Preliminary Pilot Study of Itraconazole After a Single Oral Dose of a Veterinary Formulation Solution in African Penguins (Spheniscus demersus).

Aspergillosis is a common cause of morbidity and mortality in captive penguins. Itraconazole, an antifungal drug, is commonly used to treat aspergillosis infections in avian species; however, commercially available human formulations are costly, and studies have shown the effectiveness of compounded formulations to be unreliable. The US Food and Drug Administration (FDA) recently approved a veterinary formulation of itraconazole, Itrafungol, for use in cats. This study provides preliminary results from limited sampling evaluating whether this veterinary formulation is suitable for future studies in the African penguin (Spheniscus demersus). A 20 mg/kg PO itraconazole dose was administered to 9 African penguins. Blood samples were taken over the course of 24 hours; each sample was collected from a different bird to minimize stress to the animals. Plasma was analyzed by high-performance liquid chromatography for concentrations of itraconazole. The drug was absorbed in all penguins, and plasma concentrations in 5 of 9 penguins (56%) were found to be greater than the established therapeutic dose of 1.0 µg/ mL. To our knowledge, this is the first study that has investigated a 20 mg/kg dose of itraconazole in a penguin species. The small sample size limits the conclusions that can be drawn from this preliminary study. Nonetheless, we demonstrate encouraging evidence that the FDA-approved formulation of oral itraconazole solution should be considered for future study as a cost-effective treatment for aspergillosis in African penguins and other avian species.

Erosive Enteritis and Intestinal Obstructions Caused by Decomposed Granite in a Flock of Lesser Flamingos (Phoeniconaias minor).

Decomposed granite is a material commonly used in zoos as a base for flamingo exhibits. In 2012, the artificial turf over the decomposed granite in the Fort Worth Zoo flamingo exhibit was removed and pressure washed, the granite was replaced, and the turf was then restretched in place. Approximately 8 months later, 3 lesser flamingos (Phoeniconaias minor) showed signs of lethargy and hematochezia. Results of physical examination revealed poor body condition in all birds, with variable hematologic abnormalities, including anemia, hypoproteinemia, and electrolyte disturbances. Radiographs of birds showed large amounts of radiopaque material in the ventriculus and dilated intestinal loops. Two birds died either during treatment or surgery, and 1 bird was euthanatized. Postmortem examination of all 3 birds revealed large amounts of fine, granite-like material in the ventriculus and intestines, severe congestion of intestinal mucosa, and obstruction of intestinal lumen by caseous plugs surrounded by fecal material. Microscopic evaluation of the material removed from the ventriculus showed birefringent crystals that corresponded to microscopic silica grains, consistent with the decomposed granite from the exhibit. Histologic examination of tissues showed marked chronic erosive colitis, mild erosive proventriculitis, and lesions in the muscular layer of the ventriculus. Subsequently, 82 remaining flamingos in the flock were radiographed. Results showed the same material in the ventriculus of most birds, but no intestinal obstructions were identified. Different treatment techniques were attempted unsuccessfully to remove the material from the flamingos that had the largest amount of decomposed granite in their gastrointestinal tracts. Ultimately, all birds were treated with oral gastrointestinal protectants, adsorbents, laxatives, and lubricants, along with antibiotics administered in drinking water. No further mortalities occurred once medical treatments were implemented.

Population pharmacokinetics of itraconazole solution after a single oral administration in captive lesser flamingos (Phoeniconaias minor).

Aspergillosis is an infectious, non-contagious fungal disease of clinical importance in flamingo collections. Itraconazole is an antifungal drug commonly used in the treatment and prophylaxis of avian aspergillosis. Studies have shown that dosage regimes in birds vary based on different itraconazole presentation and administration methods. This investigation used a population pharmacokinetic approach to study itraconazole in lesser flamingos. Itraconazole was administered orally at 10 mg/kg to 17 flamingos. A sparse blood sampling was performed on the subjects, and samples were collected at 1, 2, 3, 5, 8, 12, 16, 21, and 24 hr post-drug administration. Twelve flamingos were sampled three times, three birds bled twice and two sampled once. Itraconazole in plasma was quantified using high-pressure liquid chromatography (HPLC). A one-compartment pharmacokinetic model with first order absorption was fitted to the data using nonlinear mixed effects modeling (NLME) to determine values for population parameters. We identified a long half-life (T½) of more than 75 hr and a maximum plasma concentration (CMAX ) of 1.69 µg/ml, which is above the minimal inhibitory concentrations for different aspergillus isolates. We concluded that plasma drug concentrations of itraconazole were maintained in a population of flamingos above 0.5 ug/ml for at least 24 hr after a single oral dose of 10 mg/kg of itraconazole solution.

Hematology of Free-ranging and Managed Texas Horned Lizards ( Phrynosoma cornutum).

The Texas horned lizard ( Phrynosoma cornutum) is a threatened species in Texas, US (federal category C2). Causes for population declines in this species are likely multiple. Disease and health assessments using traditional methods, including hematology, have been minimally studied in Phrynosoma spp. Apparently healthy, free-ranging Texas horned lizard from four locations in Texas ( n=53) and captive Texas horned lizards maintained at the Fort Worth Zoo ( n=16) were sampled to establish hematologic reference intervals. Within the populations studied, total leukocyte, heterophil, and eosinophil counts were higher in managed compared to free-ranging lizards. Leukocyte and heterophil counts of all lizards were lower during the ovipositional months of June and July.

Population pharmacokinetics of a single dose of meloxicam after oral and intramuscular administration to captive lesser flamingos (Phoeniconaias minor).

OBJECTIVE To determine the pharmacokinetics of a single dose of meloxicam after IM and oral administration to healthy lesser flamingos (Phoeniconaias minor) by use of a population approach. ANIMALS 16 healthy captive lesser flamingos between 1 and 4 years of age. PROCEDURES A single dose of meloxicam (0.5 mg/kg) was administered IM to each bird, and blood samples were collected from birds at 3 (n = 13 birds), 2 (2), or 1 (1) selected point between 0 and 13 hours after administration, with samples collected from birds at each point. After a 15-day washout period, the same dose of meloxicam was administered PO via a red rubber tube and blood samples were collected as described for IM administration. Pharmacokinetic values were determined from plasma concentrations measured by high-performance liquid chromatography. RESULTS Plasma drug concentrations after IM administration of meloxicam reached a mean ± SD maximum value of 6.01 ± 3.38 µg/mL. Mean area under the concentration-versus-time curve was 17.78 ± 2.79 µg•h/mL, and mean elimination half-life was 1.93 ± 0.32 hours. Plasma concentrations after oral administration reached a mean maximum value of 1.79 ± 0.33 µg/mL. Mean area under the curve was 22.16 ± 7.17 µg•h/mL, and mean elimination half-life was 6.05 ± 3.53 hours. CONCLUSIONS AND CLINICAL RELEVANCE In lesser flamingos, oral administration of meloxicam resulted in higher bioavailability and a longer elimination half-life than did IM administration, but the maximum plasma concentration was low and may be insufficient to provide analgesia in flamingos. Conversely, IM administration achieved the desired plasma concentration but would require more frequent administration.