Izi has started humping Betty today. She's not due in season until next month but she is a bit swollen and I think she had a split season last time. Do bitches who have one split season usually continue doing so? I've never had this before.

My bitch has had a split season but then the next time she had a normal one.  I spoke to the vet about it and he said it was quite a common occurrence but didn't necessarily mean it would happen every time.

Thanks for your reply. Maybe its a normal season, but its early if so. I don't want to breed her this time so its not a big deal. :)

i have 3 girls and 2 males in the house i have found about a month before the girls come in season they start to swell a little and start to hump each other then a couple of days later the boys become intresed for a day or 2 then it all settles down untill about a month later when they come in then again the girls seam to be the first to start the humping, In my house a month before a girl was due in i would say this is normal behaviour for my lot but as we all know no 2 girls are the same

Ah ok so maybe she's not abnormal after all ;)

4 months plus with an average of 6-7 month intervals is usual.  Less than 4 monthly intervals is linked to infertility and cystic ovaries. 

Less than four months doesn't give a chance for the body to go through the whole hormonal cycle.

GSD's are known for short inter season intervals in the same way as some breeds have long intervals.