• Bakers Hill Veterinary Hospital
  • (08) 9574 1061
  • 4609 Great Eastern Highway, Bakers Hill

There are two broad categories of worms that may affect our pet dogs and cats, heartworm and intestinal worms.  Please see our intestinal worm page for more information.


Heartworm, or Dirofilaria immitis, is a parasite that is spread by mosquitoes, so you pet does not even need to be in contact with other pets to become infected!

Heartworm has a complicated life cycle.  Infected dogs have an inmature form of heartworm larvae, known as microfilaria, circulating in their bloodstream.  Microfilariae are sucked up by mosquitoes when feeding on the blood of infected dogs. The immature parasite develops into a heartworm larva inside the mosquito, then a single bite from a carrier mosquito can infect your pet (dog or cat). As the worms mature they make their way to the chambers and large vessels of the heart where they can cause a physical blockage as well as thickening of the heart and associated blood vessels.  In the early stages of infection there may be no visible signs, however, infection may eventually lead to signs of heart failure (reluctance to exercise, lethargy, coughing) and even death. Heartworm is present throughout most of Australia (except Tasmania and arid areas).

Thankfully, heartworm is very easy to prevent and should form part of your pet's health care routine. We have very effective preventative treatment options available including tablets, chews, spot-on's and even an injection for dogs administered by one of our vets. The injection gives your pet a year of protection and is often administered at the time of the annual health check and vaccination. If your pet has not been on heartworm prevention we may recommend a heartworm test prior to starting a prevention program, sometimes followed by a repeat test 6 months after commencing heartworm prevention.

Many of our clients are providing their pets with easy, reliable heartworm prevention by using the annual injection, but please call us to discuss the heartworm prevention most suited to you and your pet.