title: Injury to the origin of the gastrocnemius muscle as a possible cause of lameness in four horses.
abstract: Four horses were evaluated because of hind limb lameness. Two had a distinct gait abnormality at the walk characterized by lateral rotation of the point of the calcaneus and medial rotation of the toe during the stance phase. Nuclear scintigraphy revealed a focal area of intense radioisotope uptake in the caudodistal aspect of the femur in all 4 horses, and 3 of the horses had a corresponding proliferative reaction on the caudodistal cortex of the femur on radiographs. In all 4 horses, a diagnosis of injury to the origin of the gastrocnemius muscle was made. Three of the horses returned to athletic endeavors after an extended period of rest and a gradual return to exercise. The fourth improved after 5 months of rest but became lame again when returned to exercise and was euthanatized.
authors.affiliation: Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Washington State University, Pullman 99164, USA.
authors.forename: T M
authors.initials: TM
authors.lastname: Swor
authors.forename: R K
authors.initials: RK
authors.lastname: Schneider
authors.forename: M W
authors.initials: MW
authors.lastname: Ross
authors.forename: E J
authors.initials: EJ
authors.lastname: Hammer
authors.forename: R L
authors.initials: RL
authors.lastname: Tucker
mesh_terms: D000818:Animals; D005260:Female; D005269:Femur / Q000293:injuries; D005684:Gait; D006734:Horse Diseases / Q000175:diagnosis / Q000209:etiology*; D006736:Horses / Q000293:injuries*; D007794:Lameness, Animal / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000209:etiology*; D008297:Male; D018482:Muscle, Skeletal / Q000000981:diagnostic imaging / Q000293:injuries*; D011877:Radionuclide Imaging; D013669:Technetium Tc 99m Medronate
chemical_list: D013669:Technetium Tc 99m Medronate