Why does my dog need an annual heartworm test if they are on heartworm prevention year round?
As with any preventive medication, nothing is 100% effective. By testing every year, we can make sure that the medication is working. Dogs have been known to throw up the pill and/or spit the pill out once they get outside or behind the sofa. Sometimes our lives become very busy and heartworm prevention may not be given for a month or two. If we do not test your dog and they do have heartworms, the monthly preventive could cause a serious reaction and even death. We use a heartworm test that tests for two tick borne disease, one of which is Lyme disease.
