Hello! Sully is my first smaller dog. I have had lots of labradors, a Brittany Spaniel, English Springer Spaniel, etc. I know from those experiences that most people recommend to wait until the dogs is more fully developed (12-18 months) before neutering. I recently asked my vet about this with smaller breeds. She looked at me like I was nuts. She did not think that was necessary, even for larger breed dogs. What are your thoughts? What age did you neuter your Cavalier??? =) I'm not in any hurry, just wondering what the thoughts out there are. Sully is 4 months old now.