The DU Lounge

The current strong recommendation (including all of the South and regions of the country where heartworm is highly prevalent, and yes, cats DO get heartworm) is a very broad-spectrum topical product like the one below that addresses earmites, protects against fleas, ticks, and mosquito-born heartworm. You will need a prescription from your veterinarian, but you can usually have Chewy.com or elsewhere call them for a prescription/approval.

I was researching lung nodules in humans for an ER patient recently, and in many areas of the country, after cancer, parasites, including heartworm, pose the second or third most common cause (fortunately detected on thorough biopsies). That had me researching HW in cats and in these same hyperendemic areas, even those cats reported to be indoor-only had a 27% infection rate. So, things are 'a changing with climate change--and broad spectrum parasite control (not just for ear mites) is increasingly necessary. Just wanted to bring this to your attention. My area of Colorado has increased risks as well, but I can guarantee you any cat or dog I owned while living in the South would definitely be on these products year-round.