My jack russell terrier is 5 months old. She was acting fine up until we left her for 3 days to go visit my brother in college. Ever since we got back her private has gotten really swollen. we think she is on her heat cycle. EVer since we got back she has been very mean. Everytime someone tries to pet her she attacks and growls and bites you til no end. She is very vicious and we really don not want to get rid of her. She even attacks when we pick her up or even pet her. I have never seen anything like it! Is it because of her cycle, or is this something that will not go away over time. This is all out of the blue she has never acted this vicious before she even made us bleed!