A sudden case of bloody diarrhea is often the first sign that a dog may have hemorrhagic gastroenteritis (HGE), which causes gastrointestinal bleeding. The disease may also cause vomiting along with other symptoms and it often comes on very quickly.
If you notice blood in your dog's stool, it is important to contact your veterinarian right away. While this is also a symptom of many different illnesses, it is serious and needs to be treated aggressively. If left untreated, HGE can be fatal. However, with prompt veterinary care, most dogs respond to treatment and recover in a few days.
Signs and Symptoms
The most notable sign seen with HGE is a very sudden onset of bloody diarrhea in a previously healthy dog. It is often a bright red and many people compare it to raspberry jam. You may also notice a foul odor that is anything but normal.
Other common symptoms include vomiting, loss of appetite (anorexia), and a rapid decrease in energy (listlessness or lethargy). Dehydration is usually not seen clinically on initial presentation, but shock can develop quickly without treatment. Likewise, some dogs may develop a fever, though this is not very common.
Because there are many causes of vomiting and diarrhea in dogs, it is always recommended that you call your veterinarian to discuss what is going on. Only your vet can properly advise you if it is a situation that can wait or if it sounds like an emergency.
The exact cause of this disease is unknown, though there are a number of theories. These include an adverse reaction to a change in food, a bacterial infection or a virus, or a reaction to intestinal parasites. Additionally, it's thought that stress or a hyper disposition can play a role in the development of HGE.
Dogs that have an episode of HGE may be prone to another occurrence. Many dogs never experience HGE.
HGE can affect any breed of dog at any age and it is not more prevalent in males or females. The initial case may occur around 2 to 5 years of age.
There does tend to be a higher percentage of cases in toy and miniature breeds. In particular, Yorkshire terriers, Maltese, and miniature pinschers, schnauzers, and poodles are prone to develop HGE.
HGE is diagnosed primarily by ruling out other causes of a bloody stool. The sudden appearance of bloody diarrhea and a high packed cell volume (PCV) in a previously healthy dog rule in favor of the HGE diagnosis.
Other causes of gastrointestinal bleeding that must be considered as possibilities include gastrointestinal ulcers or cancer, colitis, parvovirus, and coronavirus. Your vet will also want to rule out bacteria such as Campylobacter sp, Salmonella sp, and Clostridium sp, and Escherichia coli.
It is likely that your vet will also check for other health issues such as:
Treatment and Recovery
If your dog is diagnosed with HGE, it is likely that hospitalization for several days will be necessary. That is because aggressive supportive care is required during treatment and it is not something that can be done at home.
It's typical for dogs to receive no food or water by mouth for one to four days. Instead, they will receive intravenous (IV) fluid therapy with potassium added to the fluids. Antibiotics are also recommended, delivered either through IV or subcutaneous injection.
Food should be reintroduced slowly. In the event that the HGE is thought to be food related, your vet may also recommend switching to a novel protein (such as chicken, lamb, or cottage cheese) that the dog doesn't usually eat.
The good news is that with this aggressive care, most dogs recover within a few days. Some dogs can have repeated episodes of HGE. After your dog's recovery, ask your vet for any recommendations of ways you might be able to reduce the risk of reoccurrence. For example, feeding your dog the same high-quality food rather than switching it periodically may help.
Mitchell KD. Hemorrhagic Gastroenteritis in Small Animals. Merck Veterinary Manual. 2018.