Could be anything Skippy, I am sure its just an off day, our cats get them sometimes. Once Syra seemed really ill, she was about 4 weeks old. she didnt seem to have control over her body, when I put her down she just fell forward. We lay her in a basket, thinking, this is it she is going to die, it was too late to phone a vet....My daughter sobbed as it was the first time I had let her do the feeds as I wanted to go shopping. Next morning she was fine, her old self running round, we dont know to this day what happened. I thought it might have been a fit as she was kind of post epleptic. Anyway, she never had any more of these and the vet said she had s slight heart murmer when she was speyed. They can scare us stupid. I hope he will be fine when you get home, just make sure there isnt any rat/mouse poison anywhere around the area. They generally dont touch the no no plants, so my vet said.