[Blueheeler1]

Our family dog, {Paco de Lucia}, of 15 years started to experience moderate to severe nosebleeds about 2 months ago. We are distraught and I was wondering whether or not with my detailed symptons description anyone could offer any further insight into possible causes.
The bleeding started on a trip to Mexico and began rather abruptly with no warning. His first bleeding incident was a rather extreme one and he lost alot of blood which made me fear that he might experience volume shock due to the quantity of blood loss. Since the first incident it has been reoccuring rather consistantly around once per week. The subsequent bleedings have been less severe with the exception of one other major incident around 10 days ago. With every bleeding he sniffs (or maybe sneezes?) making me suspect some sort of nasal or respiratory inflamation/irritation. I've done some research and I guess the next step is to do a blood analysis to narrow down the possible culprit. He has always been energetic and alert but since the nose bleeds has been quite a bit slower and more lethargic.
I was wondering whether any knowledgeable person would be able to tell me anything more conclusive based on the symptons and frequency of the problem. We would be heartbroken if he needed any sort of invasive surgery as he is very sensitive and is in his later years(although still full of power and life).
Much Obliged,
Blue heeler lover in Colorado