Hi!
I'm new. :-)
I have a 3 1/2 month old BC/Mcnabb cross (3/4 border collie) who looks like he's going to be a really BIG dog. He's 26 pounds and growing so fast I swear he gains a half inch in height every time I look away. He's really solid, too, with tons of bone -- he's going to be built like a tank when adult.
Age is correct. No adult teeth yet, and I've had him since he was two months and he was very obviously a (large) baby then.
Working lines. Both parents are working dogs from a ranch.
I have no reason to believe he's not as described as far as the breeding goes -- he moves, acts, and looks like a smooth coated border collie, albeit one with floppy ears and a big nose. When he's got his eye on something, he's all border collie, even this young. He's also incredibly smart in almost spooky ways. (And I've had several stock dogs, including a BC/aussie and an aussie/heeler mix.) Willing and eager to please. Should be a good dog.
He's bilateral cryptorchid. I expect I'll be paying for a "spay" rather than a "neuter" and had planned to do it in the fall, for reasons. I've noticed some unusually early boy-behavior (marking where other dogs have gone, mostly) which I expect is due to WAY TOO MUCH testosterone due to being cryptorchid.
Could an excess of testosterone be causing his large size? Anyone know any studies on this or hard data?
I'm tempted to neuter him super early anyway (maybe even before fall, rather, in the next few months), because of the cancer risk and his behavior.
On the other hand, if the cause of his growth rate is NOT excess testosterone, I know neutering him early may encourage even more growth than he would have because neutered males get taller than intact ones, right? From a performance aspect, I'm worried about him growing too big.
(Normally, I like to leave dogs intact until they're completely done growing and the growth plates are closed, but meh, it's six of one, half dozen of another on this guy.)