SOMETHING SERIOUSLY WRONG WITH OUR DOG

Cassie and I went outside and played with the dog today. He ran around and then stopped to take a drink and very shortly after his drink he started to act like he was going to vomit. He was all hunched over in a U shape. Then, very gracefully, he put his nose to the ground and his front legs and the rest of him followed suit and he just dropped to the ground. He shook a little bit and then I think he tried to get up but was struggling and was waving all four legs around. He was on the ground for a couple of minutes before he could get up. I ran to the house door and hollered for Darren. Darren came outside and when Tucker did stand up, he just stood there like he didn't want to move. He came around, within 5 minutes he was running around again like nothing happened. He has episodes when he eats where he will just pass out and fall over but he normally gets right back up and starts eating again. We took him to the vet for this last summer. The vet couldn't find anything physically wrong with him and told us to try and elevate his food bowl but I think there is more going on. I found this website that is dedicated to Siberian husky health, www.siberianhuskyhealthfoundation.org and they say on the website that huskies have genetic problems and according to the info it might be a thyroid causing his problems. I wrote in at the website about the problems Tucker is having and hopefully they will reply soon. It would kill us if there was something terribly wrong and we had to put him down.