Should stress management be part of the clinical care provided to chronically ill dogs?

As a consequence of their physical and/or psychological effects, on-going diseases may have the potential to induce chronic stress in dogs. Chronic stress may contribute to disease progression and negatively affect welfare. By investigating whether on-going illnesses cause chronic stress in dogs and exploring the relationship between hair cortisol and potential disease-dependent and disease-independent stressors, this research aimed to determine if stress management should be integrated into veterinary care. Hair samples were collected from 33 dogs to assess cortisol levels (ill n = 16, 12 nonblack and 4 black; healthy n = 17, 12 nonblack and 5 black) using a commercially available biochemical assay. In addition, a questionnaire was distributed to the owners of these dogs to gather information on pet care, chronic stress behaviors and disease characteristics. The hair cortisol levels of black and nonblack dogs did not differ significantly (U = 89, df = 31, P = 0.442). Data were therefore pooled for further analysis. Significant differences were not found in the hair cortisol levels of chronically ill compared to healthy dogs (t = −0.655, df = 30, P = 0.517), or the number of dogs with chronic stress behaviors in each group (χ2 = 0.667, df = 1, P = 0.414). Ill dogs with disease signs or lifestyle restrictions did not have significantly different hair cortisol levels to those without them (signs: t = 0.321, df = 14, P = 0.753; lifestyle restrictions: t = 0.154, df = 14, P = 0.880). Hair cortisol was not significantly related to the number of veterinary visits (rs = −0.152, df = 31, P = 0.397). However, it was significantly correlated with the length of time regularly left alone in healthy and chronically ill dogs (rs = 0.417, df = 31, P = 0.016). In addition, the hair cortisol levels of healthy dogs were significantly correlated with time regularly left alone in single dog (rs = 0.726, df = 7, P = 0.027) but not multidog households (rs = 0.528, df = 6, P = 0.179). Further research with a larger sample size is required to confirm our findings. Nonetheless, as chronic stress may be detrimental to the health of dogs, lifestyle factors, such as the social environment and time regularly left alone, should be taken into consideration when planning canine veterinary care.