How many times a year can a dog get pregnant?

Answer 1

If it's already pregnant, it can't get any pregnant-er. You have to wait until after delivery, and then some.

It's possible, but considered unhealthy, for a dog to have two litters in one year.

Answer 2

Depending on the dog, it's usually twice or thrice a year.
You should ONLY breed a female 1-2 times a year, and a male can stud up to three times a week for best results.