My 8-year-old cat has seizures, weak, confused. Need diagnosis help.

I’m sorry to hear that Kiri has been so sick. Ear mite infections will not cause the severity of the issues you’re seeing at this time. Lasix is a diuretic used to remove excess fluid build up - typically from heart disease. Increased water consumption is a common side effect of this medication. Without having examined Kiri or seeing any test results (including blood work, a urinalysis, and even x-rays), it’s next to impossible to provide an accurate idea as to what may be causing this signs, as there are too many possibilities. For instance, autoimmune disease, cancer, toxin exposure, or various infectious diseases could all cause these signs. In order to comment on your vet’s treatment recommendations, I’d first need to know the cause of these signs. At this point, it sounds as though extensive further diagnostic testing is needed. I hope that everything goes well!