I've had 2 dogs with broken toes, and a 3rd who I co-own broke one. The first one was years ago, and it was the middle two toes. The vet casted the foot, and it healed up fine. The next dog broke an outside toe, in that case the vet said to just leave it alone and let it heal, since it wasn't a weight bearing toe. I think they all bear weight, but I guess the middle two bear the majority of it? The most recent dog also broke an outside toe. Once again the vet wasn't overly concerned because of it being an outside toe, but he did put a thick wrap on it, and then rewrap it once a week for 6 weeks. It also healed up fine.
I'm not sure if it would make a difference front vs rear toes, the first and last dogs were rear toes, the middle dog was a front toe.
One of the people on my flyball team has a Fox Terrier who is always breaking a toe (front foot) hitting the jumps, at least once a year, maybe more often. I don't think they do anything for it, the vet says "yup, it's broken" and the owner rests him for a month or so to let it heal, then he's back again.
I'd at least have the vet take a look at it though, depending on the type of break they may need to do something, even if it's just the thick wraps and not a cast.