Thank you for the reply.
This is a very common scenario in cats and it is likely that there is disease present, but that it is hiding very well. Most of the time with the symptoms you describe, the most likely location of the problem is the GI tract. Some cats have a low grade flare up of pancreatitis which can be a challenge to confirm as it is not always evident on routine bloodwork. Along with that, many of these same cats also have a degree of inflammatory bowel disease (IBD) or even slow growing intestinal cancer. Unfortunately, either of these can be present and there can be no other abnormalities noted on bloodwork, xray or even ultrasound, although these tests should be run to rule out other conditions that present with the same symptoms. There is a specific GI blood panel that can be requested and if abnormalities noted, can lend support to either pancreatic or intestinal disease. The only way however, to confirm the diagnosis is with a biopsy of the intestine. This can be done via endoscope, but is better performed with an exploratory surgery. The problem with this is that many cat owners are not willing or able to pursue the diagnosis by these means. It is for that reason that many cats are "suspected" to have IBD or GI cancer as the cause of their weight loss and anorexia once all of the other easy to find things have been ruled out.
I suspect that may be where you are at with Daisy. If that is the case, you can discuss with your veterinarian the pros and cons of proceeding with a biopsy to confirm the diagnosis in her situation. Even if you choose to not go the route of biopsy, she may benefit from a course of corticosteroids and perhaps a hypoallergenic diet as sometimes food allergies contribute to the IBD. There are other medications and supplements used to manage IBD as well. Steroids help many cats with either of the two conditions to regain their appetite and gain weight, but if there is intestinal cancer, the result may be short lived. Often times, we are able to manage many of these IBD cats for quite a long period of time and with a relatively good quality of life with medications alone. Work with your veterinarian to decide what is best for you and her, but most likely, there is some therapy that can be offered and hopefully help as least for awhile .
Here are a few links you may find informative.
inflammatory bowel disease (IBD)
I hope this is helpful. Please let me know if you have ANY other questions. My goal is to give you 100% satisfaction and if you are not yet satisfied, please reply so I can clarify for you.
My posted replies are for general education only and not meant as a diagnosis. Only after a thorough veterinary examination can a diagnosis for your pet be made and specific treatments be advised or medications be prescribed.