What Types of Worms Does Heartgard Kill?

Heartgard is a medication made specifically for dogs to prevent heartworm infestations. It is not intended to kill the adult worms of any kind in an infected dog, but to prevent worms by killing the larvae.

Active Ingredient

Heartgard contains Ivermectin, a common worming medication used in cattle, swine and horses to control most types of intestinal worms; in dogs the medication is used to prevent heartworms.

Prevention

The dosage of medicine in Heartgard is very low and is targeted specifically at prevention and not at treating an already infested dog.

Considerations

A dog that is already infested with heartworms must be treated for that first, and then a preventative such as Heartgard can be used.

Alternative

Heartgard Plus adds the medication Pyrantel to the Ivermectin and helps control roundworm and hookworm in dogs as well as protecting against heartworms.

Warning

While the active ingredient in Heartgard, Ivermectin, can be used to kill other intestinal parasites, it must be done under the direction of a veterinarian. Ivermectin can have serious side effects, and some breeds of dogs like collies and sheepdog breeds are particularly vulnerable to a side effect called ivermectin toxicity.

References

• Marvista Animal Medical Center: Pharmacy Center: Ivermectin
• All About Puppies: Heartgard Plus Worm Control
• Worms in My Pet: Heartgard vs. Heartgard Plus