Centre for Feline Nutrition, School of Agriculture and Environment, College of Science, Massey University, Private Bag 11-222, Palmerston North, 4442, New Zealand.
Zoology and Ecology Group, School of Natural Sciences, Massey University, Private Bag 11-222, Palmerston North, 4442, New Zealand.
Theriogenology. 2022 Feb;179:237-244. doi: 10.1016/j.theriogenology.2021.12.005. Epub 2021 Dec 6.
Accurate and reliable monitoring of ovarian activity is challenging in many felids as current methods are either invasive or not amenable to real-time assessments. This 45-day study assessed whether accelerometry and infrared (IR) thermography can be used to address these limitations. Intact female domestic cats (n = 12) were given 0.088 mg kg day altrenogest (progestin) orally for 37 days to suppress follicular growth. On Day 40, cats were given 75 IU eCG im to induce follicular growth and 50 IU hCG im 80 h later to induce ovulation. Cats were ovariohysterectomised 30-31 h after the hCG treatment. Actical® accelerometers were fitted to the cats' collars and activity monitored continuously from the start of the altrenogest treatment until ovariohysterectomy. Infrared images of the perivulvar, perianal, and gluteal area were taken of each cat on Day 30 and daily from Days 36-45 of the study. Perivulvar temperature (PVT), PVT relative to gluteal temperatures (PVT-GT), and PVT relative to perianal temperature (PVT-PAT) were recorded for each image. Blood samples were collected on Days 0, 10, 30, and 40, immediately prior to the hCG treatment, and at the time of ovariohysterectomy. Serum oestradiol and progesterone concentrations indicated complete ovarian suppression by Day 30 and, together with morphological assessment of the ovaries, confirmed the induction of follicular growth and ovulation in all cats. Daily activity counts differed among cats (P < 0.001), so the daily activity counts of each cat were converted to a proportional change from the average daily activity count from Days 30-39 (defined as the 'proportional daily activity'). Proportional daily activity counts increased after the stimulation of follicular growth with eCG, with peak levels (2.03 ± 0.29-fold higher than pre-treatment levels; P = 0.006) occurring three days after the eCG treatment. The PVT-GT showed the greatest sensitivity to detect subtle changes in body temperature, increasing from early to late follicular growth (1.96 ± 0.33 °C increase from Day 41-43; P < 0.001) and decreasing after hCG-induced ovulation (1.24 ± 0.41 °C decrease from Day 43-45; P = 0.01). In conclusion, both accelerometry and IR thermography show potential as non-invasive, real-time methods for assessing ovarian activity in cats, but further research is required to determine if these methods could be used to monitor natural/non-stimulated oestrous cycles.
准确可靠地监测卵巢活动在许多猫科动物中具有挑战性，因为目前的方法要么具有侵入性，要么不适用于实时评估。本为期 45 天的研究评估了加速度计和红外（IR）热成像是否可用于解决这些局限性。给 12 只未去势的雌性家猫口服 0.088mgkg 天的阿尔特罗内戈斯特（孕激素），持续 37 天以抑制卵泡生长。第 40 天，给猫肌内注射 75IU eCG 以诱导卵泡生长，并在 80 小时后肌内注射 50IU hCG 以诱导排卵。hCG 治疗后 30-31 小时对猫进行卵巢子宫切除术。从开始接受阿尔特罗内戈斯特治疗到卵巢子宫切除术，将 Actical®加速度计安装在猫的项圈上，连续监测活动。在第 30 天和研究的第 36-45 天每天对每只猫进行外阴、肛周和臀区的红外图像拍摄。记录每个图像的外阴温度（PVT）、PVT 与臀温（PVT-GT）的比值和 PVT 与肛周温度（PVT-PAT）的比值。在第 0、10、30 和 40 天收集血液样本，在 hCG 治疗前和卵巢子宫切除术时进行。血清雌二醇和孕酮浓度表明第 30 天完全抑制卵巢功能，结合卵巢的形态学评估，证实所有猫均诱导卵泡生长和排卵。猫之间的每日活动计数存在差异（P<0.001），因此将每只猫的每日活动计数转换为从第 30-39 天的平均每日活动计数的比例变化（定义为“比例日活动”）。在 eCG 刺激卵泡生长后，比例日活动计数增加，在 eCG 治疗后三天达到峰值（比治疗前高 2.03±0.29 倍；P=0.006）。PVT-GT 对检测体温的细微变化最敏感，在外周卵泡生长早期到晚期（从第 41-43 天增加 1.96±0.33°C；P<0.001）增加，在 hCG 诱导排卵后（从第 43-45 天减少 1.24±0.41°C；P=0.01）减少。总之，加速度计和红外热成像都显示出作为评估猫卵巢活动的非侵入性、实时方法的潜力，但需要进一步研究以确定这些方法是否可用于监测自然/非刺激性发情周期。
