title: MRI features of gastrocnemius musculotendinopathy in herding dogs.
abstract: Pelvic limb lameness that was localized clinically to the lateral gastrocnemius head was observed in dogs without history of trauma. The aim of this retrospective study was to describe magnetic resonance imaging (MRI) findings of this condition. Nine dogs were identified, eight Border Collies and one Australian Shepherd. They all had chronic pelvic limb lameness; no signs of joint effusion or instability were present. In MR images there was high signal intensity in the lateral head of the gastrocnemius muscle around the sesamoid bone in T2-weighted, T2*-weighted, and STIR images and an iso- to mildly hyperintense signal in T1-weighted images with marked contrast enhancement. The abnormal signal intensity most likely represents a myotendinous strain. The breed affiliation to Border Collies is striking, and a relation to biomechanical forces or motion pattern may be possible. Except for the dog with the most extensive lesion all dogs had an excellent outcome.
authors.affiliation: Department of Clinical Veterinary Medicine, Clinical Radiology, Vetsuisse Faculty, University of Berne, Länggassstrasse 124, Postfach 8466, 3001 Berne, Switzerland. christina.stahl@knp.unibe.ch
authors.forename: Christina
authors.initials: C
authors.lastname: Stahl
authors.forename: Christine
authors.initials: C
authors.lastname: Wacker
authors.forename: Urs
authors.initials: U
authors.lastname: Weber
authors.forename: Franck
authors.initials: F
authors.lastname: Forterre
authors.forename: Paul
authors.initials: P
authors.lastname: Hecht
authors.forename: Johann
authors.initials: J
authors.lastname: Lang
authors.forename: Daniela
authors.initials: D
authors.lastname: Gorgas
mesh_terms: D000818:Animals; D004283:Dog Diseases / Q000000981:diagnostic imaging* / Q000473:pathology; D004285:Dogs; D005260:Female; D006801:Humans; D018810:Magnetic Resonance Angiography / Q000379:methods / Q000662:veterinary*; D018482:Muscle, Skeletal / Q000000981:diagnostic imaging* / Q000473:pathology; D009135:Muscular Diseases / Q000000981:diagnostic imaging / Q000473:pathology / Q000662:veterinary*; D010052:Ovariectomy; D011859:Radiography; D012716:Sesamoid Bones; D013264:Stifle / Q000000981:diagnostic imaging* / Q000473:pathology; D013557:Switzerland; D013710:Tendons / Q000000981:diagnostic imaging* / Q000473:pathology