There are many reasons why your dog may suddenly look more tired than usual. If it parties or eats less than before, you need to visit your veterinarian! He or she will take a look at it and will indicate if you need to do blood tests. If everything is normal and that your dog is reaching an advanced age (around 10 years old for small races and 7 to 8 years old for big races), this loss of energy may be attributable to age. It is getting older just like everyone else! You can help it recover its form using food supplements that will stimulate its metabolism. It may also be that your dog’s age means it has older joints. In that case, it will play less, struggle to get out of its basket… Find here more information on mobility disorders.
It is unfortunately sometimes the case that your veterinarian will have bad news for you. Your dog may be suffering from a chronical illness, a cancer, or may have to undergo a significant surgery. To help it recover from surgery you can stimulate its metabolism and appetite by giving it a food supplements on top of the treatment prescribed by your veterinarian.