Comparison of acute versus chronic stress responses to different housing’s systems in cats

Background: The hypothalamic-pituitary-adrenal (HPA) axis and functional systems undergo the assessment of stress levels throughout living environments, contributing to avoid side effects to well-being in domestic animals, including pets. Cortisol represents the most important glucocorticoid found in felis and it is frequently used as standard marker in stress research. The purpose of the present study was to compare the adrenal and haematological patterns of cats, by taking into account the effects of different housing’s systems. The hypothesis was to find a different coping strategies, according to different housings. Materials, Methods & Results: For this study a total of 50 cats were selected on the basis of the breed: European domestic short hair cats, age ranged between 22 and 30 months and housing’s systems, represented by cattery and/or households, respectively. On these basis, cats were distinguished into two groups, represented by group A: 22 cats living in cattery, and group B: 28 cats living in households. Blood samples were collected twice a week, for two consecutive days, during one month and subsequently analysed for haematological analysis and cortisol concentrations. Group B showed higher cortisol concentrations (P < 0.01), Red Blood Cell (P < 0.05), Packed Cell Volume (P < 0.001), Platelets (P < 0.01), Heart Rate and Respiratory Rate (P < 0.05) values, and lower White Blood Cell (P < 0.001) than group A. Discussion: This observational study showed that cats housed in the households group showed higher cortisol, RBC, PCV, Plt, HR and RR values, and lower WBC rather than cattery’s cats. Another point is that males showed higher RBC, PCV, WBC and Plt than females, irrespective of different housing’s systems. The significant lower threshold of cortisol levels in cattery’s cats than household’s cats could suggest that these subjects were probably totally accustomed to cattery’s environment; though these animals were daily stimulated by predictable stimuli and manipulations, characterized by handling and husbandry routine, regular feeding and cleaning times, standard caretaking. On the other hand, the higher cortisol concentrations observed in household’s cats could be due to the different environmental stimuli, characterized by unpredictable handling, modified caretaking, presence of irregular talking, petting and manipulations by owners, which promote probably the expression of species and appropriate behaviour with stimulating activities. The significant highest RBC and PCV values in subjects of group B could be explained on the basis of the more intense activity of these subjects, according to the access to outdoor area. These concomitant higher values were corroborated in the present study by the not surprising positive and significant correlation observed between corresponding RBC and PCV values. The higher PCV values observed in cats of group B could be suggest that their daily frequent activity induced a physiological erythrocytosis, compared to sedentary cattery’s cats. The hypothesis that the home represented more rousing than cattery setting was assessed by the physiological and consistent higher cortisol, RBC, PCV, Plt, HR and RR displayed in the home environment; The only difference between the two groups was that environmental stimulus (chronic stress) was cattery for group A, whereas household for group B. Obtained data indicate that there was a marked benefit in to establish a personnel-cat relationship in addition to the traditionally owner-cat relationship, providing physiological coping strategies in both cattery and home cats; this was corroborate in the present study by the wide but physiological cortisol range. This study indicates that predictability, familiarity and unpredictability are significantly associated with environmental stimuli and with quality of pets’ life.