Abstract: 【Objective】 This study was conducted to investigate the relationship between hoof disease and blood indicators and intestinal microbiota composition.【Method】 According to clinical examination,6 British thoroughbred mares aged (12±3) years old with hoof disease were selected as the experimental group (group S),and 6 healthy British thoroughbred mares with similar weight and age were selected as the control group (group C).Clinical examination and evaluation were performed for 3 days.The cervical venous blood and rectal feces of the two groups were collected,and blood routine and blood biochemical examination were performed.16S rRNA sequencing was used to detect the composition of intestinal flora in horses.【Result】 Clinical examination showed that horses in group S had lameness,hoof nail deformation and other symptoms.Blood routine test showed that there were no significant differences in blood indexes between the two groups (P＞0.05), among which the leukocyte count and neutrophil count in the blood of group S were higher than the normal range, and the hemoglobin concentration was lower than the normal range.Blood biochemical tests showed that compared with group C,the contents of triglyceride,total protein,urea,creatinine in group S showed an upward trend,while the contents of albumin,serum total bilirubin and other indicators showed a downward trend (P>0.05).16S rRNA sequencing results showed that at the phylum level,compared with group C,the relative abundance of Elusimicrobia in group S was significantly decreased (P＜0.05),and relative abundance of SR1 was extremely significantly decreased (P＜0.01).At the genus level,compared with group C,the relative abundance of Weissella,Pedomicrobium,Pontibacter and Kurthia in group S was significantly increased (P＜0.05),and the relative abundance of Escherichia,Candidatus_Endomicrobium,Microvirga,Peptococcus and Prevotella were significantly decreased (P＜0.05).There were 10 bacteria with significant difference in intestinal flora between the two groups. 【Conclusion】 After the occurrence of hoof disease,there would be inflammation in the body,resulting in damage to liver and kidney function,changes in the abundance of intestinal flora,and reduced digestive capacity.The results laid a foundation for further exploration of the relationship between intestinal flora and metabolic disorders and hoof disease,and provided clues for the prevention and treatment of hoof disease by regulating intestinal flora.

Key words: British thoroughbred horses; hoof disease; blood indexes; intestinal flora