My sister's dog Hutch also has a broken canine tooth. They don't know how it happened as he had it when they adopted him. I doesn't bother him right now, but the vet said that over time it would wear down and expose the nerve and cause him pain. They are planning on getting it capped this year. It is not an emergency as such, but it is probably something you are going to want to watch and eventually get fixed. The good news is that since it is not an emergency, you can spend some time saving for it before you have to have it done (unlike most accidents dogs have). I also think it depends on which tooth it is as to the need to get it fixed (canine tooth) or eventually pulled.

This is only a guess, but my feeling is that some dogs like some people have teeth that are genetically more prone to chipping than others. Maybe that is the issue with Layla.

I'm sure there are people with more experience with this than me - Leo has great teeth and when I adopted Penny Lane, she has several teeth that we had to get pulled - they were completely rotten. She has a canine tooth that we are watching, but the vet thinks at her age we will probably end up having to pull it within the next year or so. My vet told me that a good diet, teeth brushing and bones will prevent any problems with the rest of her teeth hopefully.