Teddy's lack of energy may be caused by food deterioration, gastrointestinal problems, internal parasites, malnutrition, canine distemper, parvovirus, etc. You need to observe whether the dog has other symptoms. If the dog vomits , diarrhea, blood in the stool, etc., it is best to send the dog to the pet hospital for examination and treatment immediately; if the dog has no other conditions, you can feed the dog some probiotics to regulate the intestinal tract, and you can also improve the dog's diet.