I was coming back from home in the car. I got in the house and when I opened the door my dog went out to greet me. The neighbors dog was in my garage and they started fighting. I immediately took them by their collars and that is when the neighbors dog bit my arm. It was a pretty bad injury that bled heavily and required stitches. So I went to the hospital to get it checked out and got stitches. I didnt think much of this episode until today, months later. My concern is that the neighbors dog could have previously bitten a delivery guy right before I got to the house. I dont know if this happened but I worry about the possibility that it might have, which would mean the dog would have bitten the other guy and a few minutes later would have bitten me. Is this something I should worry about as an hiv risk? There has been a proven case of transmission through a dog bite in África, but it was one bite right after the other, which I guess was not my case as I did not see anyone being bitten immediately before me and the two dogs were fighting right before biting me so there was also a chance any blood will be dry

Welcome to the Forum.  Thanks for your questions.  I'll be glad to comment.  I was able to find the report of possible transmission through a dog bite which occurs immediately following the dog biting another persons with untreated HIV.  As the authors report such an event is extraordinary and I would rank the probability of this happening to to you from the situation you describe as being less likely than you being struck by lightening.  After all:---

Thanks so much, doctor. That was my logic and just wanted to double check with you. Just to confirm.... I was calculating the minimum time it takes for me to get in the garage and house and it would at least be a minute and and 15 seconds between episodes (in the unlikely scenario that the dog bit someone else), so that would be enough and means the virus would no longer be viable, right? Thanks already!

If anything, I think your estimates if time are, if anything, too short.  We agree that you are not at risk.  EWH---

Thanks a lot, doctor. I guess trying to estimate the exact time is irrelevant. The point is that since there was no other person with me when my bite happened it was definitely not a matter of seconds, but at least a minute or 2,  so it cannot be considered an immediate and succesive 2 person bite episode, and therefore, it is not a risk, as the virus exposed to air, becomes non infectious, right? 

You are exactly right.  I really would not worry and encourage you to move forward from here without concern.---