Anaphylactic Hemoperitoneum in Dogs

Editor's note: The initially published version of this article erroneously noted elevated ALP as a clinical sign of anaphylaxis. This has been corrected to elevated ALT as of March 30, 2023.

In the Literature

Hnatusko AL, Gicking JC, Lisciandro GR. Anaphylaxis-related hemoperitoneum in 11 dogs. J Vet Emerg Crit Care (San Antonio). 2021;31(1):80-85.

The Research …

Common signs of anaphylaxis in dogs include hemorrhagic gastroenteritis, hepatic congestion, gallbladder wall edema, increased liver enzyme activity, hemoconcentration, cutaneous manifestations (eg, hives), and, in severe cases, acute cardiovascular collapse and death. 

This retrospective case series describes hemoperitoneum, a less common complication of anaphylaxis. Coagulopathy of anaphylaxis is rare, and patients are presented with nontraumatic hemoperitoneum. This multifactorial phenomenon is poorly understood and has only been described twice in veterinary and once in human medicine literature.^1-3 

Eleven previously healthy dogs with acute onset of clinical signs consistent with anaphylaxis and with confirmed hemoperitoneum were presented after collapse or acute weakness. No dogs had cutaneous manifestations or pleural, pericardial, or pulmonary fluid accumulation. Most dogs exhibited concurrent GI signs, 4 dogs had hypoglycemia, and 5 dogs had coagulopathy that was confirmed by blood work.

Treatment varied among patients and included epinephrine, fluid therapy, diphenhydramine, famotidine, and glucocorticoids. Eight dogs received fresh frozen plasma, and 2 dogs required RBC transfusion. 

Anaphylactic hemoperitoneum should be considered in cases of nontraumatic hemoperitoneum with no clear cause and concurrent clinical signs of anaphylaxis (eg, distributive shock, elevated ALT, gallbladder halo sign on ultrasound indicative of gallbladder wall edema). 

The need for fresh frozen plasma and RBC transfusion in this case series suggests that early identification of anaphylactic coagulopathy and hemoperitoneum can improve treatment decisions and outcome.

… The Takeaways

Key pearls to put into practice:

• Approximately 20% of patients presented with anaphylaxis do not show dermal signs⁴; therefore, lack of dermal manifestations should not exclude anaphylaxis as a differential diagnosis in patients with other clinical signs of anaphylaxis.

• Nontraumatic hemoperitoneum is a documented complication of anaphylaxis, which should be a differential diagnosis when hemoperitoneum is present along with gallbladder halo sign, elevated ALT, and GI signs.

• Medical management of anaphylactic hemoperitoneum consists of epinephrine and fluid therapy. Surgery is contraindicated. Addition of H₁-receptor antagonists (eg, diphenhydramine), H₂-receptor antagonists (eg, famotidine), glucocorticoids, and blood products should be based on individual patient parameters.