Leister Ellie, Morton John, Atwell Rick, Webster Rob
1 Pet Intensive Care Unit, Veterinary Specialist Services and Animal Emergency Service, Underwood, Australia.
2 Jemora Pty, Geelong, Australia.
J Feline Med Surg. 2018 Jun;20(6):465-478. doi: 10.1177/1098612X17733628. Epub 2017 Oct 10.
Objectives The objective of this study was to describe seasonality, demographics, presentations, treatments, complications and outcomes for cats with Ixodes holocyclus causing tick paralysis, and to identify risk factors for mortality. Methods This was a retrospective single cohort study with 2077 cases occurring between 2008 and 2016, and presenting to one of four emergency clinics in south-eastern Queensland, Australia. Case mortality at 5 days post-presentation could be determined for 1742 cases, and potential risk factors for mortality were assessed using random-effects logistic regression. Results Cases occurred all year round, but there was a marked seasonal pattern with more cases presenting in spring than any other season. Overall, 54/1742 cases (3%) died by 5 days after presentation. Five day mortality incidence for cases that received polyclonal canine tick antitoxin serum (TAS) and recommended treatment was 28/1410 (2%) vs 4/52 (8%) for cases that did not receive TAS ( P <0.001). Mechanical ventilation was recommended for 131/2077 cases (6%). Where mechanical ventilation was recommended but not implemented, mortality incidence was 15/17 (88%), whereas 4/22 cases (18%) that received mechanical ventilation died by day 5. From multivariable analyses, initial gait score (overall P = 0.047) and body temperature on presentation (overall P <0.001) were independently associated with mortality; cases with higher gait scores and those with body temperatures <35°C were at greater risk of death. Cases that had an adverse reaction to TAS were also more likely to die ( P = 0.002). Additional ticks were detected at coat clipping for 80/872 (9%) the cases that were clipped, and coat clipping was associated with a reduced risk of mortality ( P = 0.020). Risk of mortality did not differ significantly by time of year, clinic location, breed, sex, neuter status, age, weight, coat length or number of ticks found. Conclusions and relevance The overall mortality risk for cats treated for tick paralysis caused by I holocyclus is low. Risk factors for mortality include advanced gait and respiratory scores, and hypothermia at presentation. Coat clipping and TAS reduce the risk of mortality, whereas the occurrence of a TAS reaction increases the risk. Mechanical ventilation reduces mortality risk in cats with respiratory failure due to tick paralysis.
目的 本研究的目的是描述感染全环硬蜱导致蜱瘫痪的猫的季节性、人口统计学特征、临床表现、治疗方法、并发症及预后，并确定死亡的危险因素。方法 这是一项回顾性单队列研究，纳入了2008年至2016年间在澳大利亚昆士兰州东南部的四家急诊诊所之一就诊的2077例病例。可确定1742例病例就诊后5天的病死率，并使用随机效应逻辑回归评估死亡的潜在危险因素。结果 病例全年均有发生，但存在明显的季节性模式，春季就诊的病例多于其他任何季节。总体而言，1742例病例中有54例（3%）在就诊后5天内死亡。接受多克隆犬蜱抗毒素血清（TAS）及推荐治疗的病例5天病死率为28/1410（2%），未接受TAS的病例为4/52（8%）（P<0.001）。2077例病例中有131例（6%）建议进行机械通气。在建议进行机械通气但未实施的病例中，病死率为15/17（88%），而接受机械通气的22例病例中有4例（18%）在第5天死亡。多变量分析显示，初始步态评分（总体P=0.047）和就诊时体温（总体P<0.001）与死亡独立相关；步态评分较高及体温<35°C的病例死亡风险更高。对TAS有不良反应的病例也更可能死亡（P=0.002）。在872例接受剪毛的病例中有80例（9%）在剪毛时发现额外的蜱，剪毛与降低死亡风险相关（P=0.020）。死亡风险在一年中的不同时间、诊所位置、品种、性别、绝育状态、年龄、体重、被毛长度或发现的蜱数量方面无显著差异。结论及意义 因全环硬蜱导致蜱瘫痪而接受治疗的猫的总体死亡风险较低。死亡的危险因素包括晚期步态和呼吸评分以及就诊时体温过低。剪毛和TAS可降低死亡风险，而TAS反应的发生会增加风险。机械通气可降低因蜱瘫痪导致呼吸衰竭的猫的死亡风险。
