According to petMD, the act of vomiting blood in dogs, also known as hematemisis, is caused by a variety of conditions that include irritation of the intestines and disruption of the esophagus. Dogs also vomit swallowed blood due to mouth injuries. Critically ill dogs have a higher risk of hematemisis.
VCA Animal Hospital explains that while most cases of vomiting in dogs resolve on their own within 24 hours, it is important for dog owners to consult with a veterinarian if the vomit contains blood in order to determine the underlying cause. Severe vomiting in dogs can signify liver failure, kidney failure or cancer.
According to Banfield Pet Hospital, if a dog is vomiting blood, it is important for its owner to consult with a veterinarian as soon as possible, as intestinal tract bleeding can be a life-threatening condition. Excessive blood loss can lead to complications with the internal organs, so time is of the essence. Causes for bloody vomit in dogs include trauma, ingestion of foreign bodies, clotting disorders, hemorrhagic gastroenteritis, stomach ulcers, hormonal imbalance, kidney disorders and liver disease. Dogs are treated based on the underlying cause of the vomiting. Treatments include intravenous fluids, anti-vomiting medications, de-worming and antibiotics.