Q. My dog has dropped 10 pounds in a month. Was consistently gaining 5 pounds in previous months. I wormed him to see if he had worms. None detected. He
A. Ten pounds in a month is a significant weight loss, even for a large breed like yours. This may be due to a number of organ diseases (such as inflammatory bowel disease), viral or fungal infections, or tumor, to name a few possibilities. He needs to be evaluated by the vet, who will probably do lab work and other diagnostics (x-ray or scan)), for a definitive diagnosis and treatment plan.