Heartworm Disease: Protect Your Pet and Slow the Spread

by | Dec 20, 2022 | Lifelearn News

If you are the guardian of a cat or dog, heartworm disease should matter to you.

This life-threatening disease affects pets all over the world and, due to the warming global climate, it’s becoming more prevalent in areas previously considered low risk. Treatment for heartworm disease is costly, complicated, and very hard on a pet’s body. Fortunately, this deadly disease is preventable. In honor of Heartworm Awareness Month, take some time to review how heartworm disease affects animals and the simple measures we can take to protect our pets.

Heartworm disease is spread by hungry mosquitoes when they feed on our pets. The life cycle of heartworm is complicated:

  • It begins when a mosquito bites an infected animal (e.g., dog, cat, fox, coyote) and ingests microfilariae (“baby heartworms”) during its blood meal.
  • The microfilariae develop into larvae inside the mosquito over 10-30 days.
  • The larvae travel to the mosquito’s mouthparts. When the mosquito bites a new animal, the larvae are injected into the animal’s body.
  • Once in the bloodstream, the larvae enter the heart and adjacent blood vessels, mature into adults, mate, and produce microfilariae within six to seven months.

Adult heartworms can grow up to 16 inches (40.6 cm) in length and up to 250 of these worms may reside within an animal’s vital organs. Over time, adult heartworms clog the heart and major blood vessels, reducing blood supply to the body’s organs, and causing them to malfunction. Microfilariae can also block the flow of blood in small blood vessels throughout the body, depriving cells and tissues of nutrients and oxygen. Microfilariae primarily destroy the tissues of the lungs and liver, leading to coughing and cirrhosis (scarring) of the liver. Severely infected dogs may die suddenly during exercise or excitement. In cats, even a small heartworm load can lead to death.

Treatment of heartworm disease is not only expensive and dangerous but there is also no guarantee of success. Treatment for cats is a very difficult process and often comes with a poor prognosis.

Your pet’s best line of defense is annual testing and preventives. Testing for heartworm disease is normally done at this time of year (spring) to check for an infection that may have occurred during the previous warm season. This testing is critical for two reasons: 1) giving heartworm preventive medication to an infected pet can lead to more health complications; 2) if a pet tests positive this year but was negative last year, the infection will be caught early, making its treatment easier and lower risk than in the case of advanced disease.

There are several preventive medication options available through your veterinarian. Depending on where you live, your prescribed preventive may need to be administered only six months of the year or year-round. Oral preventives are flavored, and most pets think of their monthly dose as a special treat! For pets with food allergies or digestive sensitivities, there are topical liquid options. Many heartworm preventives are combined with other ingredients that can protect your pet from intestinal worms, fleas, or ticks. There are so many options and combinations available that it may seem overwhelming when trying to choose the best one for your pet, but this is good – it means there is a solution for just about every pet! Based on risk factors in your geographic area and your pet’s current health status and lifestyle, your veterinarian can recommend the best heartworm and parasite prevention for your pet(s).

According to many experts, the chief hurdle to eliminating heartworm disease is the lack of pet owner compliance with recommended preventive guidelines. When you take simple measures to protect your pet from this heartbreaking disease, you’re also doing your part in reducing the spread to other pets. And that’s a heartwarming (not heartworming) thought!

Note: This article, written by LifeLearn Animal Health (LifeLearn Inc.) is licensed to this practice for the personal use of our clients. Any copying, printing or further distribution is prohibited without the express written permission of Lifelearn. Please note that the news information presented here is NOT a substitute for a proper consultation and/or clinical examination of your pet by a veterinarian.