
I'm not sure what age staffies normally first come into season, but generally speaking smaller breeds often start earlier than larger ones, and it can be 6 months. But if your bitch isn't coming into season, she could have a urinary infection or vaginal infection or similar as dogs often confuse ANy smell there for a season. In fact my boys thought a bitch of mine was in season when she had a wound on her eyelid as they smelled blood.
Marianne