This has happened only once to my 10-year old chihuahua-pomeranian. It freaked me out, but I still don't know for sure what caused it. I found some information online that indicated muscle spasms can be caused by a calcium deficiency, so I increased the amount of bone in his diet (I feed raw), and it hasn't happened again (but that could be pure coincidence, as the information I found indicated that the only effective immediate treatment for a calcium-deficiency spasm was intravenous injection of a calcium supplement). I hadn't been giving him as much bone before, because he has only about six teeth, but he seems to be enjoying the extra chewing. You could consult your vet, and/or examine the calcium levels in the food he is getting.

Ebenezer answered on 1/8/09. Helpful? / 0