Dr. Danielle Wassink, an emergency-care vet at Animal Critical Care and Emergency Services (ACCES) in Seattle, answers the second of a two-part series on bloody diarrhea in dogs.

Question: What is hemorrhagic gastroenteritis?

Answer: Hemorrhagic gastroenteritis, known as HGE, is characterized by an acute onset of severe bloody diarrhea, with or without vomiting, in an otherwise healthy dog.

HGE often starts acutely, without warning, in a dog that was acting normally several hours prior. Other times it may develop after a day or so of diarrhea, lethargy or vomiting.

The diarrhea is very alarming as it is typically described as looking like "raspberry jam" or watery blood. There is not often any typical brown diarrhea present.

Though most often described in small breeds of dogs, any breed, gender and age of dog can be affected.

While the causes for diarrhea with blood are numerous, HGE is one of the more common reasons we see dogs at the emergency room for bloody diarrhea.

Question: What causes HGE?

Answer: The underlying cause of HGE is unclear, though inciting factors can include overgrowth of certain bacteria (Clostridium perferingens), food allergies, bacterial toxins, eating of trash and stress. Some pets have a history of getting into the trash or a bounty of table scraps, especially around the holidays. However, most animals with HGE do not have any significant previous history to point to an underlying cause.

In general HGE is not considered to be contagious; however, sometimes multiple dogs from a household are affected. In these cases, there is typically an inciting factor affecting both pets, such as stress related to moving or both dogs getting into the trash.

Question: What are the clinical signs of HGE?

Answer: Owners often describe the diarrhea as "raspberry jam" in color and consistency that often starts acutely. Some dogs may have a few episodes of diarrhea before it becomes bloody. Vomiting is also common, and occasionally there is blood in the vomit as well.

Depending on the severity of illness, some dogs are not eating, and they can become very lethargic or weak. Even if a dog is eating some or drinking water, he or she often cannot keep up with the amount of fluid being lost and dehydrates quickly.

Catching and treating HGE as soon as possible is very important because severe dehydration can lead to low blood pressure and shock.

Question: How is HGE diagnosed?

Answer: Diagnosis of HGE is based primarily on history, exam findings, blood work and collection of a fecal sample.

A simple blood test, packed cell volume and total protein (PCV/TP) is performed when HGE is suspected. This test allows the veterinarian to get an understanding of how dehydrated the pet is and how much protein they have lost in the diarrhea.
Full blood work can also help determine if there are any underlying metabolic or organ problems.

A fecal sample is used to look for bacterial overgrowth, as well as rule out parasites that can cause similar symptoms. In young dogs (under a year old) or puppies, testing for parvovirus is typically recommended, regardless of whether they've been vaccinated.

In some cases, X-rays may be warranted in dogs that are vomiting to rule out a foreign body or blockage.

Ultrasound can also be done to more closely evaluate the internal organs and intestines in animals that are not responding to care as expected.

Question: When do I need to take my dog to the vet?

Answer: Dogs with HGE can get worse rapidly and may need to be seen by a veterinarian immediately. If it is late at night and you are unsure how quickly your pet needs to be seen, contact your veterinarian or an emergency clinic after hours for advice.

Question: How is HGE treated?

Answer: Some type of fluid treatment, antibiotics and gastrointestinal protectant drugs (such as antacids) are commonly used.

More specific treatment depends on how ill and dehydrated your pet has become. Most dogs with HGE require hospitalization; however, very stable dogs that are alert, active, not vomiting and not overly dehydrated may be treated by your veterinarian as an outpatient. They may receive fluids under the skin (subcutaneous fluids), injections for nausea and sent home on oral medications, and a bland diet may be recommended.

The majority of dogs with HGE are very dehydrated and more aggressive care is needed. These pets are hospitalized and placed on intravenous (IV) fluids and IV medications.

We commonly treat HGE in the emergency setting and most dogs improve and are ready for discharge 24 to 48 hours after being admitted to the hospital. These patients are then continued on oral medications at home.

Some animals can become critically ill, either from severe dehydration or sepsis (systemic toxemia) that leads to shock. These animals require emergency stabilization, critical care and are hospitalized for several days with more extensive treatment.

Question: What is the prognosis if my dog has HGE?

Answer: Typically the prognosis for HGE is excellent with early treatment. Prognosis becomes more guarded in animals that go into shock or in dogs that develop sepsis. The best way to ensure a good prognosis is with prompt treatment when bloody diarrhea begins.

Dr. Danielle Wassink

Wassink graduated from Washington State University's College of Veterinary Medicine in 2004 and completed an internship at the Animal Medical Center in New York in 2005. She has a special interest in trauma and pain management. She lives with a pit bull mix.