My friend came round today with her children and dog Rusty. He's about 5, a rescue, Patterdale cross, typically Terrier like 
. We were all ready to go out for a walk and bike ride with my dd and our dog Alf.
Rusty has recently had two "turns", in the last month, whereby he starts to lean slightly to one side, his whole body seems to stiffen, his head leans to one side and his back leg is out at an angle from his body. He wobbles around, doesnt lie down but seems totally unbalanced and dizzy. He tried to bite anyone who went near him so was obviously frightened and in pain, this is very very unlike him, he is the kindest boy and would not dream of biting normally.
My friend has had him to her vets twice, they have examined him, taken bloods and tested for every eventuality, nothing abnormal.
As we were heading off today, this happened again, it was the first time I had witnessed this and I'm worried about him.
The only way i can describe it, is that it is as if he was having a stroke. That said, this all lasted around 2 minutes, no aggression this time, he hid in between my legs, I stroked him and comforted him and was then he was absolutely back to normal, chomping at the bit to get out on our walk and showed no sign what so ever of this happening. He walked and walked and is now snugged up in front of his fire after eating his supper, just as though he is fighting fit.
He obviously isnt, I have advised my friend to take him back to the vet to ask them for a brain scan. They did advise this if it happened again, we both feel that we have to get to the bottom of this. Hopefully then he can be medicated to deal with the problem.
Has anyone had any similar experiences? Any advice would be appreciated, he's a lovely little fella.