Faithful. Book 1. When all people disappeared

Every year, the golden labrador Max spent several days in a veterinary clinic. It was unpleasant, but tolerant, given that the owners always returned, and Max always liked new acquaintances. This time, his neighbor was an elderly black labradorsh named Madame Curie, a dog with great life experience and a wonderful sense of humor. Time after conversation with her flowed unnoticed, but suddenly the day came when Max was left alone. No one came to pick him up from the clinic. No one brought food. All neighboring cells are empty. In this nightmare, Max lived for another week and, perhaps, would just have died locked up if it had not been for the dachshunds named Koropysh. His owners also disappeared somewhere. All people disappeared in general.
Max, Korpysh and the cheerful Yorko Yorko, joined in their company, go in search. They go through depopulated lands and abandoned cities in which abandoned animals are trying to survive. Max desperately wants to find his family and is sure that Madame Curie could help him in this - her words, spoken on the eve of the disappearance, do not come out of his head. The wise Labradorsha foresaw something bad and clearly knew something