my bitch is 53 days (if i count day of mating day one, dont know if you do?) and she is breathing heavy/fast most of the time, is this normal? some of it could be due to the heat but it has cooled down in the house now and she is still doing it.

at what day of pregnancy are the pups viable from?

hi ,even tho its cooled down alittle she will still be very hot and big everthing is all squashed together ,when the pups move down she will be able to breath alot better ,pups are viable from day 58 ,good luck

I've had a litter born on day 57 ( only one mating ) and they were fine , although we did lose two out of six. This was due to other complications though.
Good luck with your pups when they arrive.
My bitch who went early last time is due on June 7th but I'll be expecting her to go early this time instead of a mad panic.