My vet recently recommended that I switch my dog from Heartguard to Heartguard Plus. Is the “plus” really better at preventing heartworm?

Sam
Stateline, NV

Although the manufacturer (Merial) of Heartgard (sic) and Heartgard (sic) Plus does not know how to spell the word “guard”, both products are highly effective at preventing heartworm disease.

The products contain the same anti-heartworm medication at the same doses. The plus product also contains a medication to prevent and eliminate certain intestinal worms. Because some intestinal worms can spread from pets to people, many public health experts recommend using the plus product for both canine and human safety.

Both products have good safety profiles, although Collie breeds may be especially sensitive to side effects from heartworm preventatives. Owners of Collies or Collie mixes always should talk to their veterinarian before starting heartworm medications. In my experience side effects are extremely rare, even in Collies.

The success of Heartgard and Heartgard plus has inspired a pair of copycat products with identical ingredients but different misspellings: Iverhart (sic) and Iverhart (sic) Plus. I don’t know why companies think it will be profitable to mess up the spelling of simple words like heart and guard.

Several other heartworm preventatives are available for cats and dogs. Interceptor and Advantage Multi are two of the most commonly used. Both of these medications eliminate some types of intestinal worms.

In my experience all of the medications mentioned in this article generally are safe and effective. Sam, although your dog’s new medication will not have added heartworm efficacy, the broadened spectrum of the product has the potential to benefit him and you.