Hello, and thanks for writing in.
These symptoms are certainly not normal, but are not specific for an exact problem. It could have been something he ate that is making him act this way (like you said). Sometimes another animal can spook them making them act this way. Or sometimes loud noises, bright lights, or other stimulus can cause behaviors like this. I would watch him closely, and if the symptoms continue for about the next hour, I would recommend trying to have him seen by a veterinarian. They may need to give him something to try and calm him down. You can also try giving a dose of Benadryl (1mg per pound of body weight) to try and calm him down (if he's not on any other medication, and if he doesn't have any other health problems).
I hope this helps.
Thanks for your reply.
Benadryl (diphenhydramine) is an antihistamine that can have a calming or relaxing effect on dogs.
You're right, I can't commit to an exact reason, and as I mentioned above, it could be different things, such as a stimulus of some sort (although it doesn't sound like that is the case from your last reply), eating something he shouldn't have, some type of irritation (about anything). An allergy is possible, but usually doesn't cause this type of behavior (unless it is a true allergic reaction, as some dogs will act agitated in this situation).
You can likely wait until morning if your dog's symptoms do not worsen, but I would recommend getting him checked out first thing in the morning.
I hope this is helpful.