I had a Borzoi that died of blood clot in the heart. About two weeks prior to her death, she ran into a horse fence, busted up her face good but her gum was kind of purplish color. She got up and felt ouchy and I thought hmmmm, probably got the wind knocked out of her. So I let her rest the rest of the day and in 48 hours, she was fine, no other symptoms. Then she had her spay surgery which may have hasten her death a bit because two days after her surgery, she collapsed and died without any warning. I was sick for days. The vet did an autopsy on her heart and confirmed it and he did sent the heart to U of I to confirm his findings because the breeder wants to know for sure what has happened. Also the autopsy revealed alot of things that I never knew about, several broken ribs, bad bladder and kidneys (because she was a show dog) and it made my vet suspecious of her old injuries as "abuse" which I do not think the breeder ever abused her. Running into fences are so common in Borzois in their tracking trials.
Has your dog ran itself against the fence, chasing after something? Good thing you took her to the vet!
