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Hemorrhagic Gastroenteritis (HGE) A Common & Sometimes Life Threatening Disease In Dogs

HGE In Dogs

Here’s one disease that really freaks dog owners out. It can be mild, but some severe cases can be life-threatening, so it’s good to know what’s going on.

We’re talking about a syndrome called HGE: Hemorrhagic GastroEnteritis. Hemorrhagic means a big bloody mess. Gastro-Enteritis literally translates to inflammation of the stomach and intestines.  The primary symptom is a diarrhea that looks like straight blood. It’s bright red, sometimes gelatinous, which is why many veterinarians compare it to “raspberry jelly.”

Sorry to have ruined that food for you.

Owners often ask if the dog is bleeding internally. I can see why you’d think that, given the bloody mess coming out of your dog’s bum. But no, this is just some extremely unhappy intestines. It can often seem out of the blue, and many times we never do figure out what got this whole thing started. With many cases, the dog has been stressed (ie- people visiting, being boarded, moving, etc). Sometimes it can be from… oh, how to put this nicely… dietary indiscretion. Eating the gross dead thing in the yard, or getting into the trash.

Regardless of the why, you’re now at the veterinary clinic, planning how to get the stains out of your carpet when you get home, and trying not to freak about this whole thing. Your veterinarian may glove up and extract a fresh stool sample from… the source. Once we see what we have, every vet knows exactly what this is. Then we start into our HGE speech:

This is a paradoxical disease. You’d think with all this blood coming out, your dog would be losing blood. Medically, we use the term “anemic” to describe an animal that has a low number of red blood cells. And your veterinarian will likely want to draw blood from your dog for testing, but we’re expecting the opposite. Turns out these dogs are never anemic.

Let’s talk red blood cells.  When we measure them, it’s usually given as a percentage of the blood, called a hematocrit (pronounced he-MAT-o-crit). For instance, most dogs’ blood (hematocrit) is around 40-50% red blood cells. The rest is the fluid (plasma) that the cells are floating in. HGE causes the dog to become incredibly dehydrated, more so than many other types of diarrhea. With dehydration, these dogs have less fluid for the red blood cells to float in. So while the number of red blood cells stays the same (which does seem weird given the fact these dogs are pooping blood), the amount of fluid decreases. This causes the percentage of red blood cells in the bloodstream (the hematocrit) to rise. (Conversely, if a dog were to have excess plasma, or fluid, the red blood cell percentage could fall, even though the number of cells is the same.)

So when we vets see what the poop looks like, the first thing we want to do is measure the hematocrit, expecting it to be high. This increase is the calling card of HGE. And good news – measuring a hematocrit is a simple test that is very inexpensive and only takes about ten minutes! Depending on age and breed, I’ll consider most dogs with a hematocrit over 55% to be diagnostic. That said, I have many really good owners who catch this early. The dog hasn’t had a chance to become super dehydrated, so they may have a hematocrit of 52%. I still call it HGE and treat it accordingly.

So, how is HGE treated? Well, we know that dehydration is the main problem, so we want to hydrate these animals promptly! For the dogs who are bouncing around the room and have a hematocrit in the low-mid 50% range, I’ll simply give fluids under their skin (sub-cutaneous fluids) and let their body slowly absorb those fluids after they go home. Dogs who are very lethargic, or have a hematocrit in the 60’s, and/or are vomiting are often hospitalized. These dogs need to be on IV fluids to rehydrate them. Either case, we’ll put the dog on antibiotics (oral pills sent home, or IV if in the hospital) that target the bacteria that are promoting the diarrhea. We’ll often feed a prescription diet that is easy to digest, to give the stomach and intestines a break.

Most dogs recover very well with treatment. The ones who are near collapse, and often with hematocrits well into the 60%’s, are the ones we worry about. Still, I had one severe case where the owners could not afford to hospitalize the dog. So we gave it fluids under the skin, and they brought the dog back every day for 3 treatments. Thankfully, the dog did great! Still, hospitalization of these super sick pets is the best – it increases their chances of recovery, as well as helps them feel better much sooner.

The good news – once your dog is better, you’re done! Most cases of HGE are not considered to be contagious, so usually the other dogs are not at risk. That said, remember there are a lot of potential causes, and often we never find the initial cause. If both your dogs ate the same gross thing in the yard, yes, they both could have HGE!

So if you ever see that unique style of diarrhea, get your dog the vet ASAP! Your veterinarian will be impressed when you know what HGE is, and you can ask what your dog’s hematocrit was.

Web-DVM guest blogger Dr. Karen Louis is a practicing small animal veterinarian.  See more of her articles at her blog at

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