The adult heartworm, as the name suggests, lives within the chambers of a dog’s heart and in the large blood vessels within the lungs. If there is a sufficiently large worm burden, this can cause heart disease-like symptoms such as coughing, exercise intolerance, and in severe cases can actually lead to congestive heart failure and potentially, death.

Adult worms produce microscopic larvae that circulate within the dog’s blood. Infection occurs when a mosquito bites an infected dog, draws up the larvae during feeding and bites another dog, thereby transferring the larvae across. They then develop into adult worms over the course of six months.

Fortunately, due to our climate and environment within the Melbourne area, mosquito numbers are low and therefore the incidence of heartworm in dogs is also low. Generally the prevalence increases the further north you move.

For dogs that are taken to higher risk areas, prevention is recommended. For dogs over six months of age that have not been on protection against heartworm, a simple blood test is recommended to ensure they are clear of the infection prior to commencing the preventative program.

There is a variety of preventative medications available ranging from liquid applications, to oral tablets and yearly injections. Intestinal-only worming medications will not prevent heartworm infections but there are combination treatments that do prevent both intestinal worms and heartworm infections. Our veterinary team will be able to advise which is the most suitable for your dog.

Heartworm is generally a condition that affects dogs. While cats are also potentially at risk, the larvae do not usually develop fully.

Lort Smith