Saliva sampling in dogs: How to select the most appropriate procedure for your study

Saliva sampling is an easy, noninvasive method to assess short-term physiological changes, and as such is a valuable addition to behavioral studies in dogs. Different methods for collecting saliva samples in dogs have been reported in literature, and there appears to be no "standard operating procedure" that suits the needs of all studies. Hence, this review provides a clear overview of "considerations" to take into account when selecting the most appropriate saliva sampling procedure. Different collection devices, procedures, and practical considerations are discussed in light of available literature and the authors' practical experience, to guide researchers in this selection process. Additional factors that might influence the (interpretation of the) results are also discussed, so that these can be taken into account for optimization of the research protocol. This guidance should facilitate the initial selection of the most appropriate procedure, but each researcher is strongly recommended to conduct preliminary tests to detect and prevent possible biases or practical issues beforehand. Standardization is key to obtain reliable results that can be compared to other studies.