Your pet depends on you for more than love and treats; they rely on you for protection. One of the most important safeguards you can provide? Year-round heartworm prevention. For National Heartworm Awareness Month at Finn Hill Animal Hospital, we want pet owners to understand how the invisible threat of heartworm disease works and how easy it is to stop with the right care routine.

Heartworm Disease: A Hidden, Serious Threat

Heartworm disease is caused by long worms that look a bit like spaghetti. They live in a pet’s heart, lungs, and surrounding blood vessels. This disease is spread by mosquitoes that carry a heartworm’s offspring called microfilariae. Heartworm in cats and dogs can cause lung damage, heart failure, and organ dysfunction. In cats, even one or two worms can cause sudden death. Because symptoms often don’t appear until the disease is advanced, prevention is the safest and most effective defense.

• Heartworm disease is preventable—but not curable for cats.
• Treatment in dogs is long, expensive, and risky.
• Mosquitoes can bite anytime, anywhere.
• Indoor pets aren’t immune.
• Heartworm prevention is easier and more affordable than treatment

How Prevention and Testing Work to Keep Your Pet Safe

Heartworm preventives don’t stop mosquitoes from biting your pet, but they do kill off the larvae before they become adult worms. Most options are given monthly and come in oral chewables or topical applications. There is also a 6-month or annual heartworm injection available for dogs. These heartworm medications are safe, vet-approved, and offer protection when given on time.

Even if your dog is on heartworm prevention all year, annual heartworm testing is essential.

• Missed or delayed doses can happen.
• Vomiting or spitting out pills may go unnoticed.
• Testing ensures the heartworm medication is working.

A canine heartworm test is quick and requires just a small blood sample. For cats, talk to your veterinarian about heartworm disease testing recommendations.

Frequently Asked Questions About Heartworm

Does my indoor cat really need heartworm prevention?
Yes. Mosquitoes can enter your home through open doors, windows, or screens. Even fully indoor pets are at risk of being bitten, and one bite is all it takes to transmit heartworm. Talk to your veterinarian about heartworm preventatives for your feline during their yearly wellness exam.

Can I skip my pet’s heartworm medication during the winter?
No. Heartworm prevention must be given every month. Skipping doses—even in cold weather—can allow larvae to survive and grow into adult worms.

Is heartworm treatment available for cats that test positive?
Unfortunately, no. There is no approved treatment for adult heartworms in cats. That’s why prevention is especially critical for feline companions.

Start Your Pet’s Heartworm Prevention in Kirkland, WA

Heartworm may be invisible, but prevention doesn’t have to be complicated. With just one monthly dose (or a yearly shot), you can prevent a disease that’s painful, expensive, and often fatal. Trust Finn Hill Animal Hospital to keep your pet covered every month of the year. Protect your pet from heartworm disease today. Book an appointment to schedule a heartworm test or get started on a prevention plan for your pet in Kirkland, Redmond, Bothell, Woodinville, Mill Creek, or a surrounding area.