetter, and fluid can accumulate in the lungs. There may also be an increase in fluid in the dog's abdomen, causing a potbellied appearance, and their liver might be enlarged. Dogs with late-stage heartworm disease may also experience weight loss due to a lack of appetite.

If my dog has heartworm, what can be done to stabilize my dog's heartworm disease?

The earlier heartworm is detected, the better, as early-stage heartworm is less severe and easier to treat. If your dog tests positive for heartworm disease, treatment will be based on the stage of the disease. This may include stabilizing heart failure, but if caught early enough, adult heartworms can be treated and killed with a series of three injections. However, the treatment process can be long, painful, and uncomfortable for dogs, so prevention is always preferable.

How soon should I bring in my dog to see a veterinarian for heartworm prevention?

The sooner, the better. Veterinarians can safely begin heartworm prevention in puppies as early as eight weeks old. However, it's never too late to start your dog on heartworm prevention, no matter how old they are.

How will a veterinarian diagnose if my dog has heartworm?

Heartworm is easily diagnosed with a simple blood test, which checks for the presence of heartworm antigen in the dog's bloodstream.

Why is early detection and diagnosis of heartworm so important?

Early diagnosis of heartworm is important because the earlier it is detected, the easier it is to treat. When heartworms stretch out and damage the structures of the heart, that damage is irreversible. Catching heartworm disease before it causes irreparable damage to your dog's heart and lungs is crucial for their long-term health.

If you still have other questions and you'd like to reach out to us, you can call us directly at (843) 471-1711, or you can email us at [email protected]. But please do reach out, and we'll get back to you as fast as we can. Don't forget to follow us on social media,