This means the year round use of heartworm control products according to manufacturer directions and veterinary instructions. (pethealthnetwork.com)
If it is not, then keeping your cat on a monthly flea / tick / heartworm control product designed to also control intestinal parasites is a very good idea. (2ndchance.info)
A popular form of heartworm control, Advantage Multi for Dogs is a once - a-month topical solution, using two different types of medicine to ward off and kill fleas, mites, and intestinal parasites. (petcarerx.com)