Definition of lowâpressure. 1  1 : having, exerting, or operating under a relatively small pressure. 2  2 : easygoing.
Today some vets will spay/neuter at eight weeks of age, while other adhere to the old practice of six months of age. The average age at which pets are spayed or neutered is four months. Adolescent cats and dogs as young as five months can get pregnant.
A dog is pregnant for around 63 days. Milk is produced before whelping I can't say how far before but you will see her teats get inlarged. I don't know whether you meant to breed a 8 year old dog and if she is a purebred. But in my opinoin it is hard on a 8 year old dog.