Oh gosh, so sorry to hear this about your little guy. He's dealt with so very much.
Two of my yorkies had IVDD later in life and it's not uncommon. This is diagnosed via xrays - so has his spine and neck been xrayed...? Once confirmed, the dog can go in and out of IVDD 'flare ups' - where symptoms can be present - you treat them - and they may go away for a long time.
To me, it sounds like your baby is in pain and not wanting to eat bc of that. For bad flare ups, the standard treatment is usually prednisolone (anti inflammatory, helps a great deal), methocarbamol (which you have), gabapentin, and Tramadol for pain.
If that regimen doesn't work well, then I'd definitely see a Neuro -- or see one either way so that you can get a more specific assessment by a specialist.
For my Marcel, we did acupuncture and cold laser therapy and it helped a great deal.
Please keep us posted!
__________________ ~ A friend told me I was delusional. I nearly fell off my unicorn. ~
°¨¨¨°ºOº°¨¨¨° Ann | Pfeiffer | Marcel Verdel Purcell | Wylie | Artie °¨¨¨°ºOº°¨¨¨° |