Momma cat has went crazy!

Hello everyone. I have 2 cats, a male and female. Unfortunately, I thought the male was too young to breed, and it happened. Well, the kittens are now 5 weeks old, and doing well. They are healthy and loveable. Momma is who I am worried about. She is healthy, but she has gotten extremely aggressive, and started attacking my dogs, and my roommate. At first, I assumed she was being protective of her babies. Until she started attacking them. She isn't AS aggressive with them, but she does smack them around. And I haven't quite figured out what is provoking. She will be up on my hutch, just napping...and all of a sudden wake up, run across the room, and attack one of the dogs..doesn't matter which one, she has attacked all 3. Before, she LOVED my dogs. She cuddled with them, and would even clean them. The last couple of days, she has even started urinating during these attacks. Is there such a thing as postpartum depression for cats? Now that the kittens are old enough, I want to have her spayed, but I'm afraid she will really go nuts at the vet's office, and end up really hurting someone or herself. Is there anything I can do to help her calm down? I would understand more if the dogs were threatening her or the babies, but usually they aren't even near the babies when she attacks. The last one(about 5 minutes ago) she attacked my beagle, and he was asleep right in front of me...at least 10 feet away from her, and 15 feet away from the kittens! Any advice is greatly appreciated!