I do dog sitting, and I bring a few dogs back to my house, otherwise I go to their house. I have a little beagle, and she took to a little puppy I brought home to watch. They got along the best I have seem 2 dogs get along. They played and wrestled from morning till night. Well the puppy went back home the other day, and now I think my dog is in depression. She eats, but she does not want to do any of her normal things she does daily. She does not even want to go for walks. We can't really think about getting another dog right now, cause we are in the process of moving. Will she be ok, and are there any suggessions on how to get her out of her depression.
We are sorry to hear about the situation with your dog. It does seem that she enjoyed having that wee puppy around. Has she littered before? It could be her motherly instincts taking over. Have you tried socializing her with other dogs and using this as a bribe to get her to go on walks? How long has it been since the puppy left? If it has just been a few days I wouldn't worry too much about it. She will probably be back to her normal self soon. If it has been longer than a week I suggest that you use new toys, food or other dogs in your neighbourhood as bribes to get her to be active again.
Another aspect to consider is illness. How old is your pooch? Could she be lethargic because she is ill? Is she eating and drinking normally? Keep an extra eye out for subtle changes in her behaviour and take her in to see a veterinarian if you have any suspicions. Dogs are stoic animals and they hide illness pretty well. Keep watch on her urination and defecation habits too as these can be clues to determining what is wrong with her.
I hope this helps! All the best, I hope she recovers soon.