title: Clinical and endoscopic evidence of progression in 152 cases of equine recurrent laryngeal neuropathy (RLN).
abstract: Examination of the long-term histories and clinical findings was performed in 351 horses suffering from recurrent laryngeal neuropathy (RLN) to examine for possible evidence of progression of this disorder. Fifty-two out of 351 cases (15%) had evidence of progression of the degree of laryngeal dysfunction over a median period of 12 months (range 1.5-48 months) with the onset of progression occurring at median age 7 years. In 30 cases, there was both endoscopic (median deterioration of 3 endoscopic grades; range 1-5 grades) and clinical evidence, with 29 (97%) of these horses concurrently developing sudden-onset, abnormal exercise-related respiratory 'noises' and 13 (43%) concurrently reporting reduced exercise performance. In the remaining 22 horses there was solely clinical evidence of RLN progression, including the sudden onset of abnormal exercise-related respiratory sounds in 16 (73%) and the worsening of such sounds in 6 (23%), associated with reduced exercise performance in 13 (59%) of these 22 cases. Endoscopically, 13 (59%) of the latter 22 cases had marked (total or almost total) RLN that did not appear compatible with their previous exercise-performance histories. This evidence of progression of RLN may be of particular significance in disputes concerning horses that are apparently normal at pre-purchase examination but are later shown to have RLN and also in the surgical treatment of less severe cases of RLN.
authors.affiliation: The Wellcome Trust Centre for Studies in Comparative Respiratory Medicine, The University of Edinburgh, Easter Bush Veterinary Centre, Midlothian, Scotland.
authors.forename: P M
authors.initials: PM
authors.lastname: Dixon
authors.forename: B C
authors.initials: BC
authors.lastname: McGorum
authors.forename: D I
authors.initials: DI
authors.lastname: Railton
authors.forename: C
authors.initials: C
authors.lastname: Hawe
authors.forename: W H
authors.initials: WH
authors.lastname: Tremaine
authors.forename: K
authors.initials: K
authors.lastname: Pickles
authors.forename: J
authors.initials: J
authors.lastname: McCann
mesh_terms: D000818:Animals; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006734:Horse Diseases / Q000503:physiopathology*; D006736:Horses; D007828:Laryngoscopy / Q000662:veterinary; D008297:Male; D010805:Physical Conditioning, Animal; D012009:Recurrent Laryngeal Nerve / Q000503:physiopathology*; D012135:Respiratory Sounds / Q000503:physiopathology / Q000662:veterinary; D014826:Vocal Cord Paralysis / Q000503:physiopathology / Q000662:veterinary*