Heartworm

Heartworm

Heartworm disease is a serious and potentially fatal disease seen in all mainland states of Australia. Dogs are more susceptible to heartworm infestation than cats, and heartworm disease also tends to be more severe in dogs. Adult worms live within the heart and large blood vessels where they can grow to more than 30 cm in length. Heartworm larvae, more commonly called microfilariae, can also be found circulating in an infected dog’s blood.

How is heartworm in dogs spread?

Heartworms are transmitted from one dog to another by mosquitoes, which pick up the tiny microfilariae when they bite an infected dog. The microfilariae develop in the mosquito and are transmitted when the infected mosquito bites another dog. The heartworm larvae then migrate through the dog’s tissues and circulatory system, eventually reaching the heart and lungs where they grow into adult heartworms.

Why is heartworm disease dangerous?

Heartworm may cause no clinical signs in the early stages of infestation, but as the worms grow and mature, they can interfere with the normal circulation of blood. This can result in signs of heart failure, and in some cases may lead to sudden death.

Heartworm has a complicated life cycle.

Infected dogs have microfilaria—an immature form of heartworm—circulating in their bloodstream.  Microfilariae are sucked up by mosquitoes 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 in the heart they can cause a physical blockage as well as thickening of the heart and associated blood vessels.  In the earlystages 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 health care routine.

If your pet has not been on heartworm prevention we strongly recommend you speak to us about a heartworm test prior to starting a prevention program.

Please call us to discuss the best heartworm prevention program for your pet.