Clinical and Pathologic Features of a Suspected Selenium Deficiency in Captive Plains Zebras.

Previous studies have shown that selenium (Se) deficiency is associated with nutritional myopathy, known as white muscle disease (WMD), in horses. However, correlations between Se deficiency and clinical findings, such as hematologic biochemical values and pathological features, have not been evaluated in captive plains zebras. The purpose of the present study was to investigate the clinical and pathologic features that may be caused by a Se deficiency in the captive plains zebra. Clinical findings, feed analyses, hematologic biochemical analyses, response to treatment, and pathologic examination were assessed in six affected plains zebras. The dietary concentration of Se in feed was also tested. Sudden death occurred in two cases during the first day of the onset of symptoms. Two zebras died at 4 days and two zebras survived after treatment. The clinical signs in affected animals were characterized by general weakness, astasia, and abnormal postural positions. The Se concentration in hay from the breeding stable was low, based on the reference value. Glutathione peroxidase (GSH-Px) activity was lower compared with the equine reference value. Multiple areas of subcutaneous steatitis and pale skeletal muscle and myocardium were revealed at gross necropsy. Degeneration and necrosis of myocardial and skeletal muscles, as well as congestion of the liver, lung, and kidney were found via histopathological examination. No suspected bacterial infections were found. Feed analyses, response to treatment, serum GSH-Px activity, and pathological features suggest that Se deficiency may have caused the disease in the six affected captive plains zebra.

[Effects of zinc supplementation on zinc and calcium levels in serum and tissue in burned rats].

OBJECTIVE: To explore the effects of zinc supplementation on zinc and calcium levels in serum and tissue in burned rats. METHODS: Eighty SD rats were randomly divided into C group (control group without scald, n = 8), and N, W, H groups (each consisting of 24 rats), in which the rats were exposed to scalding resulting in partial thickness burns covering 15% of the total body surface area on the back, and then they were fed with diets containing zinc 40 microg/g in N and W groups, and 80 microg/g in H group. A cream containing zinc 761.1 microg/g was applied on the wound in W group at the same time. Eight rats of each group were sacrificed on day 1, 3 and 7 after scald respectively. Venous blood and samples of liver, femur and scald skin were harvested. Zinc and calcium contents in serum and tissues were determined with atomic absorption spectrophotometer. RESULTS: The serum Zn(2+) levels in N, W groups were lower than C group, however, it was obviously higher in H group (up to 16.2 micromol/L) on day 1 after scald. The liver Zn(2+) showed an increasing tendency in all groups, while Ca(2+) level declined in H group, but increased in N, W group. The bone Zn(2+) and Ca(2+) levels showed a progressive declination in all groups from day 1 to 7 after scald. The changes were more obviously in N group than H group (P < 0.05). The Zn(2+) content of the scalded skin increased obviously in H group on first day after scald and in W group on 7th day after scald. The Ca(2+) contents of scalded skin showed marked increases in all groups, especially in N group, but least in W group. CONCLUSION: There are obvious changes in Zn(2+) and Ca(2+) contents of serum and tissues after scald injury and zinc supplementation. The effects of zinc supplementation on calcium level in the tissue need to be further studied.