Canine diabetic neuropathy/ MELLITUS?

Papillon/Fox Terrier cross breed.

My girlfriends 3.5kg, 8yr old dog seemingly has Diabetes Mellitus &/or diabetic Neuropathy symptoms... excess weeing, drinking, weight difficult to gain, involuntary legs spasm etc. We noticed her 'involuntary muscle movements' (front legs only) over a yr ago and she was diagnosed as being epileptic due to what we thought at the time was spasming (of the front legs) as she would suddenly seem to lose muscle control, become a little unbalanced, raising one FRONT leg at a time and leaning against our other dog to keep upright. I stress that this was only in her front legs and only once, (over a yr later) last night have her back legs ever seemed to be affected. As directed by the vet a yr ago we took her off the epileptic meds to see if she'd improved and cut out all scraps and long walks as we deemed these the cause of her 'fits'.

Until last night she's been 'spasm-free' however in a state of excitement (dinner time) her front legs both seized up... lifting towards her head and her rear legs were a little wonky as she tried walking. She was totally responsive and still only had eyes for her dinner. Her breathing and heart rate also seemed as normal as I could tell.

We have been feeding her the occasional treat again lately so i assume this has set it off, however her nightly wees are larger than ever (the size of our 25kg staffys!) and we're uncertain of what to do. My main question before we go taking her to the vet is, has anyone had a diabetic dog with similar Neuropathic symptoms, especially the front legs as this seems almost unmentioned in all cases I've searched... Many thanks, from concerned animal owners and our little Roxy :)