In the South also, and the cat problems here are many. We’ve learned to carry a triage kit with us which includes flea meds, antibiotics, etc The best tool we have is Ivermectin. It’s super potent so one needs to be very very careful.

We put 3 tiny tiny drops from a diabetes needle syringe into their food. It can also be applied topically. This is affordable and will kill mange, ear mites, worms etc (not fleas or tapeworm).

Durvet Ivermectin Injectable 50 mL 50ML https://smile.amazon.com/dp/B07CVMY79R/ref=cm_sw_r_cp_api_glt_fabc_9YQ2SP3NDGE53Q2696A2?

Here is a link to topical application instructions https://www.showcatsonline.com/x/ivermectin-dosing.shtml