Zatroch Katie K, Knight Cameron G, Reimer Julie N, Pang Daniel S J
Cornell University College of Veterinary Medicine, Ithaca, NY, USA.
Veterinary Clinical and Diagnostic Sciences, Faculty of Veterinary Medicine, University of Calgary, 3280 Hospital Dr NW, T2N 4Z6, Alberta, Canada.
BMC Vet Res. 2017 Feb 21;13(1):60. doi: 10.1186/s12917-017-0982-y.
The Canadian Council on Animal Care and American Veterinary Medical Association classify intraperitoneal (IP) pentobarbital as an acceptable euthanasia method in rats. However, national guidelines do not exist for a recommended dose or volume and IP euthanasia has been described as unreliable, with misinjections leading to variable success in ensuring a timely death. The aims of this study were to assess and improve efficacy and consistency of IP euthanasia. In a randomized, blinded study, 51 adult female Sprague-Dawley rats (170-495 g) received one of four treatments: low-dose low-volume (LL) IP pentobarbital (n = 13, 200 mg/kg pentobarbital), low-dose high-volume (LH) IP pentobarbital (n = 14, 200 mg/kg diluted 1:3 with phosphate buffered saline), high-dose high-volume (HH, n = 14, 800 mg/kg pentobarbital), or saline. Times to loss of righting reflex (LORR) and cessation of heartbeat (CHB) were recorded. To identify misinjections, necropsy examinations were performed on all rats. Video recordings of LL and HH groups were analyzed for pain-associated behaviors. Between-group comparisons were performed with 1-way ANOVA and Games-Howell post hoc tests. Variability in CHB was assessed by calculating the coefficient of variation (CV).
The fastest euthanasia method (CHB) was HH (283.7 ± 38.0 s), compared with LL (485.8 ± 140.7 s, p = 0.002) and LH (347.7 ± 72.0 s, p = 0.039). Values for CV were: HH, 13.4%; LH, 20.7%; LL, 29.0%. LORR time was longest in LL (139.5 ± 29.6 s), compared with HH (111.6 ± 19.7 s, p = 0.046) and LH (104.2 ± 19.3 s, p = 0.01). Misinjections occurred in 17.0% (7/41) of euthanasia attempts. Pain-associated behavior incidence ranged from 36% (4/11, LL) to 46% (5/11, HH).
These data illustrate refinement of the IP pentobarbital euthanasia technique. Both dose and volume contribute to speed of death, with a dose of 800 mg/kg (HH) being the most effective method. An increase in volume alone does not significantly reduce variability. The proportion of misinjections was similar to that of previous studies.
加拿大动物保护委员会和美国兽医协会将腹腔内（IP）注射戊巴比妥列为大鼠可接受的安乐死方法。然而，目前尚无关于推荐剂量或体积的国家指南，且IP安乐死被认为不可靠，误注射会导致在确保及时死亡方面成功率不一。本研究的目的是评估并提高IP安乐死的有效性和一致性。在一项随机、双盲研究中，51只成年雌性Sprague-Dawley大鼠（体重170 - 495克）接受以下四种处理之一：低剂量低体积（LL）IP注射戊巴比妥（n = 13，戊巴比妥200毫克/千克）、低剂量高体积（LH）IP注射戊巴比妥（n = 14，200毫克/千克用磷酸盐缓冲盐水按1:3稀释）、高剂量高体积（HH，n = 14，800毫克/千克戊巴比妥）或生理盐水。记录翻正反射消失（LORR）和心跳停止（CHB）的时间。为识别误注射情况，对所有大鼠进行尸检。分析LL组和HH组的视频记录以观察疼痛相关行为。组间比较采用单因素方差分析和Games-Howell事后检验。通过计算变异系数（CV）评估CHB的变异性。
安乐死最快的方法（CHB）是HH组（283.7 ± 38.0秒），相比之下LL组为（485.8 ± 140.7秒，p = 0.002），LH组为（347.7 ± 72.0秒，p = 0.039）。CV值分别为：HH组13.4%；LH组20.7%；LL组29.0%。LL组的LORR时间最长（139.5 ± 29.6秒），相比HH组（111.6 ± 19.7秒，p = 0.046）和LH组（104.2 ± 19.3秒，p = 0.01）。在41次安乐死尝试中有17.0%（7/41）发生误注射。疼痛相关行为发生率在36%（4/11，LL组）至46%（5/11，HH组）之间。
这些数据表明IP戊巴比妥安乐死技术得到了改进。剂量和体积均对死亡速度有影响，800毫克/千克（HH组）的剂量是最有效的方法。仅增加体积并不能显著降低变异性。误注射比例与先前研究相似。
