Today's post was written by Dr. Jennifer Ratigan, a veterinarian in Waynesboro, VA. I’ve known Jen since before we attended veterinary school together and thought you might like to get her take on the world of veterinary medicine. She’ll be contributing posts to Fully Vetted from time to time.

I have had several friends and family members call me in the evening, or on a weekend, very concerned because their dog has “blood pouring from his rear end.” When I ask a few follow-up questions, it becomes clear that what is really happening is the dog is having frequent episodes of bloody diarrhea.

To most people, this can be very scary. The dog is very uncomfortable and may be depositing this mess in the house or, at the very least, going outside every few minutes and looking pretty miserable. He may also be vomiting and is likely not eating.

This condition is called Hemorrhagic Gastroenteritis (HGE). It literally means bleeding and inflammation in the digestive tract. The cause is not known, but risk factors include stress and hyperactivity, and it is seen more often in smaller breeds of dogs. The bloody stool is often referred to as looking like “raspberry jam.” The dog can become dehydrated and debilitated very quickly, making this a potentially serious medical condition.

Diagnosing HGE is fairly straight-forward. The description of the stool and acute presentation, along with a simple blood test, called a packed cell volume (PCV), is indicative of this disease. A PCV is the measurement of the number of red blood cells in a volume of blood. The test can be performed with just a few drops of blood. Dogs with HGE usually have a PCV of over 60 percent because they have lost a lot of the fluid component of the blood into the intestinal tract.

The stool is often examined microscopically for the presence of bacteria called Clostridium. Research has failed to definitively prove Clostridium causes HGE, but it is thought to be associated with the condition. Dogs are usually placed on antibiotics to treat for these bacteria. Parasites such as hookworms and Giardia may also cause bloody stool, so it is important to look for these organisms to make the correct diagnosis and prescribe the appropriate treatment.

Treatment usually consists of aggressive hydration with intravenous fluids (IV), anti-vomiting and nausea medications, and antibiotics. Several days of hospitalization are often required for treatment. The good news is that the most dogs will recover uneventfully and return to normal in a few days or so.

Until we know the cause of this condition, we won’t know the best way to treat it. Many veterinarians feel that antibiotics may not be needed and should be reserved for more serious cases (especially those animals with low levels of infection-fighting cells i.e., those who are “neutropenic”) to prevent antibiotic resistance. There also has been recent discussion about the effectiveness of oral electrolyte solutions, for both people and animals with mild diarrhea. However, due to the severity of dehydration in HGE, this is not likely to be an effective treatment for these dogs.

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