How Does Heartworm Preventative Work?

You’ve been giving your beloved furry best friend heartworm preventative for quite some time, right? But have you ever wondered how it actually works?

Contrary to what you may think, heartworm preventatives do not actually stop the infection from occurring. Heartworm medications kill the larval heartworms that have made it into your dog’s body during the past month. This is why it is crucial that heartworm preventatives be administered strictly on schedule according to its instructions. Unfortunately, these medications will NOT kill adult heartworms that are already present in your dog’s body.

Heartworm preventative can be administered topically, orally, or through an injection. The active ingredients in monthly heartworm medications kill any larvae that may have been in the system for the past 30 days, they do not actually stay in the bloodstream for thirty days. It takes longer than 30 days for the larvae to develop, therefor medication is only needed once a month.

In order to buy heartworm preventative, you must have a prescription from your veterinarian. Your vet will also require that your dog be tested for heartworms prior to taking the medication. If your dog has heartworms, taking the preventative can actually be life-threatening.

For more information, talk to your veterinarian.