Is it okay for me to turn in my neighbors for having dogs?
Do they have too many dogs?
Yes, it can be disturbing and can be a safety risk.
If they are breaking the rules and you feel that they are disturbing you and are a safety risk then do what you have to do. Try to put yourself in their shoes however and do your best to understand the reason why they may have all those dogs.
Nah, I'm going to do it. I don't care if they have reasons.
If you think that what you're doing is for the best, and they're breaking some kind of rule, then I think it's fine that you turn them in. Rules are there for a reason, and if they're flaunting the rules then they shouldn't be surprised if they have to face the consequences.