Summer is here and the chances of your best bud getting heartworm disease is increased. I have had to treat a rescue for heartworm, and we had a dog in clinic today for treatment. Treating HW is not fun, it can kill your pet, and it is EXPENSIVE. HW preventative is cheap. PLEASE consider having your dog HW tested and make sure you use the preventative your vet recommends, and some have ingredients that certain breeds are sensitive to.