Heartworm prevention for Australian pets
Introduction
Heartworm is spread by mosquitoes and can be life-threatening, especially for dogs. Prevention is far easier than treatment. This guide was prepared with input from our lead vet and founder, Dr. Feargus McConnell, BVSc. If you need a one-to-one plan for your household, contact us.
How dogs and cats get heartworm
Mosquitoes pick up microfilariae from infected animals and pass larvae to the next pet they bite. Larvae mature over months into worms that live in the heart and nearby vessels. Year-round prevention stops this cycle.
When to start
Begin as soon as your chosen product’s minimum age and weight allow. Puppies usually start early with monthly dosing. Cats can start monthly prevention once they meet label requirements.
Testing before (or after) gaps
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Dogs: If you are late or lapsed, ask your vet whether a heartworm test is needed before restarting.
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Cats: Routine blood tests are less definitive than in dogs, but your vet may advise testing based on risk and history.
Your simple monthly plan
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Pick a registered product that includes heartworm prevention.
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Dose every month without gaps. Set a repeating phone reminder.
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If you use different products for different parasites, follow the shortest re-dose interval to avoid gaps.
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Before travel to mosquito-heavy areas, check your dosing dates and pack the next dose.
Missed a dose
Give it as soon as you remember and call your vet to ask if testing is needed, especially for dogs.
Safety basics
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Match species, weight band, and minimum age every time.
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Do not stack preventatives unless your vet tells you to.
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Seek vet advice before starting if your pet is pregnant, breeding, or has a health condition.
Products we trust
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Dogs: Simparica Trio Chewable Tablet for Dogs — monthly chew with heartworm prevention, intestinal worms, fleas, and ticks when used as directed.
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Cats: Revolution Plus Spot-On for Cats — monthly spot-on with heartworm prevention plus fleas, ticks and mites.
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Cats: Revolution Topical Solution for Cats — monthly spot-on with heartworm prevention plus fleas and mites.
FAQ
Do I need heartworm prevention year-round?
Yes. Mosquitoes are unpredictable, and prevention only works when you do not miss months.
Can I just use a flea-only product?
Not for heartworm. Make sure the label includes heartworm prevention.
My dog missed a couple of months. What now?
Give a dose today and ask your vet about testing before restarting regular prevention.
A steady monthly routine is the easiest way to keep heartworm off the worry list.
