If you’ve quietly let your dog or cat’s flea, tick and worming routine slide now that the cold has set in, you’re far from alone — and that’s exactly what has vets worried this winter. Fresh research suggests hundreds of thousands of Australian dogs are heading into the coldest months without proper parasite cover, largely because owners assume the risk drops when the weather does. It doesn’t quite work that way here.
The winter myth that’s leaving pets exposed
It feels logical enough: fewer mozzies about, less time at the dog park, more nights curled up on the couch. Surely the parasites have gone quiet too? Recent industry figures point to close to half a million Australian dogs currently going without parasite medication, with many owners citing a colder, quieter winter routine as the reason they’ve eased off.
The trouble is that Australia’s climate rarely delivers a true parasite off-season. Across much of the country — particularly the warmer, more humid northern and coastal regions — fleas, worms and mosquitoes carrying heartworm stay active well beyond summer. Even in cooler southern states, centrally heated homes give fleas a cosy year-round breeding ground in the carpet, bedding and skirting boards.
What’s actually still a threat in an Aussie winter
Winter changes the mix of parasites you’re dealing with, but it rarely removes them. Here’s what commonly keeps ticking over through the cooler months:
- Intestinal worms — roundworm, hookworm, whipworm and tapeworm eggs can survive in soil and yards for months, indifferent to the temperature. Dogs sniffing and licking around parks or the backyard stay exposed all year.
- Fleas — heated homes keep indoor flea life cycles rolling right through winter, which is why many owners see a stubborn infestation that simply won’t clear.
- Heartworm — spread by mosquitoes, which remain active in warmer and northern parts of Australia for much of the year. Missing doses can leave gaps in what is a preventable but serious disease.
- Paralysis and other ticks — while peak tick season eases in the depths of winter along the east coast, milder microclimates and travel can still bring encounters.
The Australian Veterinary Association encourages year-round, veterinarian-guided prevention precisely because risk depends on where you live, your pet’s lifestyle and the season — not a single national calendar.
It’s not only your pet at stake
There’s a human angle here that’s easy to overlook. Several common canine worms are zoonotic, meaning they can pass to people. In a December 2025 survey of just over 1,000 Australian dog owners, around 35% weren’t aware that parasites like hookworm, roundworm and tapeworm can affect human health, and roughly 42% had noticed possible signs of infection in their pet.
Young children are considered particularly vulnerable to worms picked up from contaminated soil or from close contact with an untreated pet. Keeping your dog or cat on a consistent worming schedule is one of the simplest ways to protect the whole household — not just the animal.
A simple winter parasite plan
You don’t need to overhaul everything. A few consistent habits cover most Australian pets:
- Keep up a monthly all-in-one flea, tick and worming product, or the specific combination your vet recommends for your area — don’t skip doses just because it’s cold.
- Worm adult dogs and cats at least every three months, and more often for puppies, kittens and pets in high-risk settings.
- Maintain heartworm prevention year-round if you’re in a mosquito-active region, or ask about the annual heartworm injection for peace of mind.
- Wash pet bedding regularly in hot water and vacuum living areas to disrupt indoor flea cycles.
- Book a mid-year check-up so your vet can adjust the plan to your pet’s age, weight and local risk.
If you’re genuinely unsure what your pet needs, that’s normal — products and risks vary a lot by postcode. Consult a licensed veterinarian for advice tailored to your pet’s health, location and lifestyle.
The bottom line
Winter is a season to adjust your parasite plan, not abandon it. Australia’s warm pockets, humid coasts and toasty living rooms give fleas, worms and heartworm plenty of room to keep going — and a lapse now can be tricky and costly to fix later. A few minutes checking your pet’s next dose is a small effort for a genuinely healthier household.
Frequently asked questions
Do I really need to worm my dog in winter?
Yes. Worm eggs survive in soil and yards regardless of temperature, so most vets recommend worming adult dogs at least every three months, all year round. Winter doesn’t reset the clock.
Can my cat get parasites if it stays indoors?
It can. Fleas thrive in heated homes, and worm eggs can hitch a ride inside on shoes, other pets or prey. Indoor cats generally still need regular flea and worm prevention — ask your vet about the right frequency.
Is heartworm still a risk during the colder months?
In mosquito-active regions of Australia, yes. Missing doses can leave gaps in protection against a preventable but serious disease, so many owners choose year-round prevention or the annual injection.
Are dog and cat worms dangerous to humans?
Some are. Worms such as roundworm, hookworm and tapeworm can be transmitted to people, with young children most at risk. Consistent worming protects your family as well as your pet.
Key takeaways
- Roughly half a million Australian dogs are thought to be going without parasite protection this winter, often due to a false sense of reduced risk.
- Fleas, intestinal worms and heartworm stay active through much of an Australian winter, especially in warm regions and heated homes.
- Around 35% of owners in a 2025 survey didn’t know common worms can affect human health.
- Stick to monthly or vet-recommended parasite products and worm at least every three months, year-round.
- Consult a licensed veterinarian to tailor prevention to your pet’s location, age and lifestyle.
