Hypovitaminosis A coupled to secondary bacterial infection in beef cattle

Vitamin A is essential for normal growth, development, reproduction, cell proliferation, cell differentiation, immune function and vision. Hypovitaminosis A can lead to a series of pathological damage in animals. This report describes the case of hypovitaminosis A associated with secondary complications in calves. From February to March in 2011, 2-and 3-month old beef calves presented with decreased eyesight, apparent blindness and persistent diarrhea occurred in a cattle farm of Hubei province, China. Based on history inspection and clinical observation, we made a tentative diagnosis of hypovitaminosis A. The disease was confirmed as a congenital vitamin A deficiency by determination of the concentrations of vitamin A in serum and feed samples. Furthermore, pathological and microbiological examination showed that the disease was associated with pathogenic Escherichia coli (E. coli) infection and mucosal barriers damage in intestines. The corresponding treatments were taken immediately, and the disease was finally under control for a month. To our knowledge, this is the first report of hypovitaminosis A coupled to secondary infection of E. coli in beef cattle, advancing our knowledge of how vitamin A affects infection and immunity in animals. This study could also be contributed to scientific diagnosis and treatments of complex hypovitaminosis A in cattle.