Comparison of Cortisol Concentrations in Different Matrices in Alpine Ibex (Capra ibex) at the Zoo

SIMPLE SUMMARY: Zoos help to rescue, rehabilitate, and care for wildlife. Approximately fifteen years ago, the Alpine ibex (Capra ibex) was successfully reintroduced into the Alps. There are at least 17 zoos throughout Europe that keep Alpine ibexes in captivity. To ensure success, the staff must understand the animal’s specific requirements and provide leading managers and researchers to investigate strategies such as feed quality control, successful reproduction, and appropriate social group structure. The animal welfare strategy is an important factor for success. Appropriate and stress-free animal capture and sampling methods are especially important. Non-invasive sampling methods are increasingly being used in veterinary practice. Cortisol (C) concentrations can be measured in various matrices, such as saliva, hair, and faeces. Blood collection using venipuncture, which is stressful, can be replaced by collection with kissing bugs (Triatomines) or medicinal leeches (Hirudo medicinalis). In this article, C concentrations in different matrices were compared in Alpine ibexes at the zoo. Differences according to the sex, age, and season of sampling were also compared. ABSTRACT: The usefulness of blood collection using venipuncture versus kissing bugs or medicinal leeches and the collection of saliva, faeces, hair, urine, and tears for measuring “immunoreactive” C (iC) concentration in Alpine ibexes was verified using commercial enzyme immunoassays. The mean value of serum C was highest in serum collected using venipuncture and lowest in serums collected using kissing bugs. Statistically significant differences were observed between venipuncture and kissing bugs and between leeches and kissing bugs. However, no statistically significant difference was found in C concentrations between samples collected with venipuncture and those collected with leeches. The highest mean value of C concentration was measured in serum (all three methods), followed by that in hair and faeces, and the lowest mean value was found in saliva. Statistically significant differences were found between saliva and faeces samples and between saliva and hair samples. The difference between the concentrations for faeces and hair was not statistically significant. A significant difference in C concentration between males and females was found in saliva. A significant difference in C concentration among different ages was measured in serum obtained using venipuncture in all three groups and in faeces between the groups older than ten years and younger than 10 months. Highly significant differences in C concentrations were also found between hair sampled in summer and hair sampled in autumn. Collecting tear and urine samples is a laborious procedure and is therefore less acceptable for C determination. Due to the small number of samples, statistical values are not given for these two matrices.