6 yr old female Frenchie. Was living in Oklahoma with 3 other dogs and human owner became sick was not in the home for quite a while. Became aggressive toward other dogs. Started chewing on nails and one became ingrown and had to be taken to the vet to be removed. Son came from San Diego and moved her to a home no dogs with 3 adults. She still chews her toe nails. Everytime she chews on her nails and we see her do it we tell her not to do chew. Sometimes we physically seperate her mouth from her foot. If anybody has any experience with this please respond or tell me what I can do to stop her from doing it.