"Yearly heartworm" refers to an illness caused by parasites that are transmitted to animals, particularly dogs, by mosquitoes. It means that these parasites can infect a dog's heart and lead to serious health problems on a yearly basis.
We will be glad to talk to you about the need for yearly heartworm tests in your dog and how you can prevent this fatal disease. (tri-cityanimalclinic.com)
Some companies will guarantee their product providing you use the heartworm prevention year round and are performing yearly heartworm tests. (wpvet.com)
We recommend heartworm preventative for both dogs and cats, as well as yearly heartworm testing for dogs. (woodlandvets.com)