Preliminary assessment of the leukocyte coping capacity as a point of care marker in horses with stress associated diseases.

Abstract

BACKGROUND: Stress represents a serious health and welfare concern; however, its objective assessment remains difficult. The equine gastric ulcer syndrome (EGUS) and orthopedic diseases that cause pain are among stress associated diseases in equine medicine. The leukocyte coping capacity (LCC) quantifies oxygen radical generation of neutrophil granulocytes which is altered under stress. Therefore, LCC could be a novel biomarker for stress in horses and we hypothesized that horses with stress associated diseases would have lower LCC values in comparison to horses without these diseases. MATERIALS AND METHODS: In this observational clinical pilot study, 45 privately owned horses were classified according to the most relevant clinical diagnosis based on clinical, laboratory and gastroscopic findings into the following groups: (1) No EGUS; no clinical and/or laboratory and/or gastroscopic signs of EGUS, lameness or other diseases, (2) EGUS; any grade of EGUS, but no clinical and/or laboratory signs of lameness or other diseases, (3) Lameness; any grad of lameness, but no clinical and/or laboratory signs other diseases, any grade of EGUS possible, (4) Other diseases; identified based on abnormal findings in clinical examination and/or laboratory work, with no evidence of lameness, any grade of EGUS possible. The LCC was measured at first visit (T1) and 28 days later (T2) and the values compared among the groups with mean comparison tests and mixed effect models for repeated measures. RESULTS: Primary results indicate that horses in group 3 had significantly (P = 0.012) lower values for LCC compared to horses in the group 1 at T1. Also group 3 horses had highest EGUS scores. At T2 LCC was still significantly lower in this group (P = 0.031), even though the severity of EGUS decreased in all horses with treatment (P = 0.004). CONCLUSION: Lame horses had higher EGUS scores and lower LCC levels, indicating a possible link between lameness, EGUS, and stress. Our findings support further investigation into the use of LCC as a quantitative immunological marker of stress with strong potential for use at point of care.