Validating the use of oral swabs for telomere length assessment in dogs

The relative telomere length, a biomarker of cellular aging, can be influenced by the cumulative effects of positive and negative events experienced by an individual. For this reason, it has been used to assess the welfare of nonhuman species. Ensuring an animal's well-being also involves choosing methodologies that will cause either none or minimal disturbance to the subject; however, no studies using noninvasive sampling for measuring relative telomere length in nonhuman species were found. The present study is the first to investigate alternatives of noninvasive sampling for obtaining dogs’ DNA samples for measuring telomeres. Results showed that different tissue samples from the same individual yield comparable telomere length measurements, validating the use of buccal swabs over dried blood spot from dogs. The development of a noninvasive methodology is paramount for the animal welfare evaluation of captive and wild animals without affecting the subject, while at the same time, allowing a frequent data collection and a continuous monitoring of the well-being state.