We just encountered this with our dog chewing on a shrub called
Mockorange. We ended up taking our dog into the Vet after noticing Her vomiting blood. After prescribing three different medications and other things performed in there office she was sent home. The Vet had us watch her close for the next three days and the vet called daily to check on Her progress.
She did not actually chew the bark of the shrub but there were pods dropped onto the patio that she picked up in her mouth and we suspected this to be the cause. Since this experience all poisonous shrubs have or are currently scheduled for removal.
Just our experience and thought we would share it since it was mentioned on this forum.