
Hi chip
If all breeders culled Chihuahua pups with open fontanel I guess we would no longer have the breed. Have to say that I have never heard anything so preposterous!!! :-(
I do know of certain lines, where the fontanel is still open as adults, and, if I'm totally honest, I feel that folk shouldn't be breeding from adults with open fontanel. Please can I say that this is
my opinion.
I really haven't had an adult that I have bred myself, that has still got open fontanel, so I am giving this reply based on my own experience. I don't know if some lines are affected more than others.
I have, in the past, bought in a bitch with a larger than average open fontanel, and at 3 years old, it has never fully closed. She is still with me, and has never been bred from. I had her spayed after her first season.
I have never yet (with fingers crossed) bred a pup that hadn't closed by 6-8 months of age. Although I have bred another breed many moons ago, I am relatively new to the Chi, approx 6-7 years now. I did talk this through with my vet when I was considering breeding a new breed, and, daft though it may sound, used to get him to check how open they were as pups, until I got the hang of it!
All Chi breeders are going to feel differently, and I am just giving my view on things, as I would never assume that I am qualified to advise you on this decision. I just like the opening to be as small as possible as a babe. As to longevity - I don't know any breeder, of any breed, however reputable, can make you that sort of promise.
As I said JMHO. :-) Hope that is of some help.
Jean