The Importance of Year-Round Flea, Tick & Heartworm Preventatives

As the weather cools, many pet parents assume they can pause their pet’s flea, tick, and heartworm prevention. However, cold weather doesn’t eliminate these parasites.

Even though freezing outdoor temperatures may reduce the number of pests, flea eggs and immature stages are much more resilient than most people realize. They can withstand cooler conditions and continue developing inside warm homes or sheltered areas.

Tick activity typically decreases when temperatures fall below about 40°F, but ticks have evolved clever survival methods. Many species enter a dormant state during cold periods, hiding in leaf litter, under snow, or beneath soil and brush. Once conditions warm slightly, they quickly become active again—sometimes even on mild winter days.

Heartworm disease is spread by mosquitoes, whose populations may decline in cooler months. However, some mosquito species can overwinter in protected environments such as basements, garages, and other sheltered urban areas. These survivors can still transmit heartworm larvae to dogs and cats, which is why consistent prevention remains essential.

Why Year-Round Protection Matters

• Unpredictable weather patterns: Warmer winters and unseasonably mild days allow parasites to stay active longer each year.
• Indoor infestations: Fleas and mosquitoes can thrive inside heated homes, where temperatures stay comfortable year-round.
• Heartworm incubation: Preventatives kill immature larvae from earlier mosquito bites. Skipping doses allows infections to develop unnoticed.

Keep Your Pet Protected Every Month

Veterinary experts recommend year-round use of parasite preventatives for all pets, regardless of climate. Consistent, monthly protection is the best strategy to prevent costly infestations, discomfort, and serious illnesses.

Even as temperatures cool, maintaining your pet’s flea, tick, and heartworm prevention schedule ensures their safety and well-being—no matter the season.

Talk to Your Veterinarian about Protecting Your Pet

Your veterinary team can help you choose the right year-round prevention plan for your pet’s lifestyle and health needs.