狗的性腺切除术与各种非传染性健康状况的风险变化有关,但很少有研究检查其对传染病结局的影响。我们研究的目的是估计性腺切除术对巴贝西虫病诊断的发病率的因果影响,以及在确诊病例中患严重巴贝西虫病的风险,从2013年到2020年,在南非一家兽医学院医院看到的6个月及以上的狗。评估性腺切除术对犬巴贝西虫病诊断发生率的影响。我们进行了一项病例对照研究,通过医院的初级保健服务观察到的狗的发病率密度抽样,适应性,年龄,品种类别和体重。我们确定了811例病例,并选择了3244个时间匹配的对照。为了评估性腺切除术对babesiosis犬疾病严重程度的影响,我们在所有诊断为巴贝斯虫病的狗中进行了一项回顾性队列研究(n=923),包括这811例病例和另外112例转诊到医院,也适应性,年龄,品种类别和体重。性腺切除术大大降低了诊断犬的巴贝斯病的发生率(总效应发生率比[IRR]0.5;95%置信区间[CI]0.41-0.60)和严重巴贝斯病的风险(总效应风险比[RR]0.72;95%CI0.60-0.86)。临界点敏感性分析表明,这些效应估计对未测量的混杂偏差是稳健的。没有证据表明按性别改变性腺切除术的效果,对于两种结果,男性和女性的效果估计在质量上相似。与女性相比,男性巴贝西虫病的发病率较高(IRR1.74;95%CI1.49-2.04),严重疾病的风险较高(RR1.12;95%CI0.98-1.28).总之,我们的研究表明,性腺切除术对6个月及以上的雄性和雌性犬的发病率和严重程度具有强大的保护作用,并为该人群中对狗进行性腺切除术的总体风险和益处的辩论提供了重要证据。
Gonadectomy in dogs is associated with changes in risks of a variety of non-infectious health conditions, but few studies have examined its effects on infectious disease outcomes. The objectives of our
study were to estimate the causal effect of gonadectomy on the incidence rate of
babesiosis diagnosis, and on the risk of severe
babesiosis in diagnosed cases, in dogs 6 months and older seen at a veterinary academic hospital in South Africa from 2013 through 2020. To estimate the effect of gonadectomy on the incidence rate of babesiosis diagnosis in dogs, we conducted a case-control
study with incidence density sampling of dogs seen through the hospital\'s primary care service, adjusting for sex, age, breed category and weight. We identified 811 cases and selected 3244 time-matched controls. To estimate the effect of gonadectomy on disease severity in dogs with babesiosis, we conducted a retrospective cohort
study among all dogs with a diagnosis of
babesiosis (n=923), including these 811 cases and a further 112 referred to the hospital, also adjusting for sex, age, breed category and weight. Gonadectomy substantially reduced the incidence rate of babesiosis (total effect incidence rate ratio [IRR] 0.5; 95 % confidence interval [CI] 0.41-0.60) and the risk of severe babesiosis among diagnosed dogs (total effect risk ratio [RR] 0.72; 95 % CI 0.60-0.86). Tipping point sensitivity analysis shows that these effect estimates are robust to unmeasured confounding bias. There was no evidence for modification of the effect of gonadectomy by sex, with effect estimates qualitatively similar for males and females for both outcomes. Compared to females, males had a higher incidence rate of babesiosis (IRR 1.74; 95 % CI 1.49-2.04) and a higher risk of severe disease (RR 1.12; 95 % CI 0.98-1.28). In conclusion, our
study shows a robust protective effect of gonadectomy on the incidence and severity of babesiosis in both male and female dogs 6 months of age and older, and contributes important evidence to the debate on the overall risks and benefits of gonadectomy to dogs in this population.