Ultrasonographic Features and Associated Clinical Findings in 21 Dogs With Histologically Confirmed Abscessed and Non-Abscessed Splenitis.

Splenitis, both with and without abscess formation, is an uncommon and potentially life-threatening diagnosis in dogs, occurring either as an isolated condition or secondary to other systemic inflammatory/infectious diseases. This retrospective descriptive study describes the ultrasonographic features of histopathologically confirmed splenitis in 21 dogs, including 12 cases of abscessed splenitis and 9 cases of non-abscessed splenitis (7 neutrophilic and 2 fibrinous-suppurative). Clinical signs were variable, most frequently including lethargy, anorexia or hyporexia, and vomiting; fewer dogs presented with fever. Hematologic and chemistry findings were consistent with systemic inflammation in most cases. The most common splenic ultrasound findings were a cavitated, hypoechoic, or mixed echogenicity mass; splenomegaly with diffusely heterogeneous parenchyma, and hypoechoic, non-cavitated nodules. Cavitated splenic masses were more often associated with abscessed splenitis, whereas diffuse parenchymal changes with multiple nodules were more commonly seen in cases of non-abscessed splenitis. Additionally, hyperechoic peritoneal fat (steatitis) was observed in all dogs with abscessed splenitis, and peritoneal effusion was also frequently present. In cases of non-abscessed splenitis, concurrent inflammatory or infectious disease in other abdominal organs was always present and often considered the underlying cause. All dogs underwent splenectomy, in addition to other surgical procedures in some cases. Short-term postoperative prognosis was favorable, with 18 out of 21 dogs surviving to discharge. These findings suggest that splenitis should be included among differential diagnoses in dogs with compatible clinical, laboratory, and imaging features.