Busting 5 Myths About Heartworm Disease, Prevention, and Treatment

When it comes to keeping your pets happy and healthy, we believe knowledge is power. Unfortunately, there’s a lot of misinformation out there that isn’t medically sound. Today, we’re addressing some of the common myths and beliefs around heartworm disease, prevention, and treatment. With the right preventative measures, we can protect your pet’s heart health and stop the spread of this deadly disease! 

What Is Heartworm Disease? 

 Heartworm is a serious and potentially fatal disease that affects the lungs, heart, and other organs. It’s caused by a parasitic worm called Dirofilaria immitis. Dogs, cats, and ferrets are all susceptible to heartworm disease. Heartworms also infect wild animals, including wolves, coyotes, foxes, and sea lions. 

How Does Heartworm Disease Spread? 

Heartworm disease spreads through mosquitoes. When a mosquito bites an infected animal, it picks up baby worms called “microfilaria.” These baby worms develop into “infective stage” larvae over a 10-14 day period. Then, when that infected mosquito bites your pet, it deposits those larvae. 

According to the American Heartworm Association, it takes approximately six months for larvae to mature into adult heartworms. Once they’re mature, heartworms can live for 5-7 years in dogs and 2-3 years in cats. Because the worms live so long, each mosquito season can lead to an increased heartworm load in an infected pet. But even one bite from an infected mosquito can be deadly if left untreated.

Getting to the Heart of Heartworm Disease

Even though heartworm disease is preventable, over a million pets in the U.S. have heartworms. According to the American Heartworm Society, heartworm infection has been diagnosed around the globe, including all 50 of the United States. By educating pet owners about the importance of heartworm prevention, we’re hoping to slow the spread! Here are some common and dangerous myths about heartworm disease. 

Myth #1: My pet will show symptoms if they have heartworms

In most cases, there will be few or no symptoms until the disease is severe. That’s because infective stage larvae take up to six months to become mature adult heartworms. Once adult worms begin to reproduce, they start to damage nearby blood vessels and reduce the heart’s pumping ability. 

The longer the infection persists, the more likely it is that your pet will show symptoms. It may be a year or longer before you notice clinical signs of heartworms like lethargy, coughing, or fainting after exercise. In severe cases, pets may develop heart failure and the appearance of a swollen belly due to excess fluid in the abdomen. 

Myth #2: I only need to worry about heartworm prevention during the summer

Anyone who’s ever been to a backyard barbecue knows mosquitoes thrive during the long, warm days of summer. But summer isn’t the only “mosquito season.” While mosquito activity generally begins when temperatures reach 50 degrees Fahrenheit, it’s not unusual for them to stay active into the 40s. 

Plus, hibernating mosquitoes can emerge during unexpected warm spells throughout the fall, winter, and spring. This fact, combined with unpredictable weather patterns, makes it difficult to say exactly when “mosquito season” starts and ends. That’s why we recommend using heartworm preventatives year-round. 

Myth #3: My indoor-only pets don’t need heartworm preventatives

All it takes is an open door or cracked window for mosquitoes to enter your home. And once they’re inside, it only takes one bite from an infected mosquito to transmit this potentially fatal disease. In fact, the American Heartworm Society reports that 25% of cats diagnosed with heartworm disease are indoor-only pets. 

Myth #4: Heartworm disease is rare in Oregon

Unfortunately, heartworm disease is on the rise across the country, including in the Pacific Northwest. According to the American Heartworm Society’s incidence maps, reported positive tests in Oregon increased by 110% between 2012 and 2017. In the first 10 months of 2020, reported cases in Oregon were 33% higher than in all of 2019. 

Experts from the Companion Animal Parasite Council (CAPC) believe a few different things could be contributing to these higher numbers. First, pets who are relocated for adoption after natural disasters often come from areas with higher historical heartworm risks and prevalence. Climate changes could also be a contributing factor, as mosquito populations rise rapidly in warm and wet conditions. Finally, our pets travel with us now more than ever before. Simple summer activities like taking pets camping or hiking in areas with high mosquito counts, such as Southern Oregon, can increase their risk of infection. 

Myth #5: Natural remedies and over-the-counter preventatives work as well as FDA-approved preventatives

Not only is this belief inaccurate, it’s also dangerous! These treatments are not FDA-approved, which means they have not undergone rigorous scientific testing to demonstrate safety and effectiveness for treating heartworms. Worse still, many products marketed as “all natural” contain ingredients that are toxic to pets. For example, one herbal product we researched contains garlic, which can damage a dog’s red blood cells, potentially leading to life-threatening anemia. 

Additionally, trying to treat adult heartworms without veterinary supervision is extremely dangerous for your pet. When adult heartworms die, they begin to decompose. As they break up, they’re carried to the lungs, where they lodge in smaller blood vessels and are eventually reabsorbed by the body. This process can take anywhere from several weeks to months. Most post-treatment complications are caused by these worm fragments, which can block blood flow resulting in severe complications and possibly death.

FDA-approved heartworm preventatives and treatments are the safest way to protect your pets! If you want to use natural repellants, it should be in addition to preventives, not instead of them. 

Heartworm Prevention Is Your Pet’s Best Bet

It’s unfortunately true that heartworm treatments can be costly, dangerous, and painful for our pets. Luckily, heartworm prevention is about as easy as it gets! All it takes is a monthly chewable and annual heartworm testing to protect your pet. And, with our convenient online pharmacy, we’ve made it easier than ever to make sure your pet never misses a dose! Just set up an autoship to have refills delivered right to your doorstep. 

Still have questions about heartworm prevention? Our team has answers! Just schedule an appointment to discuss the best option for your pet, budget, and lifestyle.