Whilst exercising my 19 month old spayed lab today (she is quite fit and active) she had a really weird turn which is the first time I have seen it happen to her.
She was being particularly active today racing around more than I would say is usual and then she just came back to me and started to walk with her back a bit arched, she then seemed to get really wobbly and weak in her front legs dragging her feet along the tarmac so you could hear them scuffing she then started to do what I would describe as goose stepping before completely folding at the front end so her nose was on the tarmac with her front legs underneath her although her back end seemed fairly OK (she did appear a bit weak in her hind limbs but her bottom was still skywards) she was a little spaced out just like she had had a sort of faint. We rested for a bit and she seemed to come back to life a bit responding to our voices and wagging her tail at people passing by. When we started walking again she seemed a bit disorientated for just a few seconds and was sort of swinging her hind limbs like she'd hurt her back although she wasn't dragging her front feet now. After about 5 minutes she seemed absolutely fine again as if nothing at all had happened and although I lifted her in the car to come home she jumped out all on her own at home. Could it be she has some sort of heart problem or just over-exertion?

Hi,
This sounds to me like an epileptic fit. Epilepsy seems to be occurring more frequently in dogs now.
It would be as well to get him checked out by your vet.
Medication is available, which usually works very well, but many vets - including myself - think it not necessarily for the best to give a dog medication 2 or 3 times a day to prevent a 'turn' which may happen only once or twice a year.
In other words, subject to your vet confirming my suspicions, I would wait and see how often these turns occur before staring long term medication.
W