Pepper, my 16 year old foster, had to be rushed to the vet's late this afternoon. She had vomited several times this morning and seemed a bit under the weather, but after being sick again this afternoon she could no longer walk, was trembling significantly, and showed no response to my voice. She also cried when I tried to get her up, using a sheet to assist with the back legs.
She was xrayed for bloat, and it wasn't that. Her chest xrays were also fine though her heart is racing (160!); her temperature is normal. Sad girl, they are keeping her there, on fluids, to see how she does.
The only big question mark was a new bag of dogfood I just opened for her - I had gradually been switching her over to it, over the past couple of days, and this morning was her first 'mostly the new stuff' meal - 1/3 her old food and 2/3 new. When I googled the brand, which is a good quality food, I was surprised at the number of reports I found of dogs exhibiting the very same symptoms after eating from a newly-opened bag. (My dogs don't get the same stuff, so they aren't affected by it). Of course, it could be something else entirely. Time will tell.
Meanwhile, healing and comforting vibes for Pepper, please.