Mosquitoes are an annoying part of the Aussie summer – they leave itchy bites and have that irritating whine. It’s well known that in some parts of the world mosquitoes can carry human diseases like malaria. But did you know that mosquitoes can carry something equally deadly to our pets… right here in Australia?

Heartworm is a parasitic worm, but unlike the worms that live in the intestine like tapeworm, it is spread by mosquitoes. When an infected mosquito feeds on your pet’s blood, heartworm larvae enter the bloodstream. Over time, these larvae grow and mature into adult worms that can reach up to 30cm in length – that’s as long as a standard ruler.

Eventually, the heartworms become large enough that they become lodged in the chambers of the heart and here’s where they cause problems – sometimes even fatal heart failure. It’s more common for dogs to contract heartworm disease than cats, but cats can still be at risk and are much more likely to have fatal complications.

Traditionally heartworm is more common in tropical and subtropical regions of Australia but recently the prevalence in southern areas has increased; it’s thought this may be due to an increasing reservoir population of feral foxes and rising temperatures.

Because heartworm disease is reliant on the weather, and the weather has become increasingly harder to predict, so is heartworm disease. Prevention is the most important way to make sure your pets avoid nasty consequences.

It is important to remember that all the products for heartworm are preventatives. This means they need to be given to your pet before they are infected with heartworm. Therefore if you miss a monthly dose and they become infected, the preventative given the following month wont be effective. There are many preventative options to protect your pet from heartworm – most are monthly such as chewable tablets and spot-on drops. There is a yearly injection, which is by far the most convenient because you cannot forget a dose.

Remember that just because it says “allwormer”, the treatment may not cover for heartworm! Always check the packet, or ask your vet if you’re not sure.