Retrospective evaluation of the incidence and outcome of neutropenia in dogs with acute hemorrhagic diarrhea syndrome (2017-2022): 54 cases.

Objective: To report the occurrence of neutropenia in dogs with suspected acute hemorrhagic diarrhea syndrome (AHDS) and to assess its association with survival. Secondary objectives were to assess whether neutropenia was associated with length of hospitalization, fulfillment of systemic inflammatory response syndrome (SIRS) criteria, and whether SIRS status was associated with survival. Finally, the association of antimicrobial use with neutropenia, SIRS status, and survival was evaluated.

Design: Single-center, retrospective study from the medical records of dogs diagnosed with AHDS between 2017 and 2022.

Setting: Private referral hospital.

Animals: Fifty-four dogs with suspected AHDS referred to the Emergency and Critical Care specialist service.

Interventions: None.

Measurements and main results: Of 54 dogs, 28 (52%) presented with or developed neutropenia during their treatment course. Overall, 9 (17%) dogs were nonsurvivors. A total of 8 of 28 (29%) dogs with neutropenia were nonsurvivors, while only 1 of 26 (4%) dogs with a normal neutrophil count was a nonsurvivor (P = 0.025). Upon hospital admission, neutropenic dogs were significantly more likely to fulfill SIRS criteria than nonneutropenic dogs (P = 0.0096). There was no difference in mortality between SIRS-positive (fulfilling ≥2 SIRS criteria) and SIRS-negative (fulfilling <2 SIRS criteria) dogs (P = 0.14). There was no difference in the median length of hospitalization between neutropenic and nonneutropenic dogs (P = 0.49).

Conclusions: The incidence of neutropenia is high in this population of dogs presenting with AHDS. In this retrospective study, neutropenia was significantly associated with an increased risk of nonsurvival and an increased likelihood of fulfilling SIRS criteria; however, a fulfillment of SIRS criteria could not be used to predict survival. Neutropenia in dogs with AHDS was not associated with an increased length of hospitalization.