Fred Reyers

CYSTINE UROLITHIASIS IN A CARACAL (CARACAL CARACAL)

In July 2009, a 14-yr-old male caracal (Caracal caracal) at the National Zoological Gardens of South Africa was found, on abdominal ultrasound, to have a single large cystolith. The cystolith was removed, and the composition was determined to be 100% cystine. Blood and urine samples were also collected from three other apparently healthy caracals at the zoo and were submitted, together with the samples from the affected animal, for analysis using gas chromatograph mass spectrometry for cystine, lysine, alanine, and ornithine levels. The cystine levels in the urine, the fractional excretion of cystine, and the normalized excretion of cystine (micromol/g of creatinine) were all higher in the affected caracal than in the healthy animals. Only a single other case of cystine urolithiasis has been previously reported in any wild felid in the literature.

Comparative serum fatty acid profiles of captive and free-ranging cheetahs (Acinonyx jubatus) in Namibia

Cheetahs (Acinonyx jubatus) are highly specialised large felids, currently listed as vulnerable on the IUCN red data list. In captivity, they are known to suffer from a range of chronic non-infectious diseases. Although low heterozygosity and the stress of captivity have been suggested as possible causal factors, recent studies have started to focus on the contribution of potential dietary factors in the pathogenesis of these diseases. Fatty acids are an important component of the diet, not only providing a source of metabolisable energy, but serving other important functions in hormone production, cellular signalling as well as providing structural components in biological membranes. To develop a better understanding of lipid metabolism in cheetahs, we compared the total serum fatty acid profiles of 35 captive cheetahs to those of 43 free-ranging individuals in Namibia using gas chromatography-mass spectrometry. The unsaturated fatty acid concentrations differed most remarkably between the groups, with all of the polyunsaturated and monounsaturated fatty acids, except arachidonic acid and hypogeic acid, detected at significantly lower concentrations in the serum of the free-ranging animals. The influence of age and sex on the individual fatty acid concentrations was less notable. This study represents the first evaluation of the serum fatty acids of free-ranging cheetahs, providing critical information on the normal fatty acid profiles of free-living, healthy individuals of this species. The results raise several important questions about the potential impact of dietary fatty acid composition on the health of cheetahs in captivity.

SUBCUTANEOUS XANTHOMATOSIS IN A GREAT WHITE PELICAN (PELECANUS ONOCROTALUS)

Abstract: A great white pelican (Pelecanus onocrotalus) was referred for assessment of a subacute-onset, nonpainful swelling located in the pectoral region. Physical examination revealed a firm, round, well-circumscribed subcutaneous mass approximately 10 cm in diameter. Cytological evaluation of a fine needle aspirate of the mass was consistent with a mesenchymal tumor. The mass was excised, and a diagnosis of xanthomatosis was made based on histopathologic results. Avian xanthomatosis is a nonneoplastic condition of unknown etiology. Possible causes of this condition include trauma, metabolic or nutritional disorders. Similar lesions were not observed in the nine conspecifics that were fed the same diet and housed in the same enclosure. To our knowledge, this is the first report of xanthomatosis in the family Pelecanidae.