On various occasions, pet owners sometimes find themselves with owning a pregnant rat. This may be the scenario where the rat was purchased from a pet store and nobody knew or it may be that the rat has come through a rescue organization, and the person that is running the rescue or the sanctuary was unaware as well. In these instances where the rat is pregnant, a lot of times the female is very well-equipped at handling the pregnancy, delivering the pups, and not having any major complications with raising them and rearing them.
It does indicate that, if and when she's pregnant, there are going to be a lot more rats, as they can have litters anywhere from two or three, even up to seven to nine pups at a time. The female rat may need some additional nutrients during the time that she is reaching the end term of her pregnancy. She may require a little bit extra calories and a little bit of extra nutrition during the time that she is lactating and feeding those babies.
In most cases, rats are very adept at dealing with their pregnancy, delivering the pups, and taking good care of them. As long as they're not in a stressful environment, they're not overcrowded, they often will raise and rear those young pretty effectively. The situation sometimes does arrive where there's an accidental pregnancy. Somebody has a young male and a young female rat and they were planning to have them spade or neutered and just hadn't done it yet.
In those cases and with an accidental pregnancy, it may be a choice if we know that it's happened to still perform an ovary-hysterectomy on that female early in term. If it happens to be late in term, it's best to let her deliver the pups. Hopefully, with the ability to either keep some or re-home them. So dealing with a pregnant rat, hopefully is a scenario that we don't run into as we do more spaying of rats, but should it happen the best case scenario is that the female will not have any complications, will deliver healthy rats, and those rats can then be re-homed.