This dog needs to be seen by a vet again. Epilepsy has a wide spectrum of severity, if indeed that's what it is. Fits which are becoming increasingly frequent should be investigated and potentially treated. While there may be a link to some trigger when he stays with you, it's likely to be more important to control the fits right now than it is to identify the trigger. Fits can be very mild but they can also be catastrophic if not controlled.
Are you saying that this young dog is now fitting on a regular basis? If that's the case he needs to be taken back to the vet again for further investigation. It's possible he will need regular medication.
Hi ....a young hound who has had two fits in the last year . Fairly mild but the usual paddling legs and out of it zone for at least a minute . Recovery after maybe five minutes . Seen by vet last time and all bloods ok . Now this seems to happen when he is with me as granny carer . I feed him the same etc .....keep his routine the same . Any ideas why ? thank you