When someone (dog daycare, vet, training facility, etc.) asks you about flea control, they almost always follow up with “What about heartworm prevention?” But, if you are like me, no one has ever really explained what exactly this heartworm is, what to watch for, and what the dangers are. So, Dr. Jules Benson, VP of Veterinary Services at Petplan Pet Insurance answered a few of the most important questions about this Deadly parasite.
What exactly is a heartworm and why is it so dangerous?
Dr. Benson: A heartworm is a parasitic worm that takes up residence in the heart and surrounding arteries. Adult heartworms can reach lengths of up to 14 inches, and dogs with severe cases can be living with more than 100 worms! A heartworm infection can be life threatening – if the worm burden climbs high enough, the worms in the heart cause a decrease in the functional capacity of the heart chambers, leading to heart failure.
Does a dog show any symptoms when they have one?
Dr. Benson: Dogs don’t initially show symptoms, but as the disease progresses you may notice:
- A new-found intolerance of exercise
- A mild but persistent cough
In more severe cases, you may notice:
- Persistent coughing
- Trouble breathing
Your veterinarian can check for heartworms with a simple blood test – and many dogs have this done at the annual wellness visit.
I have heard your dog needs to be tested before being put on medication, because if it has a heartworm already, it will kill the dog – is that true and if so why?
Dr. Benson: If your dog has been off heartworm medicine it is important to schedule a blood test to confirm that he’s not infected before beginning monthly doses of heartworm preventatives.
If your pup is heartworm positive, the preventative medicine may not be safe or effective in treating the existing worms – but take heart; that treatment is available. Your veterinarian can administer a series of injections over the course of a month that will slowly kill the adult worms. At the same time, the dog will also be given medicine to kill the microfilaria (baby worms).