If It's OTC....it ain't the real deal

There is a reason why heartworm prevention must be bought from a licensed veterinarian - that reason....it's a medication (ie a drug). The Food and Drug Administration oversees prescription medications dispensed by veterinarians and therefore the label for heartworm prevention states that it must be prescribed by a licensed veterinarian. What does that mean.....if you are buying something OTC (over-the-counter), ie. Frontline or Hartz or Advantage, then it is NOT a heartworm preventative. Yes they may state on the label that they prevent mosquitoes but they are not preventing heartworm disease.

Whether you choose to purchase a topical product (ie. Advantage Multi) or a chewable tablet/pill (ie Interceptor Plus or Heartgard Plus) or an injectable heartworm preventative (ie Proheart 6) -  all heartworm prevention works in the same way. They are designed to eliminate the immature (larval) stage of the heartworms. This includes the infective stage that the mosquito deposits when it bites but also the larval stage that develops over the next 30 days.  That being said, it only takes 51 days for a heartworm to mature to the adult stage and our monthly heartworm prevention is no longer able to eliminate this form. This is why keeping your pet on a monthly heartworm prevention (or every 6 month in the case Proheart6) is so important!

The nice thing about most heartworm prevention these days is it is multi-purpose - being it does more than just eliminate heartworms. Most products are also labeled to eliminate intestinal parasites such as roundworms, hookworms, whipworms, and even tapeworms for some products. Some all in one products may also prevent fleas however it is important to discuss this with your veterinarian as some products may not kill fleas but rather prevent them from breeding.

Just remember - if you can buy it without a prescription or without seeing your veterinarian, then it isn't heartworm prevention!