> How many litters do you feel is OK for a bitch to have in her lifetime
Depends on the bitch and her lifetime.
One who has one litter and has problems, poor puppies or comes through the whole process badly then one's enough.
Another shells them like peas, produces better than herself,comes out the other side of the litter looking a million dollars then 2 or 3 litters could be considered taking into consideration the state of the breed as a whole.
Having a 4th litter from her would be greed - unless your whole kennel had been wiped out or this bitch was found to be the only clear dog in a restricted gene pool with genetic problems. IMHO