title: Effect of Clostridium botulinum toxin type A injections into the deep digital flexor muscle on the range of motion of the metacarpus and carpus, and the force distribution underneath the hooves, of sound horses at the walk.
abstract: In the treatment of laminitis, reducing deep digital flexor muscle (DDFM) activity might diminish its pull on the distal phalanx, thereby preventing displacement and providing pain relief. Injection of Clostridium botulinum toxin type A into the DDFM of horses is potentially therapeutic. However, the effects of C. botulinum toxin type A on the gait characteristics of sound horses at the walk are not known. The aim of this study was to test if a reduced DDFM activity would lead to (1) alterations of the sagittal range of motion of the metacarpus (SROM) and range of motion of the carpal joint (CROM); (2) changes in the force distribution underneath the hoof (toe vs. heel region: balance index); and (3) changes in the force distribution between the treated and untreated limb (symmetry index). The DDFMs of the left forelimbs of seven sound Royal Dutch Sport Horses were injected with 200 IU C. botulinum toxin type A using electromyography and ultrasound guidance. Measurements using an inertial sensor system and dynamically calibrated pressure plate were performed before and after injections. The SROM and CROM of the treated limb were significantly increased after C. botulinum toxin type A injections. No significant changes were detected in the balance index or in the symmetry index, indicating that no lameness was induced. C. botulinum toxin type A injections into the DDFM of sound horses do not appear to result in substantial gait alterations at the walk.
authors.affiliation: Department of Equine Sciences, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 114, 3584 CM Utrecht, The Netherlands.
authors.forename: Lotte C
authors.initials: LC
authors.lastname: Hardeman
authors.affiliation: Department of Equine Sciences, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 114, 3584 CM Utrecht, The Netherlands.
authors.forename: Bram R
authors.initials: BR
authors.lastname: van der Meij
authors.affiliation: Department of Surgery and Anaesthesiology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium.
authors.forename: Maarten
authors.initials: M
authors.lastname: Oosterlinck
authors.affiliation: Division of Diagnostic Imaging, Department of Companion Animal Sciences, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 108, 3584 CM Utrecht, The Netherlands.
authors.forename: Stefanie
authors.initials: S
authors.lastname: Veraa
authors.affiliation: Department of Equine Sciences, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 114, 3584 CM Utrecht, The Netherlands.
authors.forename: Johannes H
authors.initials: JH
authors.lastname: van der Kolk
authors.affiliation: Department of Equine Sciences, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 114, 3584 CM Utrecht, The Netherlands. Electronic address: i.d.wijnberg@uu.nl.
authors.forename: Inge D
authors.initials: ID
authors.lastname: Wijnberg
authors.affiliation: Department of Equine Sciences, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 114, 3584 CM Utrecht, The Netherlands; Department of Surgery and Anaesthesiology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium.
authors.forename: Willem
authors.initials: W
authors.lastname: Back
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D019274:Botulinum Toxins, Type A / Q000494:pharmacology*; D002350:Carpus, Animal / Q000187:drug effects* / Q000502:physiology; D006724:Hoof and Claw; D006736:Horses / Q000502:physiology*; D008663:Metacarpus / Q000187:drug effects* / Q000502:physiology; D009465:Neuromuscular Agents / Q000494:pharmacology; D011312:Pressure; D016138:Walking / Q000502:physiology*
chemical_list: D009465:Neuromuscular Agents; D019274:Botulinum Toxins, Type A
keywords: Clostridium botulinum toxin type A; Deep digital flexor muscle; Equine; Laminitis