Transdiaphragmatic Hepatic and Pulmonary Abscess Attributed to Ileal Diverticulitis in a Horse

Abstract

A 16-year-old, 473-kg, Thoroughbred mare was referred to the Cornell University Hospital for Animals with a 1-year history of chronic cough, halito-sis, weight loss, and lethargy. Nine months earlier, the mare had been treated for a bacterial or viral respiratory infection with a course of potentiated sulfona-mides. During the 6-week treatment period, the owner reported that the horse had decreased appetite and had lost weight but that the respiratory signs seemed improved. More recently, over the last 2-3 months, the mare exhibited intermittent respiratory signs, inap-petence, and weight loss. On presentation, the mare (body condition score 4/9) was alert and responsive and had a normal rectal temperature (100.6°F) and heart rate (40 beats/min), but was tachypneic (32 breaths/min). Her mucous membranes were pink and capillary refill time was normal (<2 seconds). During the examination, a non-productive cough occurred intermittently and was associated with foul-smelling breath. Cardiothoracic auscultation was normal and a rebreathing examination disclosed decreased lung sounds in the cranioven-tral lung fields. Auscultation of abdomen was normal. Clinical laboratory tests identified the presence of mature neutrophilia (7.2 9 10 3 /lL; reference range, 2.7-6.6 9 10 3 /lL), hyperproteinemia (9.7 g/dL; reference range, 5.7-7.7 g/dL), hyperglobulinemia (7.1 g/dL; reference range, 2.4-4.4 g/dL), hyperfibrinogenemia (400 mg/dL; reference range, 0-200 mg/dL), and hypo-albuminemia (2.8 g/dL; reference range, 3-3.7 g/dL). Red cell indices (HCT, RBC numbers, MCV, RDW) were within normal limits. Serum electrolyte concentrations (sodium, potassium, chloride, calcium, and phosphorus) were normal, and CK and AST activities were decreased (95 and 161 U/L, respectively; reference range CK, 142-548 U/L; reference range AST, 199-374). Serum creatinine concentration, hepatic enzyme activities (SDH, GLDH, GGT), and serum bilirubin (indirect, direct) concentrations also were within the reference range. Thoracic radiography disclosed the presence of 3 lesions: Cranio-ventrally, there was lung consolidation and air bronchograms consistent with pneumonia. Caudo-dorsally, there was a single, oval, well-margined, soft tissue opacity that spanned 4 intercostal spaces and silhouetted with the diaphragm. Because this lesion silhouetted with the diaphragm, its abdominal extension could not be confirmed by radiography. Cranio-dorsally, within the abdomen and close to the diaphragm, were 2 well-marginated structures with fluid-gas interfaces that spanned 4 intercostal spaces (Fig 1). Based upon the radiographic findings, the gas accumulations were considered to represent abscesses within the liver or gas-filled segments of bowel. Tho-racic sonography confirmed the presence of bilateral ventral lung consolidation consistent with pneumonia. The caudo-dorsal lung lesion, visible on radiographs, was not observed on ultrasound examination because it was surrounded by aerated lung. Sonography of the right cranio-dorsal abdomen confirmed that the liv...