I did most of 5 years in the scruff, though more properly just back of the shoulder blades. That's where Neko's long hair was shorter and she didn't mind it. I tried elsewhere, she was not a fan.
I've been meaning to pop in and comment on the ultrasound results that Bhooma tagged me on. But it's been a very busy week. Taxes.

And the electric company had the power out yesterday. Anyway, I'm back.
The ultrasound results sounds like it could be IBD or SCL (small cell lymphoma). How has Raven's weight been trending the last few months? I'm glad to hear his GI issues seem to be resolving now with the new diet. Some vets will try a novel protein diet first and see how it goes, before going to biopsy if novel protein diet doesn't work.
I'm going to disagree with this statement:
so that you know, biopsies are NOT necessary to treat. IBD and small cell lymphoma are treated the same way - with steroids and sometimes chlorambucil.
OK, it's the wording, you don't need a biopsy to treat, but you do need a biopsy to diagnose what you are dealing with and what is the proper treatment. The treatments for IBD and SCL are NOT the same so it is good to know what you are dealing with. SCL treatment starts with steroids, IBD might but also might be controlled with just a novel protein diet and probiotics. With SCL you can start to taper off steroids after clear remission whereas for some cases of IBD, it continues to be always needed. Chlorambucil is part of SCL treatment, but only for IBD if severe. Since it's a chemo drug, and potentially carcinogenic, you only want to give it if you have to. I'm on my third cat with a SCL diagnosis, this last one has both IBD and SCL, diagnosed 5 years ago with IBD and emerging SCL. You are lucky that Raven is responding well to the novel protein diet. That can be a clue that IBD is part of the picture, and hopefully the only thing in the picture.
Does that "custom" in your signature mean custom dosing? Just curious as I didn't see anything else that could refer to how you are changing doses.