Just seeing this now. Prayers from RI for MOFF and Grandma.

I have never had a cat eat the vet KD food, either, lol.

Thyroid meds, yep, I have had good success with those, and with appetite stimulants.

I find the cat will take the grain free canned food, the one in a gel NOT the one in gravy. Once they have kidney and thyroid issues, I found the gravy just went right through but the gel seemed to help the cat hold fluids. Weruva, Tiki Cat and Fussie Cat are the brands I've used. My cats love the Weruva Marbella Paella.