I am often asked if it is okay to give the monthly heartworm preventative every 45 to 60 days. When I ask the pet parent why she/he would want to do that, her/his answer is she/he read on the internet that it is safer to give a heartworm preventative every 45 to 60 days rather than every 30 days.

Unfortunately, this information gleaned from “Dr. Google” is totally incorrect and dangerous! The monthly heartworm preventative we prescribe only lasts in a dog’s or cat’s body for one to two days, not 30 days, due to the lifestyle of the heartworm, it is only necessary for the pet to take the heartworm preventative every 30 days. Since the medicine already left the pet’s body when the next dose is due to be given, waiting every 45 to 60 days makes no sense from a safety perspective. However, due to the heartworm life-cycle, it is likely that giving the medication every 45 to 60 days, rather than every 30 days, will allow immature heartworms to develop into adult heartworms. In other words, heartworm prevention medication is not effective when given every 45 to 60 days.

As I mentioned in previous blogs, if a pet develops heartworms, while taking the monthly heartworm preventative purchased from our hospital, the drug manufacturer covers the cost of treatment due to their guarantee. However, this guarantee does not apply if the medication is given every 45 to 60 days.

One of the reasons you chose us for care is because you are concerned about your pet’s safety and desire to not over-medicate your pet. We share that desire with you and will only prescribe medication if we feel it is safe to do so.

To schedule your pet’s heartworm test and/or to pick up heartworm preventatives give us a call at 972-867-8800 and we will be happy to assist and help keep your pet safe!