Heartworm preventions are 95% effective or more if administered properly and given regularly.

Typically, there are some pills that you can give kitty cats like you do dogs, that are labeled for a cat but are a bit different. There are also topicals. The vast majority of people use the topicals that you put on the skin. These prescription medicines prevent the dog or the cat from getting infected, to begin with. That's the key with a cat, to prevent them from getting infected.

No, because they don't have microfilaria, we can go ahead and put them on preventatives. They so rarely test positive because they almost never get adult worms, so yearly testing is not recommended.

We only recommend testing when we think the cat has heartworm. Routine testing is typically not done, probably because there's no treatment for it once the cat has adult heartworms. They don't have microfilaria, which is the baby warm circulating in the blood, so all heartworm preventatives are safe for them. We recommend prevention in cats. In a symptomatic cat, a sick cat, and we suspect heartworms, then we’re probably going to get an x-ray, we screen for antibodies. And do the ELISA antigen test as well.

Typically, if we suspect a cat has heartworm, we will recommend a test just like in a dog. Most of the time, it comes out negative because, once again, that test tests for adult heartworms, which it's not usually adult heartworm that causes a problem in a cat. There aren't tests out there for immature stages. We sometimes test for antibodies. However, though they can develop antibodies a couple of months after infection, they are very transient. They go away really quickly, so we have a short window to catch them. That only means exposure and not necessarily that the cat is continuing to be infected as well. We will often look at x-rays, and we can see changes in the lungs that are highly suspicious of heartworm.