Most dog owners think of fleas and ticks as a summer problem. Once the weather cools, the collars come off and the preventives go back in the cupboard. But parasites don’t actually follow the calendar. In reality, they’re evolving to survive longer, spread faster, and remain active in conditions that used to be considered “safe.”
At Renfrew Animal Hospital, we see more year-round parasite cases now than ever before. Understanding how these pests behave—and how prevention works—can keep your dog comfortable, healthy, and parasite-free in every season.
Why Parasites Are No Longer Seasonal
It’s easy to assume that fleas, ticks, and mosquitoes die off in the winter. But thanks to milder winters, indoor heating, and urban wildlife, they’re finding ways to thrive all year.
- Fleas can live indoors and in garages, feeding and reproducing even when it’s freezing outside.
- Ticks stay active in temperatures above 4°C and can attach to your dog on a mild winter walk.
- Mosquitoes, which spread heartworm, can survive in basements and greenhouses or hatch early in spring.
The takeaway: skipping prevention for a few months can undo all your efforts from the rest of the year.
The Hidden Risks of Fleas, Ticks, and Heartworms
Beyond the itching and scratching, parasites can carry serious diseases. Fleas transmit tapeworms and Bartonella (cat scratch fever). Ticks spread Lyme disease and anaplasmosis. Mosquitoes can pass on heartworm, a potentially fatal condition where worms grow in your dog’s heart and lungs.
These aren’t rare cases—they’re growing in frequency across Canada, especially in areas where wildlife like deer, raccoons, and foxes are common. Even indoor dogs are at risk if other pets or visitors bring parasites into your home.
Prevention That Works Year-Round
The best parasite control plan is proactive, not reactive. Your vet will tailor it to your dog’s age, size, lifestyle, and regional risks, but here are key strategies that make a real difference:
1. Keep your dog on a preventive all year.
Modern flea, tick, and heartworm preventives are safe and effective when used continuously. Stopping them seasonally gives parasites a chance to rebound. Vets can recommend an all-in-one chewable or topical product that covers multiple parasites at once.
2. Combine medication with environmental control.
Vacuum frequently, wash your dog’s bedding in hot water, and treat yards or pet areas if needed. Fleas and ticks often reappear from eggs or larvae hiding in cracks, rugs, or soil.
3. Schedule regular screenings.
Even when on prevention, annual parasite testing is important. Heartworm and tick-borne diseases can sometimes slip through if a dose was missed or vomited up. Early detection ensures quick treatment and less long-term damage.
4. Adjust prevention with lifestyle changes.
If your dog starts hiking, swimming, or visiting dog parks more often, let your vet know. Exposure levels can change seasonally, and preventive doses or products may need to be updated.
5. Watch for subtle signs.
Persistent scratching, scooting, coughing, or sudden tiredness may all be parasite-related. Because some symptoms mimic allergies or infections, it’s worth asking your vet to rule out parasites before trying new treatments.
The Role Of Your Vet In Preventive Care
Every dog’s environment and immune response are different, so there’s no universal parasite plan. At Renfrew Animal Hospital, we take a personalized approach. We assess where your dog spends time, the local climate, and any pre-existing health concerns to build a prevention routine that actually fits your life.
We also focus on education—helping pet parents recognize early warning signs and understand how products work, rather than just prescribing medication. Because prevention isn’t about one pill; it’s about staying a step ahead.
The Bottom Line
Parasite protection shouldn’t be a seasonal chore. It’s part of year-round wellness care. A few months of missed prevention can undo a year of effort and expose your dog to unnecessary risk.
By keeping up with continuous protection, regular screenings, and open communication with your vet, you can give your dog the comfort and safety they deserve—every month of the year.
At Renfrew Animal Hospital, we’re here to help you build a parasite prevention plan that’s simple, safe, and effective all year round.
