
Get him to the vet. They can be caused by so many things and are a common symptoms in so many health issuses that it could be a large worry or a minor one. My first ever dog, a standard-sized yorkie, had epilepsy and eventually an enlarged heart. From our experiences with him and speaking to our vet, it seems that they would be brought on by either A.) Heat or B.) Over-activeness/Excitement. It was as if he would go in 'overdrive' and therefore we tried to play calming games with him and let him let off energy on gentle walks rather than letting him get off and running around like a nutter, playing with other dogs and getting overexciting as they'd often occur after this.
He had medication for his epilepsy which took about 6 months to get the dosage right. It was horrible at first but eventually he was his normal self just without the fits which would occur about once every month.
When he began a fit we would make sure he was safe from whacking his head on anything and then turn the lights off and leave the room. Calming him down, by speaking to him stroking him, or leaving the radio on would prolong the fit as he would be over-stimulated. Offer lots of water straight after as he was often left dehydrated after his fits from all the panting. It is a horrible experience to see and it will get easier but just make sure you offer water and we found it helped to shut him in the back room rather than at the front of the house if we ever had to leave him for a number of hours in the day. He was a good guard dog and if there were any builders or workmen in the road when we were out the house,he'd get so stressed at trying to get them that he'd sometimes have a fit from being so worked up.
I do not remember the name of the tablets he was on, but they DO help, despite the temptation to take the dog off them when the dosage isn't quite right at first. For a few weeks expect your dog to be drowsy until you have the dosage right.
Josh