My mother has a chihuahua about 4 years old. Twice now, she thought she may have had a seizure, but isn't sure. The first time, her Chi was shaking uncontrollably while sleeping as if she was having a running dream. Her eyes appeared normal and no other signs of a seizure. Now, last night, which has been about a month since the last episode, she was sleeping and all of a sudden she started shaking her head back and forth and spit was flying out of her mouth. She said it was "frothy". She picked her up and said her jaw was clenched. She wiped her mouth off and her Chi woke up and was fine. She said her eyes were normal, they weren't going back and forth or anything. Is her Chi seizing?? Please help, any advice would be greatly appreciated.