What are heartworms and why do I have to test for them yearly?
Heartworms are parasites that are injected directly into the bloodstream by mosquitoes. They mature and move into the heart where they can cause serious damage. Oklahoma generally has a mild winter so the mosquito population does not always disappear in winter months. Year round heartworm preventative is necessary. Even though your dog is on heartworm prevention, it is still a good idea to test for heartworms annually. Your dog may have spit out or vomited their pill when you weren’t looking, and occasionally pills are forgotten.
