Possibilities include, but are not limited to:- Hyperthyroid (overactive thyroid)- Diabetes- Kidney Disease- Liver DiseaseWith this information - the first step to evaluate underlying causes would be basic bloodwork. We need to look into specific values including:- Kidney- Glucose- Thyroid- Liver- etc.As you have said, those tests were non diagnostic - meaning they do not show an answer as to what is going on - the next test would then be an abdominal ultrasound. Based on the examination and the tests above - either specific treatment or supportive treatment recommendations can be made.With that said - what would I be looking into with the ultrasound? Why do I recommend this? Of course it would be part of a thorough evaluation when there is weight loss such as this - but notably I would be looking to see if there was evidence of intestinal thickening due to Inflammatory Bowel Disease (IBD).IBD is common in middle aged to older cats - as they commonly are thin.
In these cases - we then target the cause - the hypersensitivity to the food - changing their food to either a hydrolyzed protein diet or a novel protein diet.
Other common treatments for cats with IBD including medications such as metronidazole (an antibiotic) and even a steroid (prednisone)
I hope this information helps! Please let me know if you have other questions!_____________________________________________________________________Please click "ACCEPT" if the information I have provided has been of help so I receive credit for my work. Bonuses are always welcome and Feedback is appreciated. Thank you.The above is given for information only. Although I am a licensed veterinarian, I cannot legally prescribe medicines or diagnose your pet's condition without performing a physical exam. If you have concerns about your pet I would highly advise contacting your regular veterinarian.
- A calorie dense nutritional supplement such as nutrical (LINK HERE)- Another option would be baby food. If you are going to try this, please purchase baby food that does not have any ingredients such as garlic or onion.Many baby foods now will only have the ingredients of the item and water...for example chicken and water. But they will not have any other salts or seasonings. This is what you need. Just chicken and water or beef and water
BUT - If this does not help and the signs you report continue, then I would really recommend an ultrasound to get to the bottom of this.