I think this MIGHT pin down the problem.
You have used it as:
string[] validDogBreeds = new[] { "Bull Mastiff", "Bulldog", "Bold","Beby","Baby","Ban","Bunch" };
It should be:
string[] validDogBreeds = new string[] { "Bull Mastiff", "Bulldog", "Bold","Beby","Baby","Ban","Bunch" };
I guess initializing the string with the new operator was the problem. Let me know if it works. :)