Hematology and serum biochemistry values of trapped, healthy, free-ranging rock hyraxes (Procavia capensis) and their association with age, sex, and gestational status

Background: The rock hyrax (Procavia capensis) is an herbivore prevalent from South Africa to Turkey, and a most common zoo animal. Although many studies of hyrax diseases and physiology are available, chnicopathologic data are limited. Objectives: The purpose of this study was to establish comprehensive hematologic and biochemical reference intervals for trapped, apparently healthy, free-ranging rock hyraxes using modern laboratory methods and to assess differences related to sex, gestation, and age. Methods: Blood samples were obtained from 27 healthy, free-ranging hyraxes under anesthesia. Gender, body weight, and gestational status were recorded. Hematologic (n = 25) and serum biochemical (n = 22) analyses were performed using standard automated methodology. Data for male vs female, adult vs juvenile, and pregnant vs nonpregnant female hyraxes were compared using the Mann-Whitney U-test. Associations between variables were assessed using Pearson's or Spearman rank correlation tests. Results: Significant age- and sex-related, but not gestation-related differences were observed in several variables. Serum alkaline phosphatase activity and phosphorus concentration were significantly higher in juveniles compared with adults. A unique type of monocyte comprised 1-3% of leukocytes in 4 hyraxes. Markedly high serum creatine kinase (CK) activity was observed in most hyraxes. Conclusions: The large number of animals and the availability of sex, age, and gestational data in this study will be useful to zoo and wildlife veterinarians working with rock hyraxes. High serum concentrations of betahydroxybutyric acid in the rock hyrax, compared with dogs, cats, and ruminants, may be related to its unique digestive system. High CK activity may have been the result of a capture myopathy-like syndrome. The unique monocytes in hyraxes resemble those of elephants and are a novel finding in this species.