Small intestinal pseudodiverticulosis in a pony mare.

The study examines a case where a 14-year-old pony mare exhibited symptoms of illness such as persistent fever, loss of appetite, weight loss, and changes in stool consistency for thirty days. Upon examination, numerous pseudodiverticula, or false diverticula, were discovered in the small intestine, leading to a conclusion that they should be considered as a potential cause of similar symptoms in horses.

Case Summary and Diagnostic Methods

• The subject of this study was a 14-year-old mare suffering from a range of symptoms including high temperature, lack of appetite, weight loss, and changes in manure consistency for a month.
• A physical check revealed an identifiable but movable mass in her ventral abdominal area. Transabdominal ultrasonography, a medical imaging technique using ultrasound waves, unveiled a cluster of distended, reduced motion, and thick-walled small intestine loops closely grouped with defined, over-reflective (hyperechoic) masses.
• A large amount of echogenic (able to return an ultrasound echo) peritoneal fluid was discovered – a fluid-filled abdominal cavity. Removal and analysis of this fluid revealed a mix of neutrophilic and macrophagic exudate, or inflammatory drainage, and various bacteria were found.

Case Outcome and Autopsy Findings

• Given the poor prognosis, the mare was euthanized. The examination post-death revealed a significant abdominal abscess, blood-tinged peritoneal fluid containing fibrin strands, and approximately 50 outpouches extending from the internal side (anti-mesenteric aspect) of the duodenum, jejunum, and ileum, which are parts of the small intestine.
• These structures were labelled as pseudo diverticula based on the histological examination which showed the absence of the tunica muscularis layer, a muscular layer of the intestinal wall, implying they were not true diverticula.

Implications and Recommendations

• Pseudodiverticula should be included in differential diagnosis for horses displaying clinical symptoms consistent with colic, diarrhea, or weight loss. If an examination reveals one or more structured masses, or the visualization of small intestinal loops with thickened walls, possible pseudodiverticula should be considered.
• Transabdominal ultrasound can be an effective tool for diagnosing such cases. Proper diagnostic techniques are crucial for accurate identification of disease and subsequent treatment strategies.