Browsing by Author "Lovely, Colin James"

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    The Nile crocodile of the Okavango Delta in health and disease
    (Stellenbosch : Stellenbosch University, 2007-03) Lovely, Colin James; Leslie, Alison J.; Stellenbosch University. Faculty of Agrisciences. Dept. of Animal Sciences.
    ENGLISH ABSTRACT: Crocodile farming has become an important industry in Southern Africa over the last three decades. The diseases occurring in farmed crocodiles have been well researched, which has contributed to the success of modern crocodile farming operations. However, very little research has been done on diseases in wild crocodiles, and the normal physiology and disease prevalence of wild crocodiles remains largely unknown. In this study Nile crocodiles were captured in the Okavango Delta, Botswana. Blood was collected and normal haematological and blood biochemical ranges were established for a subsample of the population (haematology n=38, biochemistry n=35). The ranges obtained were generally in line with those reported for other species and farmed Nile crocodiles, except for mean haematocrit and total protein, which were relatively low. Parameters were also compared between males and females, as well as between size classes. Females had significantly greater mean red cell cotmt, eosinophils, total protein and potassium than males. Subadults had significantly greater mean haematocrit, haemoglobin, eosinophils, basoph.ils, total protein, globulin, sodium and potassium than yearlings and juveniles. Yearlings had significantly higher blood glucose than juveniles. Cloacal swabs were collected (n=29), which were cultured to establish the normal intestinal flora of these crocodiles. The intestinal flora was found to be diverse, with a mean of 2.7 bacterial species per crocodile. No Salmonella were cultured. Approximately half the crocodiles (48.3 %) also had a fungal component to their intestinal flora. A probiotic was produced based on the normal intestinal flora of the wild crocodiles. The potential for this probiotic to reduce mortalities and improve growth in farmed hatchlings was tested in a controlled experiment. No significant beneficial effect was obtained. A disease survey was carried out on the wild crocodiles by (i) a general clinical examination (n=144), (ii) serological testing for mycoplasmosis (n=30), and (iii) bloodsmear examination for blood parasites (n=38). No clinically apparent sick crocodiles were observed. No antibodies to Mycoplasma crocodyli were detected. The prevalence of hepatozoonosis was 55.3 %. There was no significant difference in the h.aematological parameters of Hepatozooninfected and un-infected crocodiles.