My niece tells me her vet said not to neuter her pit bull until they are at least a yr old because this will cause the animal to have a small head. I said bull-butter. Is this a myth or some weird scientific fact?

Myth.

The size of the dog depends on it's genetics, not it's testicles ;)

If the parents had a large head odds are the pup will inherit that trait as well.

Got to spread the love, Shaz. Well put.

I've always heard to wait until eight months before neutering to allow internal organs to mature, but the size of the head, no.

I Think the only thing that happens to dogs who get fixed ar an early age from what I've seen is they have a tendency to do a lot of humping beyond the age of where its needed and normal... a lot of pittie breeders breed for large heads and stout, solid bodies. Neutering him won't stop growth. A good age to neuter is around 8 - 10 months...