Cat losing weight but eating: What do liver blood tests indicate?

Although we can not prescribe treatment via an online method (illegal with our veterinary licenses), what i can tell you is that an ultrasound can not assess liver function. Ultrasound is just an image so it can tell you size and texture changes to organs and evaluate for masses, fluid, etc. Also the good appetite and energy level are not typical with liver failure. Your cat has elevated liver enzymes and total bilirubin but this does not always mean liver failure. I would try to get better clarification from your vet about what was seen on the ultrasound and were the other organs normal (pancreas, GI tract, etc.). More common causes of these bloodwork changes would include liver/biliary infection, pancreatitis, and underlying GI disease associated with the above. Cancer and certain infectious diseases such as FIP can as well. So options would include additional testing to search for a cause (such as pancreatitis testing, liver aspirates, etc.) and/or symptomatic treatment can be attempted for pancreatitis, liver infection, etc. I hope this helps and thank you for using Petco Pet Education Center, formerly Petcoach!