Psittacine Plasma Concentrations of Elements: Daily Fluctuations and Clinical Implications

Abstract

Abstract. During the past 2 decades, the potential for excessive exposure of pet birds to zinc has become a concern for many pet bird owners. Ideally, avian zinc toxicosis is diagnosed on the basis of history of exposure to zinc, radiographic evidence of ingested metal, occurrence of melena, detection of an elevated plasma zinc concentration, and response to treatment. However, most pet birds suspected of having zinc toxicosis present with vague signs and lack of radiographic evidence; therefore, the diagnosis relies on the presence of an elevated plasma zinc concentration. A question was, is there a significant diurnal variation in the zinc concentration in psittacine birds and could this be clinically relevant? Because studies in other species have shown that zinc is not the only element that shows a diurnal variation, the authors examined 13 other plasma elements including arsenic, cadmium, calcium, cobalt, copper, iodine, iron, magnesium, manganese, molybdenum, potassium, selenium, and total phosphorus. Fifteen adult psittacine birds housed in the same aviary were used in this study. Three blood samples, separated by 4 hours, were taken from the right jugular vein in each bird. All elements were measured in plasma. Zinc, copper, and molybdenum revealed diurnal fluctuations. The results of this study suggest that interpretation of clinical samples may be more complicated than previously believed. Furthermore, on the basis of the results of this study, it is possible that some avian reference ranges may need to be reexamined.

Diagnostic Sampling and Establishing a Minimum Database in Exotic Animal Toxicology

“…Sample hemolysis can also result in artificial increases in serum or plasma zinc concentrations. Second, there is evidence that serum or plasma zinc concentrations show diurnal variation [7]. Thus, interpretation of single, moderately elevated zinc concentrations as evidence for exposure to excessive zinc needs to be done cautiously.…”

Clinical Pathology and Parasitologic Evaluation of Free-Living Nestlings of the Hyacinth Macaw (Anodorhynchus Hyacinthinus)

“…Hematologic and biochemical reference ranges for wild birds are rare, due to the difficulty in obtaining samples from wild animals (Masello and Quillfeldt, 2004). Although data for captive, seized, and captive-reared psittacines are available (Rosenthal et al, 2005;Valle et al, 2008), data on wild psittacines are scarce (Masello and Quillfeldt, 2004;Deem et al, 2005), and no information on free-living Hyacinth Macaws is available. Therefore, we established clinical pathology values and assessed the occurrence of parasitism in Hyacinth Macaw nestlings in their natural environment in the Brazilian Pantanal.…”