Last night Dobbie started to stand up (in the living room) and stumbled, then kind of hunched over (like he was going to take a poop), he then tried to run through the dining room (hard wood floors), through the kitchen and out the back door, down the porch steps and into the yard, he stumbled, slid, fell and wobbled (like he was drunk) several times, he finally laid down in the grass panting. He then tried to get up and stumbled into the fence, then he tried again and laid on his outdoor bed, panting. He didn't respond to my calling his name, but he didn't object to my touching him either. After 5 minutes or so of laying on his bed he stood up, wagged his tail and seemed just fine for the rest of the evening and today. He ate his normal dinner last night before this incident 1 cup of dry lamb and rice kibble with a couple of tablespoons of lamb & rice wet food (he gets this meal 2 times daily) - the lamb and rice diet is mostly because my old scottie is allergic to flour products and it is easier to feed both dogs the same food. There isn't any poison around that he could get into, and his tongue was normal looking. He had been barking & whining excessively at the neighbor's cat (running from window to window and tracking the cats progress across our yard) about 5 minutes before he laid down in the living room and then tried to get up. He is up to date on his shots and otherwise has been a very healthy dog. Was this perhaps a seizure? or a stroke? He is not obese, but might be a tad overweight. Any idea what might be going on?

Optional Information:
Age: 2; Male; Breed: English Shepard

Already Tried:
His breed is UKC recognized not AKC, it is similar in size and temperment to a border collie. I have not tried anything, he seemed fine last night shortly after the incident and this morning before I left for work.