Isla my sheltie had her first season on 24 June, therefore I assumed that she would have another around 24 December (nice!).

Isla is the first unneutered bitch I have had so I don't know much about seasons yet!  I noticed this morning that she was rubbing herself rather suggestively up against one of my other dogs (a female!).  This is unusual behaviour for her and I have only seen her do it at the start of her season last time.  Could this mean that she is about to have another one, not even four months after the first?  I have been told that generally seasons are 6 months apart but does this vary?

Help please!

Snowflake

Until she's had two or three seasons you won't know her individual cycle - it could be anything from four months to 12 months, and anything in between! Six months is the average, just as 28 days is the average cycle for women - but most (bitches and women!) vary from the average.