Imaging diagnosis--muscular hypertrophy of the small intestine and pseudodiverticula in a horse.

A 14-year-old Thoroughbred gelding was presented for chronic colic and weight loss. Transcutaneous and transrectal abdominal ultrasonography revealed distended, thickened small intestine with primary thickening of the muscularis and a focally more thickened loop with an echoic structure crossing the wall from the mucosa to the serosa. Visualization of diffuse thickening of the muscularis (muscular hypertrophy of the small intestine) and a focal lesion (pseudodiverticulum) helped clinicians make informed decisions. This case illustrates the importance of transabdominal and transrectal ultrasonography in horses with chronic colic and the relevance of considering the abnormalities in layering pattern of the intestinal wall.

The prevalence of headshaking in horses with primary and secondary dental sinusitis and computed tomographic evidence of infraorbital canal pathology.

BACKGROUND: Sinusitis is a common disease of horses yet there are a limited number of reports in the literature that describe the prevalence of infraorbital canal (IOC) pathology and headshaking behaviour in horses diagnosed specifically with primary sinusitis and secondary dental sinusitis. Given the impact that these behaviours can have on horses' intended athletic use, investigation is warranted. OBJECTIVES: To determine the occurrence of IOC pathology in horses with concurrent primary or secondary dental sinusitis based on computed tomography (CT) findings and to assess whether the frequency of headshaking behaviour is influenced by the presence of IOC pathology. STUDY DESIGN: Retrospective case series. METHODS: Computed tomography studies were assessed for sinusitis (unilateral or bilateral), IOC pathology (unilateral or bilateral) and description of IOC disease including displacement, deformation, periosteal proliferation, hyperostosis, osteolysis and infraorbital nerve exposure. Behaviour outcome was determined by client questionnaire five or more years following CT scan. RESULTS: A total 65 out of 66 horses diagnosed with primary or secondary dental sinusitis demonstrated IOC changes on CT. Hyperostosis (86%), periosteal proliferation (85%) and osteolysis (86%) were common CT findings. Hyperostosis was frequently found to involve both the IOC and supporting bone structure. Five cases were euthanized immediately after CT acquisition or during hospitalisation following diagnostic investigations. Follow-up was obtained in 48/61 cases, with five horses showing headshaking behaviour. MAIN LIMITATIONS: Infraorbital nerve histopathology was not performed. The limited number of cases with no IOC pathology prevented direct comparison between sinusitis groups both with IOC pathology and without IOC changes. The client questionnaire carries a memory bias. CONCLUSION: Computed tomography changes involving the IOC may not predict headshaking behaviours in sinusitis secondary to dental disease. This finding is important in the context that these behaviours render some horses unusable and unsafe for their intended riding discipline.