Veterinary professionals learn to deduce the cause of a canine’s bloody belly
With how frequently hemoabdomen (or bloody belly) is researched in the veterinary space, Steven Berkowitz, DVM, DACVECC, maintains that an accurate diagnosis is extremely individual and case dependent. “You will have some dogs walking into your hospital, wagging their tails, that may be just a little bit off vs a dog that is poorly responsive, with a heart rate through the roof and that is pale as a ghost,” Berkowitz said to attendees at the recent Directions in Veterinary Medicine symposium in Arlington, Virginia.1
Through his work as a criticalist at NorthStar VETS in Robbinsville, New Jersey, as well as his research and published works on the topic, Berkowitz has become an accredited expert on all facets of hemoabdomen, also called hemoperitoneum, in dogs. Ultimately, understanding the physiology, pathophysiology, and history of the canine patient will help guide therapy and supportive actions to improve outcomes, he assured his audience.
Multiple sources for acute bleeding exist within the abdominal peritoneum, including organs, vessels, and the peritoneal lining itself, Berkowitz explained. In dogs, the most prevalent sources are splenic, hepatic, and adrenal vascular leakage.
Neoplasia is the most common cause of acute nontraumatic hemoabdomen in the adult canine. Reports indicate that most canine patients with hemoabdomen will have a ruptured abdominal mass, and many of those patients have metastatic hemangiosarcoma, according to Berkowitz. These patients are often medium to large dog breeds with ruptured splenic or hepatic hemangiosarcoma, although smaller breeds will also present with the same diagnosis.
Beyond neoplasia, coagulopathy must be considered in all ages and breeds. This includes both acquired (eg, toxins, iatrogenic, consumption) and hereditary (eg, hemophilia, von Willebrand disease, other factor deficiencies) conditions, Berkowitz explained.
He recommended one quick question that veterinarians can ask clients to rule out whether the cause might be congenital: Does your dog tend to bleed a lot when it breaks a toenail or is poked with something sharp? This might trigger the client to remember that the dog bled for 2 hours the last time it broke a toenail. “I’m then going to change my approach to working with that hemoabdomen,” he said.
Trauma to the abdomen is another familiar cause Berkowitz has witnessed. “In [humans], if you have blood in the belly from trauma, you are going to the operating room. I truly cannot remember the last time I had a traumatic hemoabdomen go into surgery. I have known fractured livers, spleen lacerations, and even kidney ruptures, but they almost never go to surgery,” he said.
More recently, anaphylaxis is touted as another frequent cause of hemoperitoneum. Berkowitz said he suspects it has always been a cause, but the technology that is now readily available to hospitals has led to more diagnoses and supportive medical literature. “Usually, anaphylaxis reactions leading to hemoabdomen are very low volume,” he said. There is debate regarding the mechanism of action; however, it is likely the result of acute portal hypertension, leading to oozing blood and/or diapedesis.
Patients with hemoabdomen frequently present as acutely ill and in shock, secondary to rapid intravascular volume depletion, Berkowitz explained. The actual bleeding may be imperceptible because of the internal nature of the condition. Therefore, physical examination becomes more nuanced and will focus on vitals rather than visually apparent blood loss.
“We have gotten so technologically advanced that we sometimes forget to touch and look at our patients,” Berkowitz said. He urged attendees to remember to physically examine the patient before reaching for any ancillary tools, as initial presentation and triage will help to reduce the scope of exploration and zero in on likely causes. It is by far the most significant piece of correctly diagnosing the patient, he reiterated.
Limiting the examination to the belly would be a grave disservice, Berkowitz warned. If a patient presents with suspected hemoabdomen, he instructed to look at the chest—especially in hospitals, where a point-of-care ultrasound exam is feasible. “If I have a 9-year-old pit bull with blood in its abdomen, and I move my probe over, and it also has pericardial effusion, I am way less comfortable [treating this patient] than a patient that only has fluid in its belly,” he said.
Often, patients with hemoabdomen will be in cardiovascular or distributive shock and will be tachycardic with poor pulses and frequent dropped heartbeats. If the cardiac output is altered by reduced stroke volume (from blood loss), the only way to improve stability is to raise the heart rate itself, Berkowitz advised.
“If you have the option to obtain blood pressure, get the blood pressure,” he said. It will help determine whether the shock index (heart rate/blood pressure) is very high, in which case it becomes imperative to shift attention to improving perfusion and reducing ongoing shock.
“No matter the cause of the hemoabdomen, the focus must be on rapidly reducing the signs of shock,” Berkowitz said. Doing so will not only improve the nature of the disease, but it will also help prevent secondary organ dysfunction, including acute kidney injury and continued cardiovascular collapse.
He also stressed the importance of pain medication as a necessity for stabilization. “When possible, pure μ opioids are preferred, [as] naloxone can reverse concerns that arise. Methadone, fentanyl, and morphine are ideal, but if buprenorphine is all that is available, this is [also] acceptable,” Berkowitz said.
A patient’s medical history will be the next vital component to achieving an accurate diagnosis. As Berkowitz explained, neoplasia would be a chief concern if an older dog is brought to the hospital with pallor and shock after suddenly collapsing during a routine walk. If a young patient was on a walk but then began to yelp and favor a particular paw before it collapsed, anaphylaxis must be on the radar.
Additional tests recommended for hemoabdomen include obtaining a packed cell volume (PCV)/total solids (TS) test of the patient and comparing it with the fluid. This is often an indication of an acute bleeding episode. Berkowitz laid out a hypothetical example of a patient with a PCV of 25%, and 30% ascites. He concluded that this is blood and not serohemorrhagic in nature, as opposed to blood-tinged fluid with a 3% PCV. This comparison is a simple and inexpensive way to confirm or deny the diagnosis of hemoperitoneum. When obtaining PCV/TS results, it is also appropriate to consider performing a complete blood test to assess for platelet counts, Berkowitz added. Serum biochemistry is helpful, especially if assessing for hepatic involvement, but it is not imperative in the early stages of diagnosis.
A patient’s prognosis is directly linked to the underlying cause, with neoplasia presenting the least favorable outcome. Even with surgical intervention and chemotherapy, the median survival rate is 3 to 6 months. In those instances, Berkowitz said the client should be provided with as much information about the diagnosis as possible to allow them to make the best decision for their beloved family member early on.
If the hemoabdomen is the result of trauma or anaphylaxis, the prognosis is positive, barring any unforeseen issues. Berkowitz is confident that rapid identification of the hemoabdomen and concurrent prevention of ongoing blood loss, as well as the improved perfusion associated with resolving shock, are the best ways to improve patient outcomes. Once identified, constant monitoring and altering therapy based on their status will also enhance the odds of recovery.
Berkowitz S. “Bloody belly” diagnosis and stabilizing the hemoabdomen. Presented at: Directions in Veterinary Medicine; April 21-22, 2023; Arlington, VA.