While thankfully rarer in Canada than the warmer climates to our South, we do still see several heartworm cases a year in our area. When mosquitoes bite, they can transmit heartworm infection between animals. Heartworm can severely and sometimes fatally damage the heart, lungs, and blood vessels. Some pets may not show any signs of infection; in those that do, symptoms can vary widely.

In dogs, signs of heartworm disease can range from coughing, fatigue, and weight loss to difficulty breathing and a swollen abdomen (caused by fluid accumulation from heart failure). Canine heartworm infection can also lead to a life-threatening complication called “caval syndrome” (a form of liver failure); without prompt surgical intervention, this condition usually causes death.

Although often thought to not be susceptible to heartworm infection, cats can indeed be affected. Cats can suffer from a syndrome referred to as heartworm-associated respiratory disease (HARD); the symptoms can be subtle and may mimic those of asthma or allergic bronchitis. Signs of respiratory distress, such as rapid or difficult breathing, wheezing, and panting, are common. Heartworm infection is more difficult to diagnose in cats than it is in dogs.

Treatment for heartworm infection is far more expensive than prevention, and unfortunately has significant possible side effects. There is currently no approved treatment for cats.

Fortunately, there’s a way to keep your dog or cat safe: by administering monthly heartworm preventives. Most heartworm medications also protect your pet against other parasites, such as roundworms, hookworms, whipworms, ear mites, fleas, and ticks. We can recommend a regimen of prevention for your pet based on the climate in our area, or for your lifestyle if traveling to warmer areas in our heartworm off-season. For our canine patients, we can offer an in-house blood test to screen for the presence of heartworm.