My rat terrier behavior has cahnged

Question
She is usaually very energetic and lively . Now she seems skittish and will roll over on her back she seems afraid and or depressed. I have 6 dogs and nothing has changed in the household or the pack. She still has an appetite not dooms her business in the house just seems very sad and scared. I can not figure it out. Thanks

Answer
Any time a dog exhibits a sudden change in behavior, it's best to have your veterinarian examine her for any problems that might not be obvious to you.  Something has changed, even if you don't know what it is yet.  It might be worthwhile, if the vet clears her as healthy, to have a behavior professional come to your house to observe.  You can find one at the IAABC web page.