My dog is inactive and very sad
If your she is apathetic and sad, this is a sign that something is not right. If your pet is more droopy than normal, this may be because she misses someone or because she hasn't gotten used to new routines. Give it a little time and if the condition does not improve in a couple of days, take your pet to an ethologist (a veterinarian who specializes in animal behavior).
If the sadness is accompanied by other symptoms such as diarrhea or vomiting, disorientation, panting, drooling ... Urgently go to the veterinary clinic, as these are serious symptoms.
All the best,