Diagnosis
The diagnosis of HGE is one of exclusion, meaning other possible causes of bloody vomiting and/or bloody diarrhea must first be considered. Some of these possible causes include ulcers, trauma, gastrointestinal tumors or obstruction, foreign bodies, infectious diseases, and coagulation disorders. Evaluation of these other causes might require such tests as a complete blood count, biochemical analysis of the blood, urinalysis, x-rays, coagulation tests, fecal evaluation ultrasound or endoscopic (fiberoptic) evaluation of the gastrointestinal tract. Because the costs of all these tests could be significant, it is sometimes prudent to treat the dog for a few days with supportive care to see if the signs resolve.
HGE is most common in small breeds of dogs. The blood count of affected dogs is frequently characterized by an elevated hematocrit (red blood cell count). Most normal dogs have hematocrits of 37-55%, while dogs with HGE may have hematocrits well above 60%. The elevated hematocrit provides the veterinarian with an important clue that the dog may have HGE.
Causes
The cause is uncertain. Suspected causes include abnormal responses to bacteria or bacterial endotoxin, or a hypersensitivity to food. Pathologically there is an increase in the permeability of the intestinal lining and a leakage of blood and proteins into the bowel. Clostridium perfringens has been found in large numbers in the intestines of many affected dogs.
HGE occurs in all breeds of dogs, at any age. However, it appears to occur more frequently in small and toy breeds of dogs. Breeds that seem to have a higher than average incidence of hemorrhagic gastroenteritis are the Miniature Schnauzer, Dachshund, Yorkshire Terrier, and Miniature Poodle. The average age at onset of disease is 2-4 years old, and there is no gender predisposition.
Treatment
Dogs with HGE will appear profoundly ill and, if left untreated, may die. In most cases, the disorder appears to run its course in a few days if the animal is given appropriate supportive care. Intravenous fluid therapy provides the cornerstone of therapy for HGE. Fluids given under the skin are not considered adequate to meet the significant fluid requirements of most dogs with HGE.
If intravenous fluid therapy is not given, the dog's red blood count will continue to elevate due to dehydration. Eventually, the blood may become so thick that it flows very slowly through the blood vessels. In this situation, the dog is a prime candidate for a potentially fatal clotting disorder called disseminated intravascular coagulation (DIC). Once DIC has begun, it is often irreversible and may result in death.
Additional therapy may include antibiotics and anti-ulcer medication. With prompt, aggressive treatment, the prognosis is good. There is less than 10 percent mortality with treatment, but 10 to 15 percent of cases will recur.
Prognosis
Hemorrhagic gastroenteritis typically lasts about 2-3 days. The majority of dogs recover with no complications if they are treated early on in the disease. Dogs that are not treated have a poor prognosis for recovery. Pet owners should always be aware that a small percentage of dogs with HGE will suffer relapses.
Since the cause of hemorrhagic gastroenteritis is still unknown, there is no way to prevent the disease. Thus, it is important for owners to act quickly when their pets show signs of illness.
