Is a heartworm test necessary every year?
Testing helps detect infection early before cardiovascular damage is done by heartworms. There is no guarantee your pet ate and metabolized all of it’s pills. Testing is important because administering heartworm preventative can lead to severe illness or death in an infected dog. Cats also get heartworms but testing is not as accurate. Pets traveling to warm weather climates in the winter should receive medication year round and be tested every two years.