Splenic abscess is a rare disease with only few reports in small-animal practice as well as in human medicine. It has been mostly reported in immunocompromised patients or following penetrating foreign bodies. This report aims to add to the current veterinary literature on recommended diagnostic tools for splenic abscess, as well as to provide follow-up findings after successful surgical treatment. An 8-year-old male German shepherd dog was admitted to the clinic for evaluation of fever, anorexia, and lethargy for the previous 3 days. During the physical examination, a mass was palpated in the left cranioventral abdomen. Diagnostic imaging including radiography and ultrasonography revealed the presence of a large mass in the spleen and signs of peritonitis. Laboratory tests reflected highly septic pyogranulomatous inflammation and, together with imaging findings, raised a high suspicion of splenic abscess and septic peritonitis. Therapy included complete splenectomy and placement of peritoneal drainage. Bacteriological examination revealed severe infection with Staphylococcus epidermidis and S. pseudintermedius. Histopathological evaluation of the mass confirmed the diagnosis of splenic abscess. Early diagnosis of splenic abscess in small animals requires a high level of suspicion based on clinical and ultrasonographic findings. Immediate surgical intervention is preferable and confirms the diagnosis. Total splenectomy remains the most effective therapy. Although there are many predisposing factors for splenic abscess, the true etiology remains obscure.

Acute abdomen syndrome is an emergency in small animal practice that requires rapid diagnosis to determine the appropriate treatment. No studies have correlated the preoperative abdominal ultrasonography (US) findings with the clinical, surgical, cytopathologic, and histopathologic findings. This retrospective study was designed to evaluate abdominal US in the diagnosis of acute abdomen syndrome using surgery as a “criterion standard”. The most frequently misinterpreted lesions with US were also identified. The study included 50 dogs and cats with physical examination, an US diagnosis, US guided fine-needle aspiration cytology, intraoperative findings, and histopathology. Intraoperatively, 49 primary and 43 secondary lesions were identified. The sensitivity, specificity, and positive and negative predictive values for US were calculated. There was a good agreement between the US diagnosis and intraoperative findings of 86.9% (80/92), for both primary and secondary lesions (p < 0.0001). Cytology and histopathology examinations corroborated the US in 86.4% (n = 64/74) of primary and 66.2% of secondary (n = 49/79) lesions. Using US as the “criterion standard”, the sensitivity of abdominal palpation for identification of ascites and masses was 32.4% and 43.7%, respectively, while the specificity was 93.7% and 94.4%, respectively. Abdominal US is a useful preoperative modality for diagnosing acute abdominal diseases in dogs and cats. Care should be taken with interpretation of gastrointestinal perforation, omental tumors, and common bile duct rupture, as these lesions are frequently misinterpreted with US.