My cat has crystals, is hungry, and spits out her medicine. What to do?

I would strongly advise against this. I would keep him on some form of food labelled for urinary crystal prevention. Urinary blockages can be a fatal emergency. Royal Canin, Hills, and Purina ProPlan are the three foods that use the most science in their nutrition. I have never heard of young again. Any of their foods that are labelled "S/O" are meant to prevent the formation of urinary crystals. Many urinary diets do have an increased caloric amount, and I sympathize that can be a struggle, but it is related to what keeps their urinary tracts healthy. You can try feeding canned food that is watered down to lower some calories. The extra water and hydration is great for the urinary tract as well. Feeding the food out of toys and feeders, instead of bowls in meals, to encourage their working for food and hunting behaviors can also help with their food intake.

The best way to maintain his weight at 12 lbs is to measure his food and count the calories. A typical 12 lb cat should eat about 230 calories total in a day. Look at the calorie content of the food your vet prescribed and feed based on the calories per cup or per can. It is probably fine to switch to urinary care with weight management but you should check with your vet first since it is prescription diet. I would also recommend asking your vet about feeding some canned urinary food as most cats with crystals should be fed canned food, too.

You can try warming it up or mixing in a tiny bit of plain baby food. Since Gabby does have a history of urinary obstructions, discuss surgical options with your veterinarian. A perineal urethrostomy (PU) can be performed to widen the opening through which he urinates to prevent blocking.

Surgery may be the next option if he won't eat the prescription diet. Discuss other diets, both canned and dry, with your veterinarian first. It may take several weeks to months to fully dissolve any stones or crystals. Try to get him to drink as much water as possible to dilute his urine.

Any wet or semi wet food that he likes such as liver pate, sausages, sardines and just regular wet cat food. With the syrup I would advise giving it to him directly in the mouth as it can affect the taste of the food greatly.

I'm sorry to hear that Cassie isn't feeling well. The fact that she is showing interest in her food, yet dropping it, makes me question if she has some degree of dental disease causing pain in her mouth. That said, if she has a mass in her stomach, this could also be impacting her appetite and ability to comfortably eat. Getting cats to take medication can be tricky, but this article has some good tips for giving medication: https://www.petcoach.co/article/how-to-give-your-dog-a-pill/. If you have liquid medications, follow the steps for giving a pill, but squirt the liquid to the back of the mouth instead of placing the pill there. If this issue persists, I recommend taking Cassie back to her vet for further evaluation. I hope that she's feeling better soon!

No, that isn't enough food for her. I'd take her back into the vet to see if she can get some medication to stimulate her appetite. You may have to pill her yourself in order to give her the medication. Check out this video on how to do it: https://www.youtube.com/watch?v=HB_cxAIcuMc.