hi,ive just had 1 of my whippets pts due to cancer,now ive only got 1 her sister who as been together all their llife.she was in kennel but ive moved her in the house now shes on her own.shes been find except when we go to work shes been barking and howling .any ideas how to stop this .ive thought about getting another freind for her ,but weather or not that will work or not.