How much should a female 5 year old shih tzu weigh?

My dog named Patches we believe is pregnant. If she is 4 pounds over the weight of a normal dog she is most likely pregnant. She is digging, vomiting, shivering, and doing every other sign that a dog does when they are pregnant. She is due any day now. Please answer!!!

9-16The standard for a shih tzu weighs 9-16 pounds. But with those conditions I strongly recommend taking her to get checked by the vet. Good luck!

A shih tzu can weigh anywhere from 9-16 lbs. It definetly sounds like your dog is pregnant, and if digging and shaking, she could be in labor. Get your dog to a vet now. If she mated with a larger dog, she might not be physically able to pass the puppies. Even when mated with the same breed, small dogs often need a c-section. Small dogs can die because the puppies are too big to come out. Try to get her to a vet ASAP and even if she's not in labor, you can schedule a c-section. Either way, best option is the vet. Now.