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Case Description: 3 hornbills (2 Papua hornbills [Aceros plicatus] and 1 longtailed hornbill [Tockus albocristatus]) were evaluated because of general listlessness and loss of feather glossiness., Clinical Findings: Because hepatic iron storage disease was suspected, liver biopsy was performed and formalin-fixed liver samples were submitted for histologic examination and quantitative image analysis (QIA). Additional frozen liver samples were submitted for chemical analysis. Birds also underwent magnetic resonance imaging (MRI) under general anesthesia for noninvasive measurement of liver iron content. Serum biochemical analysis and analysis of feed were also performed. Results of diagnostic testing indicated that all 3 hornbills were affected with hepatic iron storage disease., Treatment and Outcome: The iron chelator deferiprone was administered (75 mg/kg [34.1 mg/lb], PO, once daily for 90 days). During the treatment period, liver biopsy samples were obtained at regular intervals for QIA and chemical analysis of the liver iron content and follow-up MRI was performed. In all 3 hornbills, a rapid and large decrease in liver iron content was observed. All 3 methods for quantifying the liver iron content were able to verify the decrease in liver iron content., Clinical Relevance: Orally administered deferiprone was found to effectively reduce the liver iron content in these 3 hornbills with iron storage disease. All 3 methods used to monitor the liver iron content (QIA, chemical analysis of liver biopsy samples, and MRI) had similar results, indicating that all of these methods should be considered for the diagnosis of iron storage disease and monitoring of liver iron content during treatment.

Deferiprone is a bidentate oral iron chelator used for the treatment of iron overload in people. The purpose of this study was to determine the pharmacokinetic disposition of deferiprone in the domestic pigeon (Columba livia) and to compare the results with a previous study in the white leghorn chicken. Deferiprone (DFP) was administered orally as a suspension at a single dose of 50 mg/kg to 10 iron-loaded (IL-DFP) pigeons and 10 non--iron-loaded controls (NIL-DFP). Six NIL-DFP birds were also administered deferiprone intravenously to determine the bioavailability of the drug after a 30-day washout period. To evaluate if deferiprone induces its own metabolism, the pharmacokinetic disposition of the drug was also studied in the IL-DFP group after oral therapy with deferiprone at a dosage of 50 mg/kg q12h for 30 days. For each phase, collected blood was analyzed for deferiprone by high-performance liquid chromatography to develop a plasma concentration versus time curve. Deferiprone was rapidly absorbed from the gastrointestinal tract, with plasma concentrations effective for iron chelation maintained for at least 8 hours after administration in iron-loaded birds. The half-life (mean +/- SD) for deferiprone given orally to the IL-DFP and NIL-DFP groups was 2.98 +/- 0.85 hours and 3.26 +/- 1.25 hours, respectively, and when intravenously administered was 3.79 +/- 1.23 hours. The half-life after 30 days of treatment was 3.42 +/- 1.18 hours. Oral bioavailability was 44%. This study demonstrated that oral absorption of deferiprone is acceptable, it does not induce its own metabolism, and the drug was widely distributed in the pigeon, as it was in the chicken, with a longer half-life than that reported in mammals. Minor interspecies variations in the pharmacokinetics of deferiprone exist between chickens and pigeons.

Deferiprone is a bidentate oral iron chelator used for the treatment of transfusional iron overload in people. The purpose of this study was to determine the pharmacokinetic disposition of deferiprone in the white leghorn chicken as a potential model upon which to base therapeutic regimens for the treatment of iron storage disease (hemochromatosis) in affected avian species. A suspension of deferiprone (DFP) was administered orally at a single dose of 50 mg/kg to 10 birds that were iron-loaded (IL-DFP) and 10 non--iron-loaded control birds (NIL-DFP). After a 30-day washout period, 5 birds from the NIL-DFP group were used for a bioavailability study of deferiprone administered intravenously at the same dose. Blood samples were collected at varying intervals over a 24-hour period and were analyzed for deferiprone by high-performance liquid chromatography, then plasma concentration versus time curves were developed. Deferiprone was rapidly absorbed from the gastrointestinal tract of the chicken, with plasma concentrations effective for iron chelation in humans (>20 micromol/L) maintained for at least 8 hours after oral dosing. The half-life (mean +/- SD) of the orally administered deferiprone in the IL-DFP and NIL-DFP groups was 2.91 +/- 0.78 hours and 3.61 +/- 0.90 hours, respectively, and was 2.42 +/- 0.24 hours for deferiprone administered intravenously. The mean oral bioavailability was 93%. Deferiprone is well absorbed and widely distributed in the chicken, with a longer half-life than reported in mammals.

The clinical use of oral Fe chelators for the treatment of Fe-storage disease in birds requires evaluation. In this study, the efficacy of the Fe chelator deferiprone in reducing hepatic Fe stores, its effects on hematologic, biochemical, and plasma Fe parameters, and its potential toxicity during a 30-day treatment period were investigated in a controlled setting using two model species, the white leghorn chicken (Gallus gallus f. domestica) and the domestic pigeon (Columba livia). A second phase of the study investigated deferiprone-related Fe elimination in the excreta. Deferiprone, administered orally at a dosage of 50 mg/kg twice daily to birds that had been experimentally Fe loaded, significantly reduced hepatic Fe concentrations compared with levels in Fe-loaded and non-Fe-loaded controls. There were no significant alterations in routine clinical hematologic or biochemical parameters, although decreased transferrin saturation was noted in both species. Side effects associated with deferiprone administration were decreased weight gain and significant decreases in plasma Zn concentrations. No mortalities occurred in the pigeons, but there were three deaths in the deferiprone-treated group of Fe-loaded chickens, most likely associated with acute reduction of Fe required for normal enzymatic processes. Histologic changes associated with deferiprone treatment were not noted. Deferiprone caused a dose-dependent increase of Fe in the excreta at oral dosages of 50 and 75 mg/kg once daily in both species. Deferiprone is a promising, orally active Fe chelator for the treatment of Fe overload in birds, although its potential side effects need to be considered.