Bleeding when a dog sneezes may be caused by irritation of the nasal cavity leading to capillary rupture. It may also be caused by trauma to the nasal cavity and turbinates or problems with coagulation function. If the nose is dry and accompanied by symptoms such as nasal discharge and nosebleeds, it may be a nasal disease or infectious disease. There are many reasons why dogs sneeze and bleed. It is best to go to the hospital for examination and treatment. A normal and healthy dog's nose is moist except when sleeping. If the nose is dry and bleeding, timely examination and treatment are required.