A month ago, completely out of the blue, my DDB (rescue and roughly age 5-6) had a seizure. We took him straight to the vet and heart, bloods etc. were clear. We were given diazepam in case it happened again and lasted for 5 minutes or more. This morning he had another seizure which lasted a little over a minute. It took him less than a minute to recover and he was bouncing around as if nothing had happened, ate his food and drank water. He's been fine all day.
The first time it happened I'd walked him first thing in the morning but had been out all day. My late teens son had been home with him all day but wouldn't have noticed his little signs that he needed to go out for a pee. Then yesterday I had gone out last night, getting in after 11pm and I assumed he'd been walked as normal at around 10pm. He didn't give any sign that he needed to go out so I went to bed. We all had a lie in this morning and DH got up at around 9.30 and the dog followed him downstairs and it wasn't long after that he had a seizure.
Obviously we'll keep a record of any more seizures and take him back to the vet if they become more frequent/longer, but my question to those of you with a bit more medical knowledge is could holding on to his pee cause a build up of urea(?) in his bloodstream triggering these seizures? Would kidney problems not have shown up in the blood test?