Heartworm Disease in Dogs

What is heartworm disease?

Heartworm disease is caused by parasitic worms that live in a dog’s heart and blood vessels, leading to serious damage over time.

How is it transmitted?

Spread only through mosquito bites
Cannot spread directly from dog to dog
⚠️ Even indoor dogs are at risk

Do we have it in Western New York?

Yes—100%.
Anywhere mosquitoes exist, heartworm disease exists too.

What signs will my dog show when it gets infected?

Early stages: No symptoms
It takes about 6 months after infection for worms to mature

As disease progresses, signs may include:

Coughing
Tiredness (lethargy)
Difficulty exercising
Weight loss
Decreased appetite

Eventually, it can lead to heart failure

Is it fatal?

Yes.
Untreated heartworm disease is fatal in dogs.

Can people get it? What about cats?

Humans: ❌ Cannot get heartworm disease
Cats: ⚠️ Can get it, but it’s less common and different than in dogs

How do you test for heartworm disease?

Simple annual blood test
Detects proteins produced by heartworms
Highly accurate

Do I have to test every year?

Yes.

AAHA and the AVMA standards of care recommend annual testing. The sooner we know about the infection, the easier it is to treat.

How do you prevent heartworm disease?

Monthly preventatives such as:

Revolution
Trifexis
Iverhart

These medications:

Kill immature (baby) worms
Prevent infection from developing

Can't I just give the preventatives to my dog if/when the test comes back positive?

❌ No
Preventatives only work on early-stage worms
They do not kill adult heartworms

What is involved in treatment of the disease?

Treatment is more complex and includes:

Diagnostic staging
- Blood tests
- Chest X-rays
Treatment phase
- Series of injections
- Possible side effects
- Often requires hospitalization

 Key takeaway

Prevention is much easier, safer, and cheaper than treatment.
A simple monthly medication and yearly test can protect your dog from a life-threatening disease.