TLDR Black hair in cats has higher cortisol levels than white hair.
This study on 27 domestic cats examined the impact of coat color on hair cortisol concentration (HCC), revealing that black hair had significantly higher cortisol levels than white hair, while no significant difference was found between ginger and white hair. A positive correlation was also observed between HCC and behavioral issues like attacking handlers and excessive vocalization. The findings suggest that hair color should be considered in cortisol studies and that behavioral issues may be linked to higher stress levels in cats. The study emphasizes the need for larger studies and the development of reference values for different hair colors to enhance stress measurement accuracy in animals.
296 citations
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October 2018 in “General and Comparative Endocrinology” Hair cortisol is a reliable way to measure long-term stress in animals.
23 citations
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August 2017 in “Scientific Reports” 69 citations
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May 2016 in “General and Comparative Endocrinology” External factors can significantly affect hair cortisol levels, so it's not always a reliable stress marker.
118 citations
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October 2014 in “Journal of Dairy Science” Tail switch hair is best for measuring cortisol in Holstein cows, with white hair and multiparous cows showing higher levels.
199 citations
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July 2007 in “General and Comparative Endocrinology” Hair cortisol can reliably indicate chronic stress in cats and dogs.
September 2025 in “International Journal of Molecular Sciences” Hair analysis could help diagnose and treat schizophrenia more effectively.
September 2025 in “Cosmoderma” Pandemic stress worsens hair loss and skin issues, suggesting combined mental and skin care treatments.
3 citations
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November 2021 in “Stress” Girls had higher stress hormone levels during school due to social and emotional issues, while boys had higher overall hormone levels with slight changes when school started.
9 citations
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February 2020 in “Stress” Children with lower inhibitory control experience more stress when starting third grade.
8 citations
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October 2020 in “Infant behavior & development” Collecting hair for cortisol analysis is possible in low-income mother-toddler pairs.