Good morning, I have a 10 month old girl who is coming into season (this will be her first), can they have a season without any blood?  I have never had a female dog before, her nipples have got large, this is quite hard to describe, please bare with me.  She is a Cane Corso x Old Thyme Bulldog, she is very much a Cane Corso so she has quite a large expanse between her bum and her vulva this bit is swollen but her vulva is only slightly swollen.

Some can have what is known as silent seasons but from what you describe she isn't yet in season but is on the verge. Keep your eye on her daily from now on to notice the day blood starts then she will be in season for at least 3 weeks(it can be longer), so keep her well away from males, particularly entire ones for all this time.

Thank you

At this point I would wipe her vulva with a tissue each morning to pinpoint the first day, then keep her on lead and away from male dogs for 28 days as some bitches have longer seasons and ovulate late.