Heartworm is easy to prevent, but difficult & expensive to cure!

What is heartworm?

  • A parasitic roundworm that is spread through the bite of an infected mosquito.
  • It lives in your dog’s heart, lungs, liver and kidneys. If left untreated, your pet will die.
  • A dog is usually infected with about 15 heartworms, but could have as many as 250.
  • Heartworm is not contagious. The only way your pet can get heartworms is from mosquitos.
  • People don’t need to worry about getting heartworm.
  • If you own cats or ferrets, ask your vet about their needs, too.


After a dog is bitten by an infected mosquito, heartworm larvae mature into adult heartworms under the dog’s skin. They burrow into its heart and lungs, and can live up to 7 years. They release their larvae into the dog’s blood, which can be picked up by a mosquito, and the cycle continues.


Dogs should always be on heartworm medication. It’s difficult to diagnose and treat, but simple to prevent. Make sure you give your dog the heartworm medication (usually pills) prescribed by your vet. When taken regularly, these drugs protect more than 99% of dogs from heartworm. It’s safe and easy!


How badly your pet is affected by heartworm depends on how long they’ve had the disease, how many worms are in their body, and your dog’s activity level. Some dogs don’t show symptoms at all. Others may show typical signs, such as:

  • cough
  • troubled breathing
  • tired after exercise
  • coughing up blood
  • weight loss
  • heart failure


There are drug treatments available for dogs with heartworm, but it can cause serious complications for the dog’s health and is very expensive for owners (X-rays, blood tests, hospitalization, injection costs). After a discussion with a vet, many dog owners decide to have their pet put down instead of heartworm treatment.

For more information

Kenora Veterinary Clinic 1-807-468-7441