Packer Rowena M A, Hendricks Anke, Burn Charlotte C
Department of Clinical Science and Services, Royal Veterinary College, University of London, Hertfordshire, AL9 7TA, United Kingdom.
Department of Production and Population Health, Royal Veterinary College, University of London, Hertfordshire, AL9 7TA, United Kingdom.
PLoS One. 2015 May 13;10(5):e0123827. doi: 10.1371/journal.pone.0123827. eCollection 2015.
Concern has arisen in recent years that selection for extreme facial morphology in the domestic dog may be leading to an increased frequency of eye disorders. Corneal ulcers are a common and painful eye problem in domestic dogs that can lead to scarring and/or perforation of the cornea, potentially causing blindness. Exaggerated juvenile-like craniofacial conformations and wide eyes have been suspected as risk factors for corneal ulceration. This study aimed to quantify the relationship between corneal ulceration risk and conformational factors including relative eyelid aperture width, brachycephalic (short-muzzled) skull shape, the presence of a nasal fold (wrinkle), and exposed eye-white. A 14 month cross-sectional study of dogs entering a large UK based small animal referral hospital for both corneal ulcers and unrelated disorders was carried out. Dogs were classed as affected if they were diagnosed with a corneal ulcer using fluorescein dye while at the hospital (whether referred for this disorder or not), or if a previous diagnosis of corneal ulcer(s) was documented in the dogs' histories. Of 700 dogs recruited, measured and clinically examined, 31 were affected by corneal ulcers. Most cases were male (71%), small breed dogs (mean± SE weight: 11.4±1.1 kg), with the most commonly diagnosed breed being the Pug. Dogs with nasal folds were nearly five times more likely to be affected by corneal ulcers than those without, and brachycephalic dogs (craniofacial ratio <0.5) were twenty times more likely to be affected than non-brachycephalic dogs. A 10% increase in relative eyelid aperture width more than tripled the ulcer risk. Exposed eye-white was associated with a nearly three times increased risk. The results demonstrate that artificially selecting for these facial characteristics greatly heightens the risk of corneal ulcers, and such selection should thus be discouraged to improve canine welfare.
近年来，人们越来越担心，对家犬极端面部形态的选择可能会导致眼部疾病的发病率增加。角膜溃疡是家犬常见且痛苦的眼部问题，可导致角膜瘢痕形成和/或穿孔，有可能导致失明。夸张的幼年样颅面形态和大眼睛被怀疑是角膜溃疡的危险因素。本研究旨在量化角膜溃疡风险与形态学因素之间的关系，这些因素包括相对眼睑开口宽度、短头（短口鼻）头骨形状、鼻褶（皱纹）的存在以及眼白暴露情况。对进入一家位于英国的大型小动物转诊医院治疗角膜溃疡和其他无关疾病的犬只进行了为期14个月的横断面研究。如果犬只在医院使用荧光素染料被诊断为角膜溃疡（无论是否因该疾病转诊），或者其病史中有角膜溃疡的既往诊断记录，则被归类为患病。在招募、测量和临床检查的700只犬中，31只患有角膜溃疡。大多数病例为雄性（71%）、小型犬（平均±标准误体重：11.4±1.1千克），最常被诊断出患病的品种是哈巴狗。有鼻褶的犬患角膜溃疡的可能性几乎是没有鼻褶犬的五倍，短头犬（颅面比例<0.5）患角膜溃疡的可能性是非短头犬的二十倍。相对眼睑开口宽度增加10%，溃疡风险增加两倍多。眼白暴露与风险增加近三倍有关。结果表明，人工选择这些面部特征会大大增加角膜溃疡的风险，因此应避免这种选择以改善犬类福利。
