Neary J M, Booker C W, Wildman B K, Morley P S
Department of Animal and Food Sciences, Texas Tech University, Lubbock, TX.
Feedlot Health Management Services Ltd, Okotoks, AB, Canada.
J Vet Intern Med. 2016 Jan-Feb;30(1):326-34. doi: 10.1111/jvim.13789. Epub 2015 Nov 8.
Anecdotal reports suggest the incidence of right-sided congestive heart failure (RHF) in feedlot cattle is increasing; however, the rate of occurrence and risk factors are largely unknown.
The purposes of this study were to evaluate the risk of RHF over time and among feedlots, to characterize some of the risk factors for RHF, and to investigate how risk factors may affect the timing of RHF occurrence.
The population at risk consisted of 1.56 million cattle that were placed in 10 Canadian feedlots during the years 2000, 2004, 2008, and 2012, and 5 US feedlots during the year 2012.
A retrospective observational study was conducted. Variables, including year of feedlot entry, were evaluated for association with RHF using zero-inflated negative binomial and logistic regression models. Factors affecting time to RHF were evaluated using Cox proportional hazard regression analyzes. Death from digestive disorders (DD) served as a control.
The risk of RHF in Canadian feedlots doubled from the year 2000 to the year 2012 (P = .003). For every 10,000 cattle entering US feedlots in 2012, 11 cattle died from RHF and 45 cattle died from DD. The median time to RHF was 19 weeks. Cattle treated for bovine respiratory disease were 3 times more likely to die from RHF, and they died earlier in the feeding period.
A doubling of the incidence of RHF over a short time period is concerning, particularly for US feedlots situated at moderate altitudes in the High Plains.
轶事报道表明，饲养场肉牛右侧充血性心力衰竭（RHF）的发病率正在上升；然而，其发生率和风险因素在很大程度上尚不清楚。
本研究的目的是评估一段时间内以及不同饲养场中RHF的风险，确定RHF的一些风险因素，并研究风险因素如何影响RHF发生的时间。
风险群体包括2000年、2004年、2008年和2012年安置在加拿大10个饲养场的156万头牛，以及2012年安置在美国5个饲养场的牛。
进行了一项回顾性观察研究。使用零膨胀负二项式和逻辑回归模型评估包括进入饲养场年份在内的变量与RHF的关联。使用Cox比例风险回归分析评估影响发生RHF时间的因素。以死于消化系统疾病（DD）作为对照。
从2000年到2012年，加拿大饲养场中RHF的风险增加了一倍（P = 0.003）。2012年，每10000头进入美国饲养场的牛中，有11头牛死于RHF，45头牛死于DD。发生RHF的中位时间为19周。接受过牛呼吸道疾病治疗的牛死于RHF的可能性高出3倍，并且在育肥期较早死亡。
在短时间内RHF发病率增加一倍令人担忧，特别是对于位于高平原中等海拔地区的美国饲养场。
