Spay before first heat/pediatric spay is an American thing - 'heats' are a natural part of life, if you're confident in your ability to manage, then I'd wait.
Surgical neutering dramatically alters the biochemical profile, we condone it for our convenience & stress the health benefits while downplaying the negative effects, instead of educating pet owners on responsible pet management.
North American vets push early spay/neuter - I have friends who loved their vet clinic but were informed that if they didn't alter their dog by 6months, they were no longer welcome as clients
Another friend purchased a lab from a breeder who included in the contract that the dog would not be spayed until 11-12 months, at every puppy appointment, the clinic continued to push spay (are we spaying her today
- even though she was booked for vaccines - let's book her in for a spay next week
etc) despite the fact that the owner had clearly stated that his dog would not be spayed prior to 11 months as per their contract!
As with any surgical procedure there is an element of risk, most pets come through alters just fine, a few do not - when it's your dog/cat in the few
, the numbers seem alot more significant.
So don't let anyone make this decision for you or push you in one direction or the other - she <u>your</u> Sam, <u>you</u> get to decide.