It only takes 1 infected mosquito to give your pet heartworms. Fill out the form to get your coupon and protect your cat or dog from deadly heartworms. Valid at participating Banfield hospitals in the U.S. and Puerto Rico. They are located inside select PetSmart stores. Valid for new and existing clients, except pets already enrolled in Optimum Wellness Plan with parasite control option. One coupon per pet. Cannot be combined with any other offer. Veterinarian approval required; exam and/or negative heartworm test required (at additional cost). Can be multipacks of Trifexis, Tri-Heart Plus, Revolution, or injectible ProHeart 6.