Diarrhea is a frequent cause of visits to the Animal Clinic at Thorndale. Fortunately, many diarrhea cases respond quickly to symptomatic care. A small amount of red blood streaking the outside of the stool is generally not a cause for alarm. That is likely due to the breakdown of some small vessels near the anus secondary to the straining to defecate. However, when the diarrhea and/or vomit appear to be mostly composed of blood, your need to call our doctors at the Animal Clinic at Thorndale right away. Hemorrhagic gastroenteritis, or HGE for short, can be a rapidly debilitating, and potentially fatal disorder. Fortunately, when diagnosed and treated rapidly with intravenous fluid therapy, most of the dogs with HGE make a very rapid recovery.
Hemorrhagic gastroenteritis (HGE) is a fairly common disorder of dogs that is characterized by the sudden development of vomiting and/or diarrhea. The vomitus and the diarrhea may contain variable amounts of bright, red blood or dark, digested blood.
Contributing Factors
There are no known contributing factors. Most dogs appear healthy prior to the onset of clinical signs.
Prevalence
Any breed may be affected but certain breeds are more often involved. Usually, the dog is a young to middle-aged small breed, such as the miniature Poodle, miniature Schnauzer, Dachshund, and Yorkshire terrier.
Causes/Transmission
The exact cause of HGE remains unknown.
Clinical Signs
There is some variability in both the severity and course of this disease but, generally, signs are very sudden in onset. Vomiting is followed by the onset of bloody diarrhea. The rapid onset of profound dehydration is one of the hallmarks of HGE. The continuing loss of bodily fluids can progress so rapidly that hypotension (low blood pressure) and may shock develop. Fever is not a characteristic finding.
Diagnosis
The diagnosis of HGE is one of exclusion, meaning other possible causes of bloody vomitus 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 cost of all these tests could be significant, it is sometimes prudent to treat the dog for a short while with supportive care to see if the signs resolve. More details on this are given below.
The blood count of affected dogs is characterized by an extremely high hematocrit (red blood cell count). Most normal dogs have a hematocrit of 35-55%, while dogs with HGE may have hematocrits well above 60%. The elevated hematocrit provides the veterinarian with an important diagnostic clue that the dog may have HGE.
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 therapy given at the veterinary hospital provides the cornerstone of therapy for HGE. Fluids given under the skin (subcutaneous fluids) are generally 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. Eventually, the blood may become so thick that it flows very slowly through the blood vessels. In this situation, the dog is at risk for a potentially fatal clotting disorder called DIC. Once DIC has begun, it is often irreversible and often leads to death of the animal.
Additional therapy may include antibiotics and anti-ulcer medication.
Prognosis
The prognosis is usually good for complete recovery. The key is to catch the dog before it is severely dehydrated and treat with appropriate volumes of intravenous fluids. A small number of dogs will have a later recurrence of the disorder.
Transmission to Humans
Canine HGE poses no known health risk to humans.
Prevention
Because the cause is unknown, there is no recommended preventive therapy.