Clotting factors issue; uncomfirmed cause

[Heiferly]

On Friday 22 Oct. my dog had a procedure to have his teeth cleaned and two small masses removed, from the left side of his face and from his left lateral hock.  The one on his face turned out to be merely a wart, and in any case both were found to be benign.  As they were both superficial, no sutures were required.  There were no clotting problems at the time of the procedure and he went home without issue the afternoon of it without event.  He started seeping small drops of blood from the facial incision (and only that incision) two days later, so we purchased an e collar, presuming he might be scratching at it with his dew claw and opening up the scab.  However, by the following morning (the 25th) there was a very large amount of bright red blood saturating the fur of his head and neck and smeared around the inside of the e collar, so we rushed him back to our vet.  They cleaned up the area, found that the insicion had not been widened in any way, and put in two sutures.  He slept (back in the e collar) during that day, and we did not observe him messing with the incision whatsoever.  Nonetheless, by 5:30, he was soaked with blood again.  We rushed back to our vet and they applied a pressure bandage, presuming again that he had somehow agitated it to cause it to bleed (the other incision was not bleeding at all).  The e collar went back on over that, but it was less than 4 hours before that was saturated and blood was leaking out of the pressure bandage.  (cont'd below)

[Heiferly]

Just bumping my question back up to the front page in hopes that it might get a response.

[Heiferly]

We raced him to OSU College of Veterinary Medicine's Small Animal Hospital.  He was taken in through the ER and while being assessed there, the incision on the leg started seeping blood as well.  They tested his clotting factors (see test results) and he was admitted to the ICU.  Under presumption that the most likely cause was rodenticide poisoning, especially in light of his relatively clean bill of health re: his physical in Sept, he was treated for that with plasma transfusion and started on Vitamin K regimen (minimum 30 days).

My question is that if we are wrong and it is not rodenticide poisoning, what other conditions are consistent with sudden onset of coagulation difficulties such as this (i.e. he was clotting fine on Friday, slowly started to have problems on Sunday, and rapidly deteriorated Monday including likely internal bleeding)?  Of these, which would be left if we rule out any that should have shown up when we ran the the chem and CBC last month?  Of what's left, is there anything that would be simple/inexpensive to rule out, easy to treat/manage/cure, or is everything complex like organ failure and cancer?  The vet at OSU said that the probability is high that it was rodenticide poisoning, but I'm just trying to wrap my mind around what the other contingencies might be so I can steel myself for whatever may lie ahead.