Salivary cortisol is often used as an indicator of stress in canine research; however, other factors contribute to that cortisol level, according to a new study.

Researchers from Monash University in Australia and the University of Pennsylvania conducted a meta-analysis to identify factors that contribute to stress in domestic dogs. The researchers identified a cortisol concentration range and additional factors such as canine characteristics and environmental effects that impact those levels.

The final study, available online, will be published in the October issue of Domestic Animal Endocrinology.

The researchers reviewed databases and conference proceedings from 1992 to 2002 as well as 61 peer-reviewed studies using domestic dog salivary cortisol. Researchers were contacted and 31 raw data sets were shared that represented 5,153 samples from 1,205 dogs.

The researchers identified a cortisol concentration range of 0 to 33.79 μg/dL (mean 0.45 μg/dL, SEM 0.13). They also noted that sex and neuter status, age, living environment and time in that environment before testing, testing environment, owner presence during testing, and collection media all played a part in cortisol levels.

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