April is Heartworm Awareness Month, and here in Florida, heartworm disease is something we diagnose far too often. Because mosquitoes are active year-round in our warm climate, pets in Florida are at high risk for heartworm disease — even if they live mostly indoors.

What Is Heartworm Disease?

Heartworm disease is a serious and potentially fatal condition caused by a parasite spread through mosquito bites. Once infected, worms live in the heart and lungs, causing damage to the heart, blood vessels, and respiratory system.

In dogs, heartworms can grow up to 12 inches long and live for several years. In cats, heartworms are fewer in number but can cause sudden and severe breathing problems.

This disease is known as Heartworm disease, and it is almost entirely preventable with monthly prevention.

How Do Pets Get Heartworms?

1. A mosquito bites an infected animal.
2. The mosquito picks up heartworm larvae.
3. The mosquito bites another pet and transmits the larvae.
4. The larvae grow into adult heartworms inside the pet’s heart and lungs.

Because mosquitoes live indoors and outdoors, indoor pets are still at risk.

Signs of Heartworm Disease

Many pets show no symptoms early on. As the disease progresses, signs may include:

• Coughing
• Exercise intolerance
• Fatigue
• Weight loss
• Difficulty breathing
• Collapse (in severe cases)

Cats may show:

• Vomiting
• Coughing
• Asthma-like breathing
• Sudden death in severe cases

Prevention Is Easy — Treatment Is Not

Heartworm prevention is safe, simple, and much less expensive than treatment.

Common heartworm preventives include:

• Heartgard Plus
• Simparica Trio
• Interceptor Plus
• Revolution Plus

These medications prevent heartworms when given every month year-round.

Why Annual Heartworm Testing Is Important

Even pets on prevention should be tested once a year. Reasons include:

• Missed doses
• Vomiting medication
• Spitting out medication
• Product failure (rare, but possible)
• Ensuring prevention is working

Heartworm treatment for dogs is expensive and requires months of restricted activity. Unfortunately, there is no approved treatment for heartworms in cats, which makes prevention even more important.

The Bottom Line

Heartworm disease is:

• Dangerous
• Expensive to treat
• Common in Florida
• Almost 100% preventable

The best thing you can do for your pet is:

• Give heartworm prevention every month
• Test yearly
• Keep pets on prevention year-round

If your pet is not currently on heartworm prevention, Heartworm Awareness Month is the perfect time to start.