Hi Keith, Welcome to JustAnswer. I'm a licensed veterinarian and I'll be happy to help. I am so sorry to hear about all you have been through with Bella. There are some differences with way your vet is treating pancreatitis than how I would usually treat it, so maybe I'll start there. First of all, pancreatitis is rarely an infectious problem in cats, so the antibiotics are probably not necessary and they could be suppressing her appetite, so I would recommend that you and your vet consider stopping those.
Pancreatitis doesn't seem to be caused by fatty foods as in dogs, so I think that the beef would be a fine temporary diet. . .it's not complete, but temporarily it seems fine to me. It is all important that cats eat, and if this is working for her, then this is fine in my opinion.
I think that your vet is also suspecting IBD (Inflammatory Bowel Disease) since the ultrasound showed a thickened (inflamed) intestine which would be the intestinal wall. For this, it is recommended that cats be put on hypoallergenic diets, prednisolone, and metronidazole. Vit. B 12 injections weekly are also recommended, and Bella was low in B 12 and did receive one injection so far. I'd keep these up weekly.
The Vetergesic is a very good pain reliever for pancreatitis so I'd definitely continue that.
In rereading your post, I see that your vet has diagnosed bacterial overgrowth from Bella's lab results. I see that she has high eosinophils with low albumin. This would support an allergic IBD, but I don't really see anything pointing to bacterial overgrowth and the need for antibiotics. However, I can't say either that there is not bacterial overgrowth, and she does seem to be responding positively to the antibiotics you are giving. . .she is eating, just not the special veterinary diet.
Your vet is probably giving Cerenia injections for vomiting. Cerenia does make a tablet, and the smallest would be 16 mg. The dose is 1mg / kg once daily. For Bella, I'd give her a little less than 1/4 of a tablet wrapping the remaining portion in aluminum foil to prevent exposure and deterioration of the tablet.
I'm going to switch this to the Q&A mode, as this allows us all the time we need to address Bella's case without more charges to you.
Dear Dr Barbara
Thank you so much for your valued opinion. I feel relieved that I can continue with the minced beef steak which is very low in fats <5% mixed with equal portion of chicken. I will gradually add small percentages of the special dietary meats until she refuses. I was worried I was poisoning Bella. I will ask about the hypoallergenic foods. We have just realised one of the tablets we are giving Bella (in quarters 2 x per day) which I thought was a antibiotic is metronidazole 200mg. I will check what prednisolone is and ask about that. Again thank you so much.