Thanks for using Petco Pet Education Center, formerly Petcoach! Loss of appetite can be observed with many conditions such as gastroenteritis, dietary indiscretion, kidney disease, pancreatitis, among many other possibilities. I recommend that you have Darla evaluated by your veterinarian for further assessment and treatment. They would be able to check for these possibilities and others depending on the findings on exam. Treatment would be based on findings. Good luck and have a great day! Hoping for a speedy recovery!