Are deer bones harmful for dogs? Or plants?

Long story short, I had a dog that had to be put to sleep because of it's internal bleeding (and would not eat, unless it was human food). At the time, the only explanation we could come up with is that my dog ate a plant that my ex-stepmom put in the house (the vet said the bleeding may have been because of some sort of poisan or so). About a year later, when my brother got another dog, he claimed that it was because of the deer bones we fed him at the time (he claimed it was also harming his new one). Which makes me wonder, could either of these be an actual cause of internal bleeding? Or is there maybe some other cause of it?