Heartworm Disease and Prevention (Dogs)

Heartworm prevention is important for all dogs. Any dog is at risk for contracting heartworm disease and many effective medications are available to prevent this. We carry Heartgard Plus in our hospital, but other preventatives can be ordered though our online pharmacy

Heartgard Plus will prevent heartworms as well as the intestinal parasites hook worms and round worms. We recommend that you give your pet 1 beef flavored chewable dose every month all year long. In order to purchase heartworm preventative, your dog needs to be tested for heartworm disease annually.

Risks of Heartworm Disease in Dogs


Heartworm disease is usually silent until very advanced. The worms live in the heart but also effect the lungs. If the infection is found early, damage to these organs can be minimal. Treatment to get rid of the worms at an early stage usually leaves healthy organs.

Dogs that have severe disease may have little tolerance for exercise and may cough or pant even at rest. As the infection progresses, changes in the heart and lungs can be irreversible. Infection in severely affected dogs are more difficult to treat because their organs are no longer healthy.

Occasionally, dogs with heartworm disease will show no signs of illness, but will drop dead. Every dog owner wants to avoid that scenario!

How Heartworm Disease is Transmitted


Heartworm Disease is transmitted by mosquitoes. A few days after biting an infected dog that same mosquito can now pass the infection to the next neighborhood dog that it bites.

Because Connecticut dog lovers are now rescuing dogs from Southern states, dogs living in Connecticut are at higher risk since the new dogs may bring heartworm disease with them.

Heartworm infection cannot be detected by blood tests until six months after transmission. If your dog has an unknown history you should have him/her checked when you adopt them and repeat the test in 6 months to insure that your dog is truly heartworm free. 

All dogs should be tested for heartworm disease annually even if they are on preventative to make sure that they are not infected.

Heartworm disease is rarely transmitted to humans.

Cost estimate of Prevention vs. Treatment

Heartgard Plus costs about $80-$125 per year depending on your dog’s weight.

A 4 month treatment plan to treat a heartworm positive dog is about $1050-$1250, if the dog is even treatable. And some dogs have lasting complications from this serious disease.

Bottom line is that this is an easy disease to prevent.