Development and application of biochemical and haematological reference intervals to identify unhealthy green sea turtles (Chelonia mydas)

Biochemical and haematological reference intervals (RIs) have been reported for sea turtles, but their value for ante-mortem disease diagnosis may be limited due to small sample sizes and outdated statistical analyses. In the present study, 290 green sea turtles (Chelonia mydas) were captured, clinically assessed and blood sampled. Of these, 211 were classified as ‘clinically healthy’ and 25 as ‘clinically unhealthy’. RIs were estimated using data from the healthy turtles and compared with blood values from the unhealthy animals.All of the unhealthy animals had plasma biochemical and haematological values outside one or more RIs (albumin, 48% of unhealthy animals; alkaline phosphatase, 35%; aspartate transaminase, 13%; creatinine, 30%; globulin, 3%; glucose, 34%; lactic dehydrogenase, 26%; phosphorus, 22%; sodium, 13%; thrombocytes, 57%; and monocytes, 5%). Among small immature turtles, those with Chelonibia testudinaria plastron barnacle counts ⩾20 were three times more likely to be unhealthy than those with no barnacles. In addition, small immature and mature turtles were more likely to be unhealthy than large immature turtles.