Bulldogs World

I have quite a bit of experience with many different bulldog medical issues but this was something I have never seen or to my knowledge heard about before. -

It is kind of hard to accurately describe. 

Very late last night I was getting ready for bed and Harley was laying on the floor by my computer. I went to bathroom and Harley is always then waiting at the door so he can follow me into bed.  

Last night he didn't do that.  When I went to check on him he was still laying on the floor in his room.  I thought that was weird and turned on the light to check on him.  He was awake but when I called him he wouldn't move.  I then noticed his penis was about 1/2 - 3/4 erect.  It seemed darker and larger around than normal erection and was (for lack of a better description) pulsating.  I then saw that with each pulsation what appeared to be urine was dripping out.  Along with his penis, his rectum was also pulsating seemingly totally out of his control. While this was happening he seemed to not be able to get up and move. His face looked very strange, kinda like he was dazed.  Not sure if it was from pain, or he was also scared.  Harley will typically stop in his tracks whatever he is doing if offered a carrot.  I tried a carrot - he didn't move.  Got my husband up saying something was strangely wrong with Harley.  He layed beside him for a few minutes all the while the pulsating continued and he would not move.  After about 10 minutes (while I was frantically Google searching for anything that sounded like this) he got up, went outside and peed and when he came in he seemed fine.  

We are completely perplexed.  What could have caused this?  

Today he has been completely normal.  I did call our vet but missed their return call this afternoon and will talk with them tomorrow.  

If anyone has experienced anything similar to this would really appreciate your input!