Hemorrhagic Gastroenteritis (HGE) in Dogs

Signs of HGE in Dogs

Signs come on suddenly in a dog that was fine hours before:^3,1

• Bloody diarrhea in large amounts, often red and jelly-like ("raspberry jam" or "strawberry jam").^1,10
• Vomiting, which often starts first.¹
• Lethargy and poor appetite, which can progress to collapse.³
• Belly pain, a fast heart rate and sometimes fever.³

Dogs lose fluid and protein into the gut so quickly that shock can develop before the classic signs of dehydration show.¹ See our dog poop chart and blood in dog stool for other kinds of bloody stool.

Which Dogs Get HGE?

Any dog can get AHDS, but small and toy breeds are affected most, especially Yorkshire Terriers, Miniature Schnauzers, Miniature Pinschers and Maltese. Miniature Poodles and Cavalier King Charles Spaniels are also listed.^1,3,11 The typical dog is an adult, with a median age of about 5 years.¹ It is not considered contagious.¹

What Causes HGE?

The cause isn't fully proven. The leading theory is that Clostridium perfringens, a bacterium found in many dogs' guts, produces toxins (especially one called netF) that damage the intestinal lining and its blood vessels. Fluid, protein and red blood cells then leak into the gut.^1,3,2

• In one study of gut biopsies, 9 of 10 dogs with AHDS had severe damage to the intestinal lining, and all 5 bacterial samples tested carried the netF gene.²
• Not every affected dog carries the toxin gene, and some healthy dogs do, so researchers still don't know whether the bacteria cause the disease or flourish because of it.^8,11

The sources we reviewed name no food, stress or other trigger that owners could have prevented. AHDS strikes otherwise healthy dogs suddenly, so it isn't something you did.³

How Vets Diagnose HGE

There's no single test for AHDS. Vets diagnose it from the sudden signs and typical blood results, after ruling out other causes.¹

• Packed cell volume (PCV): most dogs have a very high red cell count, often above 60%, because they've lost so much fluid. Total protein is normal or low.^1,3 This pairing is an important clue.
• Other tests: a full blood count, chemistry panel, urine test, fecal tests (including a parvovirus test), X-rays or ultrasound, and clotting tests if bleeding seems prolonged.^3,1

Conditions that can look similar include parvovirus, whipworms and hookworms, Addison's disease, rat poison and other clotting problems, stomach or gut ulcers, pancreatitis, cancer and a perforated gut.¹

HGE or Parvo?

See parvo in dogs.

Treatment

• IV fluids are the core treatment. They replace lost fluid and electrolytes quickly. Fluids under the skin are usually not enough.^1,3
• Supportive care: anti-nausea medicine, a stomach protectant, pain relief, and plasma or other fluids that hold water in the blood vessels if protein is very low.^3,1
• Food: small amounts of an easily digested diet, restarted as your vet directs.¹
• Probiotics: in a small trial without antibiotics, dogs given a probiotic and dogs given a placebo both recovered quickly, with no significant difference in clinical scores between the groups.¹² The 2024 European guideline neither recommends nor rules out probiotics.⁶

Why Most Dogs Don't Need Antibiotics

Antibiotics used to be routine for HGE. They're no longer recommended for mild to moderate cases.^3,1,6 Studies found they didn't improve survival or speed recovery, bacteria in the blood were no more common in affected dogs than in healthy ones, and antibiotics left the gut bacteria more disturbed weeks later.^5,13,9 Your vet will still use injectable antibiotics if your dog shows signs of a body-wide infection (sepsis), such as a very high or very low white cell count, or is severely ill.^1,11

Fecal microbiota transplant (FMT), which means giving stool from a healthy donor dog, is being studied. In trials it worked about as well as supportive care alone or a probiotic.^9,14

Recovery and Survival

With hospital care, more than 9 in 10 dogs survive. Merck puts the death rate at under 10% in hospitalized dogs.^1,4 The risk is much higher if treatment is delayed, because dogs can develop shock, a body-wide clotting disorder (DIC) or sepsis.^1,3

• Many dogs improve within a day of starting IV fluids.¹⁰
• The usual hospital stay is about 3 days, with a range of 1 to 7.¹¹
• Signs usually resolve within a few days with supportive care.³

At home afterward, keep your dog rested, feed small bland meals as your vet directs and keep them apart from other dogs while they're unwell.¹⁰ Call your vet if bloody diarrhea, vomiting or lethargy returns.

A mild case may be managed at home, but that decision belongs to your vet. AHDS ranges from dogs well enough to treat at home to dogs needing intensive care.¹⁵

How Much Does HGE Treatment Cost?

We found no published average. In two US pet insurance claims, a two-day hospital stay with IV fluids cost about $1,500 and $1,630.^16,17 These are single examples (one from 2019, one undated). Costs vary widely with severity, length of stay, clinic and region.

Frequently Asked Questions

Can a dog survive HGE without treatment?

Untreated AHDS can be fatal, and dogs can go into shock before they look dehydrated. Don't wait. Call your vet or an emergency clinic.

How long does HGE last in dogs?

Most dogs improve within a day of starting IV fluids and go home after about 2 to 4 days. Signs usually resolve within a few days.

What does HGE poop look like?

Large amounts of bright red, jelly-like diarrhea, often described as raspberry or strawberry jam. It often comes after vomiting.

How did my dog get HGE?

The cause isn't proven. Toxins from a common gut bacterium, Clostridium perfringens, are the leading suspect. It isn't contagious, and no preventable trigger has been found.

Is HGE contagious to other dogs?

No, it isn't considered contagious. Parvovirus, which can look similar, is highly contagious, so your vet may test for it.

Can HGE come back?

We found no reliable data on whether or how often AHDS comes back. Go back to your vet promptly if signs return.

Does my dog need antibiotics for HGE?

Usually not. Studies show antibiotics don't speed recovery in most dogs. Vets keep them for dogs with signs of a body-wide infection or severe illness.