Dog has bloody diarrhea and vomiting but acting normal

What is acute hemorrhagic diarrhea syndrome?

AHDS can affect any breed, age, size, or gender but it is most common in small and toy breed dogs. Young Miniature Poodles, Miniature Schnauzers, and Yorkshire Terriers seem to be more commonly affected. Other breeds commonly affected include the Pekingese, Dachshund, Maltese, Cavalier King Charles Spaniel, Bichon fries, Shetland Sheepdog, and Poodle.

What causes AHDS?

The exact cause of AHDS remains unknown but there are several possible contributing factors, such as the bacteria Clostridium perfringens, dietary indiscretion (ingesting non-food items or different foods), immune-mediated disease, toxins, or pancreatitis. Stress, anxiety, and hyperactivity are thought to be possible contributing factors in many cases.

Other possible causes of AHDS include:

• Stomach or intestinal ulcers
• Trauma
• Gastrointestinal tumors or obstruction
• Foreign bodies
• Infectious diseases (i.e., canine parvovirus infection)
• Coagulation (blood clotting) disorders
• Intestinal parasites or bacteria

Recent research indicates that AHDS may be an allergic reaction (food or inhaled). Dogs who experience AHDS may be more prone to developing AHDS again in the future.

How is AHDS diagnosed?

The diagnosis of AHDS can be challenging and may ultimately require intestinal biopsies in persistent cases. Because there are so many possible causes of AHDS, evaluation usually requires a complete blood count (CBC), biochemical analysis of the blood, urinalysis, radiographs (X-rays), coagulation tests, fecal evaluation, and ultrasound or endoscopic examination of the gastrointestinal tract.

"Diagnosis is often a process of eliminating other causes of bloody stools and gastrointestinal distress."

The packed cell volume (PCV) or hematocrit (HCT)—a measurement of the proportion of red blood cells in the blood—is often greater than 60% in dogs with AHDS. Most dogs have a normal HCT of 37% to 55%. An elevated HCT in combination with a low or normal total protein is an important clue that a dog may have AHDS. Blood bicarbonate levels, blood pH levels, and serum chemistries also give indicators that AHDS may be present.

Diagnosis is often a process of eliminating other causes of bloody stools and gastrointestinal distress.

How is AHDS treated?

Dogs with AHDS will appear severely ill and, if left untreated, may die. In most cases, the disorder appears to run its course in a few days if the dog is given appropriate supportive care. Intravenous fluid therapy with potassium and electrolyte supplementation provides the foundation of AHDS therapy. Subcutaneous fluids (fluids given under the skin) are not usually considered adequate to meet the significant fluid requirements of most dogs with AHDS. Most dogs are not fed during the first 24 hours of treatment and are often given antibiotics to combat potential secondary intestinal infection.

Additional therapy for AHDS may include gastrointestinal protectants, such as sucralfate (Carafate®, Sulcrate®), and anti-vomiting medications, such as maropitant (Cerenia®). In severe cases, plasma (the liquid portion of blood) or colloids may be needed to correct severely low blood protein levels. Probiotics and pain medications are also sometimes used in the treatment of this condition.

"If intravenous fluid therapy is not given, the dog’s red blood cell count will continue to elevate because of dehydration."

If intravenous fluid therapy is not given, the dog’s red blood cell count will continue to elevate because of dehydration. In this situation, the dog is at risk for a potentially fatal clotting disorder called disseminated intravascular coagulation (DIC). Once DIC has begun, it is often irreversible and may result in death.

Can AHDS be prevented?

Since the cause is unknown, it is difficult to give advice on prevention. However, reasonable suggestions are to feed a high-quality commercial diet, refrain from giving your dog extra foods or treats your dog is not accustomed to, use parasite preventive medications as directed by your veterinarian, and generally provide a low-stress environment.

Diarrhea. It's bad enough when a pet has stinky loose stools, but when they're mixed with bright red blood — or a pet strains to defecate and produces blood only — even the most sanguine pet owner becomes concerned.

Causes of bloody diarrhea can include small, harmless masses; major tumors; toxic substances; or simply emotional upset. Fortunately, it's rarely an emergency unless the dog is losing enough blood to cause significant anemia or if the dog is bleeding out of the gastrointestinal tract because of a toxin such as rat poison or a systemic disease, says Craig B. Webb, veterinarian, professor of small animal medicine at Colorado State University's Veterinary Teaching Hospital in Fort Collins.

Sometimes the cause is never clear. That has been the case with my dog Keeper, whose digestive system is sensitive, to say the least. Usually, his veterinarian prescribes antibiotics and a few days of a bland diet. But recent studies show that in some cases, symptomatic treatment — a bland diet to soothe the digestive tract — is all that's needed.

Approximately 50% to 60% of dogs with acute onset of bloody diarrhea have fecal samples that are positive for a toxin called netF, produced by Clostridium perfringens bacteria. While many healthy dogs have C. perfringens as a normal part of their gut microbiome, in dogs with bloody diarrhea, C. perfringens bacteria are producing the netF toxin gene. The trigger may be something the dog has eaten, infection from another organism or some other cause.

"What makes a strong case that it might be causative is that only dogs with hemorrhagic diarrhea are positive for this toxin," says Texas A&M researcher Jan S. Suchodolski, veterinarian and one of the authors of a study on the association of C. perfringens and netF toxin genes with acute hemorrhagic diarrhea published last November in the Journal of Veterinary Internal Medicine. "We don't typically see it in dogs with acute non-hemorrhagic diarrhea or with chronic diarrhea."

Dogs who are positive for the toxin, which can be identified through a molecular test, usually eliminate it quickly, independent of treatment with antibiotics, Suchodolski said.

Why no antibiotics?

Antibiotics can have a significant effect on intestinal microbiota — the "good bugs" that populate the intestine and play an important role in physiology, metabolism, nutrition and immune function. Broad-spectrum antibiotics disrupt the gut's microbiome, killing beneficial bacteria.

"We're discovering more and more that these effects are long-lasting," Suchodolski said. "And dogs don't recover quicker compared to not getting antibiotics for acute diarrhea."

That doesn't mean you don't need to be concerned if your dog is pooping out blood. Small dogs with what is now called acute hemorrhagic diarrhea syndrome — formerly known as hemorrhagic gastroenteritis — can quickly become dehydrated, especially if diarrhea is accompanied by vomiting. A small fraction of dogs may go into shock or sepsis from dehydration and infection, and this may require hospitalization or antibiotics.

Signs that your dog should see the veterinarian as soon as possible include vomiting, lack of appetite, dehydration, increased heart rate and respiration and collapse.

If your dog has bloody diarrhea but is otherwise normal and alert, withhold food for 12 to 24 hours and then feed a bland diet for a few days. Ensuring that the dog is drinking water is more critical than getting him to eat, Webb said.

"At some point, probiotic therapy should be considered, as changing the gut microbiota may help long term," said Joseph W. Bartges, veterinarian and professor of internal medicine and nutrition at the University of Georgia's College of Veterinary Medicine.

Don't hesitate to call your veterinarian if you're worried. "If there are any concerns, especially if your pet feels bad and is not him or herself, you should take them to a veterinarian," Bartges said. "It is better to be safe than sorry."

Pet Connection is produced by a team of pet-care experts headed by veterinarian Marty Becker and journalist Kim Campbell Thornton of Vetstreet.com. Joining them is dog trainer and behavior consultant Mikkel Becker.

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