Heartworm disease is a serious and potentially fatal condition that affects dogs across the United States. In this educational webinar, Dr. Marty Greer, Director of Veterinary Services at Revival Animal Health, explains how heartworm is transmitted, the early signs and symptoms to watch for, and the most effective prevention methods. Understanding how to protect dogs from heartworm is essential. Learn how to recognize heartworm symptoms, why annual testing matters, and how to use dual defense strategies, including heartworm preventives and flea and tick protection, to keep your dog healthy year-round.

*This is just a brief overview—watch the full webinar for all the in-depth details of canine heartworm!

Why Dual Defense Matters for Heartworm Prevention

Heartworm disease is a serious threat to dogs, and effective prevention requires more than just a heartworm preventive alone. That’s where dual defense comes in a combination approach using both a heartworm preventive and a flea and tick control product. By combining these tools, pet owners can reduce the number of mosquito bites dogs receive, lowering the chances of heartworm transmission. This strategy is known as “double defense” and is one of the most effective ways to protect your dog.

Revival’s Flea and Tick Finder makes it easy to compare top parasite preventatives and choose the right one for your pet’s needs. While many products offer protection against fleas and ticks, not all of them prevent heartworm disease. That’s why it’s important to check your product carefully as some only guard against external parasites and don’t include heartworm protection. Use the Flea and Tick Finder to explore trusted brands and find options that offer dual defense, helping keep your dog safe from both biting pests and the life-threatening risks of heartworm.

Understanding Parasites and Heartworm Disease

Parasites are organisms that live in or on a host, benefiting at the host’s expense; think fleas, ticks, roundworms, and yes, heartworms. A truly effective parasite doesn’t kill its host because it needs it to survive. Heartworms, however, can cause significant harm to dogs by living in their lungs and heart. Despite the name, heartworm disease affects the lungs just as much as the heart. Dogs are the primary host, but the disease can also affect cats, ferrets, coyotes, and other animals. In rare cases, even humans with compromised immune systems have been affected. Heartworms are transmitted when a mosquito bites an infected dog and later bites another, completing a complex life cycle that requires the mosquito to serve as an intermediary host.

How Heartworms Are Transmitted and Why Year-Round Prevention Matters

Heartworm larvae, known as microfilariae, live in the blood of infected dogs and are picked up by mosquitoes when they bite. These larvae mature within the mosquito and are later transmitted to a new host during another bite. A common misconception is that dogs who spend most of their time indoors are safe from heartworm, but that’s simply not true. Mosquitoes can bite during even brief outdoor potty breaks, and exposure can happen any time of day, not just at dawn or dusk. Once infected, a single dog can lead to a 70% transmission risk to others in the same household or kennel through local mosquito populations. That’s why consistent, year-round heartworm prevention is crucial—indoors or out, summer, spring, fall or winter, every dog is at risk without it.

Early Signs of Heart worm Disease in Dogs Are Often Missed

Heartworm disease in dogs is especially dangerous because symptoms can be subtle or completely absent in the early stages. Many infected dogs appear healthy during their first veterinary visit, only to later show signs like a mild cough or heart murmur. Common heartworm symptoms in dogs include reduced energy, fatigue after exercise, coughing, and in advanced stages, heart failure, liver damage, or kidney failure. Because heartworms take about six months to mature after a mosquito bite, dogs can test negative while still carrying larvae. This long incubation period makes annual heartworm testing and year-round prevention essential. Catching the infection early improves the chances of successful treatment and recovery.

Why Annual Heartworm Testing and Year-Round Prevention Matter

Even if your dog is on monthly heartworm preventives, annual testing is still necessary. Heartworm preventives may fail due to incorrect dosing, skipped treatments, or product resistance, especially in high-risk areas like the Southeastern United States. Misunderstandings, such as confusing flea and tick medication with heartworm prevention, are also common. Yearly heartworm blood tests can detect infections before symptoms begin, which is crucial for successful treatment. At Revival Animal Health, we offer trusted veterinary heartworm test kits like the Abaxis Heartworm Test, which can be used at home by trained pet owners. However, all positive tests should be confirmed by a veterinarian with additional diagnostics. Heartworm disease is serious but preventable—keep your dog protected with consistent monthly prevention and annual testing.

Make Heartworm Prevention Easy with Revival’s AutoShip Program

Staying consistent with your dog’s heartworm prevention is critical and Revival Animal Health’s AutoShip program makes it effortless. By enrolling in AutoShip, you’ll never miss a dose of your dog’s heartworm preventive medication. Choose from trusted brands like Iverhart Plus, Heartgard Plus, and Sentinel, and have them automatically delivered to your door on a schedule that fits your dog’s needs. AutoShip ensures year-round protection against heartworm disease, while also saving you time and money with exclusive discounts. It’s the simplest way to stay on track with monthly heartworm prevention and protect your dog from the serious health risks caused by mosquitoes and parasites. Sign up today to keep your dog safe every month, without the worry. If you have additional canine heartworm questions or need help transferring your dog’s heartworm prescription to the Revival Animal Health Pharmacy for easy home delivery, call us at 800.786.4751.