Mood Behavior

by Tom
(Derby)

Hi,my 8 year retriever started to eat grass on her walks. It seems to make her sick, and what was once occasional in now every time. She is on dry food and her appetite is good. There have been a few occasions when she brought bile up without grass. Then for no reason has not wanted to take her walks -- a complete change of behavior. She is not nasty. Any ideas? Thanks, Tom