3- Lack of energy .
Has there been any significant changes in your dog’s energy level ? Lethargy is also one of the
common signs of cancer in dogs , no one knows your dog’s normal behavior better than you , so even
you veterinarian may not Always catch .
If you notice that your dog is spending less time playing , sleeping a lot , or becoming uninterested in
his usual activities , so begin looking for other signs your dog has cancer .