"Dog vomiting blood or Hematemesis (blood in vomit) refers to the presence of streaks or clots of blood in vomit. A dog throwing up blood may be suffering from a life threatening condition, or it may be due to a nominal secondary cause. Bleeding disorders, hemorrhagic (excessive discharge of blood from the blood vessels) gastroenteritis ( stomach and intestines problems), tumors, inflammation of the stomach and esophagus, drugs, surgical wounds, ulcers, poisoning or shock may leave a canine vomiting blood. Blood in vomit may be the only sign or some other general signs may be present, such as bloody diarrhea, anorexia, weakness, thirst, abdominal pain and progressive weakness, can be associated with this condition. In any case, severe or mild, detailed clinical and laboratory diagnosis is essential to sort out underlying causes; as it can eventually become a life threatening symptom. Treatment plans depend upon the underlying causes and symptoms shown by the affected dog."
Dogs may vomit due to a complex mechanism, controlled by a specialized center in the hind brain. Different factors can trigger a nervous response in the brain which result in nausea, followed by vomiting. Dogs may vomit out all or some stomach content, but sometimes it happens so that blood& is also included in the vomit; which appears as either fresh and bright or brown in color, Dog vomit color helps in making a diagnosis.
A dog vomitng blood may be due to a severe stomach or esophagus disorder. Hemorrhagic gastroenteritis is considered the most common cause; which is caused by a number of triggers, but only those that are considered important can cause vomiting as a symptom. In the case of gastroenteritis, other signs, such as anorexia (loss of appetite) and bloody diarrhea are more common.
Bleeding disorders, like coagulative (becomes less like a liquid) deficiency can be another cause, due to which blood continuously escapes into the gastrointestinal tract. Vomiting is frequent in such cases; escaped blood proteins initiate the mechanism of this type of vomiting.
Tumors and obstructions can cause severe damage to the epithelium (lining) of the stomach and esophagus, that leaves dogs vomiting fresh and bright blood. Esophageal and stomach tumors, especially malignant (threatening to life such as cancer or neoplasms) tumors cause expanded damage, while benign (slow growing not cancerous) tumors which are rare, but can cause obstruction in the passage, thus exerting pressure on and resulting in bruising of the epithelium. Vomiting is a common sign in cases of esophageal and stomach tumors, thus blood passes with the vomit.
Some anti-inflammatory drugs and corticosteroids, if used for a prolonged time or in high doses, may cause severe damage to the lining of the gastrointestinal tract. These lesions then develop into ulcers; which continuously bleed. Blood is then passed with vomiting.
In some diseases of the kidney, spleen, liver or pancreas, blood may pass into the gastrointestinal tract; which is then mixed with digestive content and results in a dog vomiting blood.
Poisoning, internal injuries and surgical wounds, may be some other causes for vomiting blood.
Some mild or nominal forms of blood in vomit may occur in dogs, due to food intolerance, ingested dental pieces such as teeth, skin licked or nasal blood; can be ejected in a single rapid course of vomiting.
Clinically a dog throwing up blood may be the only sign, as in mild cases, but some other signs, such as anorexia, diarrhea, bloody diarrhea, lethargy, loss of condition, weakness, repeated blood vomit, abdominal pain, nausea etc, might also accompany this symptom, representing severe underlying causes; which may turn into a life-threatening emergency.
Signs of shock may include the vomiting of blood, which is the most serious problem associated with a dogs vomiting blood. It should be immediately responded to on an emergency basis.
Clinical examination of the dog for accompanying signs and detailed examination of the vomit contents is required. The appearance, frequency, physical consistency of the ejected contents, nutritional, medical and recent disease history should also be noted.
Food intolerance should be noted at the time of feeding. Dog
just after or during feeding; should be suspected for nutritional
intolerance. In this case food ingredients should be monitored to see
if any one is a trigger or cause of this condition.
Laboratory procedures should be conducted in detail. Coagulation profiling and blood biochemistry procedures should be conducted to confirm or reject the possibility of blood disorders. Urinalysis for kidney disease, radiography, biopsy and endoscopy for tumors, obstruction, fecal and blood examinations for toxins, parasites and infective agents, may be required.
Clinical signs should be treated as they appear; meaning symptomatic treatment should be initiated during the diagnostic procedure. Fluids, blood transfusion or supplements; as required should be supplied, depending upon the condition of the affected dog.
Dogs must be kept on “No per Oral” (no food through the mouth) approach to minimize vomiting, dogs should be supplied nutritional components intravenously; these may include calories, proteins and vitamin complex.
Drugs for controlling vomiting; should be selected with care, some drugs, such as Omeprazole, Famatodine etc, are preferred in place of conventional anti–emetic drugs (drugs that stop a dog from throwing up). Similarly, anti-inflammatory drugs should be strictly prohibited.
Once the underlying cause is confirmed, it should be treated, as per the advice of a veterinarian. Anti-biotics may be required for infections. Similarly, prostaglandin drugs can help in overcoming ulcers.
Surgical options to control bleeding, to remove obstruction and to remove tumors becomes essential in advanced and severe cases.
The Merck Veterinary Manual
J. K. Dhun, Textbook of Small Animal Medicine (Elsevier Health Sciences, 1999)
McGavin MD, et all. JF Thomson's Special Veterinary Pathology (St. Louis, Mosby .2001) Revised Edition.