The ingriedient Xylitol which is in many Sugarless gums and dental products can be toxic to dogs. The vet told me as few as 5 sticks of gum could have killed my 52 pound bulldog, so wanted to makl people aware because I had no clue.
http://www.snopes.com/critters/crusader/xylitol.asp
I just found this out when my bulldog ate a pack of gum. Luckily he didn't chew the gum with this Xylitol, so he just got an upset stomach and sick, but livesd through it.
I will research later what gums and products have this ingredient so we can all avoid them that have dogs. Anyone finds them please post a list.