
Ideal time to get spayed is midway between 1st and second season, but you must do what is right for you and your circumstances and your puppy.
I have never had a Boxer but do know of 3 that were spayed at 6 months old. One is now 11 years old and apart from routine jabs never needed a vet. The other two are now 7yrs and 8yrs old and never had any problems either.
I have had bitches of other varying breeds spayed at 6 months between first and second season and much older, also unspayed bitches. I have never had a problem with any of the spayed ones nor most of the unspayed except one unspayed bitch was incontinent and another had mammory tumours.
I do wonder if I had, had the incontinent one spayed would her incontinence been put down to the spaying. This then raises the question how many other bitches that get incontinent would have still done so had they not been spayed.
Because of the area I now live in since the death of my husband I did get my Rottie x GSD bitch spayed at 6months to avoid seasons with the amount of loose aggresive dogs round here. ok she is only 10 months now but is fit and healthy also