MTA-ELTE Lendület "Momentum" Companion Animal Research Group, Department of Ethology, Eötvös Loránd University, Budapest, Hungary.
Senior Family Dog Project, Department of Ethology, Eötvös Loránd University, Budapest, Hungary.
Geroscience. 2024 Apr;46(2):1731-1754. doi: 10.1007/s11357-023-00945-9. Epub 2023 Sep 23.
The twofold life expectancy difference between dog breeds predicts differential behavioral and cognitive aging patterns between short- and long-lived dogs. To investigate this prediction, we conducted a cross-sectional analysis using survey data from over 15,000 dogs. We examined the effect of expected lifespan and three related factors (body size, head shape, and purebred status) on the age trajectory of various behavioral characteristics and the prevalence of canine cognitive dysfunction (CCD). Our findings reveal that, although age-related decline in most behavioral characteristics began around 10.5 years of age, the proportion of dogs considered "old" by their owners began to increase uniformly around 6 years of age. From the investigated factors, only body size had a systematic, although not gradual, impact on the aging trajectories of all behavioral characteristics. Dogs weighing over 30 kg exhibited an earlier onset of decline by 2-3 years and a slower rate of decline compared to smaller dogs, probably as a byproduct of their faster age-related physical decline. Larger sized dogs also showed a lower prevalence of CCD risk in their oldest age group, whereas smaller-sized dogs, dolichocephalic breeds, and purebreds had a higher CCD risk prevalence. The identification of differential behavioral and cognitive aging trajectories across dog groups, and the observed associations between body size and the onset, rate, and degree of cognitive decline in dogs have significant translational implications for human aging research, providing valuable insights into the interplay between morphology, physiological ageing, and cognitive decline, and unravelling the trade-off between longevity and relative healthspan.
犬种预期寿命的两倍差异预测了短寿犬和长寿犬之间不同的行为和认知衰老模式。为了验证这一预测，我们使用超过 15000 只犬的调查数据进行了横断面分析。我们检验了预期寿命和三个相关因素（体型、头部形状和纯种身份）对各种行为特征的年龄轨迹和犬认知功能障碍（CCD）患病率的影响。我们的研究结果表明，尽管大多数行为特征的年龄相关性下降始于 10.5 岁左右，但主人认为“老”的犬只比例从 6 岁左右开始均匀增加。在所研究的因素中，只有体型对所有行为特征的衰老轨迹有系统的影响，尽管不是渐进的。体重超过 30 公斤的犬只比体重较小的犬只更早出现 2-3 年的下降，而且下降速度较慢，这可能是其更快的与年龄相关的身体衰退的副产品。较大体型的犬只在最年长的年龄组中也表现出较低的 CCD 风险患病率，而较小体型、长头型品种和纯种犬的 CCD 风险患病率较高。不同犬种之间存在不同的行为和认知衰老轨迹的识别，以及体型与犬认知衰退的发生、速度和程度之间的观察到的关联，对人类衰老研究具有重要的转化意义，为形态、生理衰老和认知衰退之间的相互作用以及长寿和相对健康寿命之间的权衡提供了有价值的见解。
