Department of Animal Health and Antimicrobial Strategies, National Veterinary Institute, 751 89, Uppsala, Sweden.
Department of Clinical Sciences, Faculty of Veterinary Medicine and Animal Science, Swedish University of Agricultural Sciences, 750 07, Uppsala, Sweden.
Acta Vet Scand. 2023 Jul 12;65(1):34. doi: 10.1186/s13028-023-00694-x.
The effects of climate change, loss of pastureland to other land usage and presence of large carnivores are the main reasons for the increase in supplementary feeding of semi-domesticated reindeer (Rangifer tarandus tarandus) in Fennoscandia over the last decades. Feeding might expose reindeer to stress and increased animal-to-animal contact, leading to an increased risk of infectious disease transmission, such as infectious keratoconjunctivitis (IKC). As it can develop rapidly and be very painful, IKC is described as an important animal welfare concern and a potential source of economic loss. The aim of this study was to investigate the current presence of IKC and potential associations between IKC and supplementary feeding through an online questionnaire survey, distributed among reindeer herders in Norway and Sweden in 2021.
Seventy-six reindeer herders (33 from Norway and 43 from Sweden) responded to the questionnaire, representing 6% and 4% of the registered reindeer herding groups in Norway and Sweden, respectively. Infectious keratoconjunctivitis was common, with 54 (71%) of the 76 herders that responded having observed clinical signs during the past 10 years. These signs were mainly observed as increased lacrimation, causing "wet cheeks", but also as keratitis and conjunctivitis. Autumn and winter were the seasons in which IKC was observed most. The herders reported several measures, such as slaughter and isolation of affected reindeer, to counteract the spread of disease. The herding year 2019/2020 was associated with reports of outbreaks of IKC in herds as well as being the herding year where most herders (80%) had performed supplementary feeding. A significant association was found between IKC and feeding performed in an enclosure (odds ratio = 15.20), while feeding on free-range areas had a non-significant, negative, relationship with the appearance of IKC outbreaks (odds ratio = 0.29). Finally, there was a trend in the data suggesting that IKC affected calves especially.
Infectious keratoconjunctivitis is a common disease, mainly observed in winter and autumn. It usually has mild to moderately severe clinical signs. Our results imply that IKC is associated with stress and feeding situations and that calves might be more susceptible than adults, however, this needs to be confirmed with further studies, preferably at an individual animal level.
气候变化、牧场向其他用途的转变以及大型食肉动物的存在，是过去几十年间芬诺斯堪的亚（Fennoscandia）地区对半驯化驯鹿（Rangifer tarandus tarandus）进行额外补饲的主要原因。补饲可能会使驯鹿面临压力，增加动物之间的接触，从而增加传染病传播的风险，例如传染性角膜结膜炎（IKC）。由于该病可能迅速发展且非常疼痛，因此被认为是一个重要的动物福利问题，也是经济损失的潜在来源。本研究旨在通过 2021 年在挪威和瑞典的驯鹿牧民中进行的在线问卷调查，调查当前 IKC 的流行情况以及 IKC 与补饲之间的潜在关联。
共有 76 名驯鹿牧民（33 名来自挪威，43 名来自瑞典）回答了问卷，分别占挪威和瑞典注册驯鹿牧民群体的 6%和 4%。ICK 很常见，76 名回答者中有 54 名（71%）在过去 10 年中观察到了临床症状。这些症状主要表现为流泪增加，导致“湿脸颊”，但也表现为角膜炎和结膜炎。秋季和冬季是观察到 IKC 最多的季节。牧民们报告了几种措施，例如扑杀和隔离受感染的驯鹿，以阻止疾病传播。2019/2020 放牧年与牧民群体中 IKC 爆发的报告以及大多数牧民（80%）进行额外补饲的放牧年有关。ICK 与围栏补饲之间存在显著关联（优势比=15.20），而在自由放养区补饲与 IKC 爆发的出现呈非显著负相关（优势比=0.29）。最后，数据显示出一种趋势，表明 IKC 尤其会影响幼鹿。
传染性角膜结膜炎是一种常见疾病，主要发生在冬季和秋季。它通常具有轻度至中度严重的临床症状。我们的结果表明，ICK 与应激和补饲情况有关，幼鹿可能比成年鹿更容易感染，但这需要进一步研究来证实，最好在个体动物水平上进行。
