Can someone possibly tell me how long will my 8mth old SBT bleed for, there has been some spots over a couple of days.  Will she bleed for 21 days?

No she won't bleed for 21 days BUT she will be in season for approx 21 days.A bitch is fertile AFTER the bleeding stops so please don't think you are safe to let her around males at this point.You are better keeping her away from males for 4 weeks after onset of bleeding just to be sure
Archer

My 10 month old Lab puppy has just had her first season and bled for 21 days to the point she was being taken to the vet but everything has settled down now.

Juast have to watch her for the next week or so.

Quite possibly, although some bitches do have a paler discharge in the second half of the season. In either case, you need to protect her from unwanted attention from males for the entire 21 days and a couple of extra days to be on the safe side.

It sounds like you would find the Book of the Bitch very interesting. It's available from Amazon for about £10.00.

Dawn R.