Pharmacokinetics of a Single Intramuscular Injection of Long-Acting Ceftiofur Crystalline-Free Acid in Cattle Egrets ( Bubulcus ibis).

We determined the pharmacokinetic properties of ceftiofur crystalline-free acid (CCFA), a long-acting antibiotic, after a single intramuscular injection in cattle egrets ( Bubulcus ibis). A dose of 20 mg/kg was administered intramuscularly to 18 birds and blood samples were collected via jugular venipuncture at 1, 2, 4, 8, 12, 24, 48, 72, 96, 120, 144, 168, 192, 216, and 240 hours after CCFA administration. Plasma concentrations of ceftiofur free acid equivalents (CFAEs) were measured via high-performance liquid chromatography. The minimum inhibitory concentration (MIC) of 1 µg/mL was reached by 1 hour after administration and remained higher than the MIC for at least 72 hours in all birds. This target concentration is effective for many bacterial infections in avian species. The area under the plasma concentration versus time curve was 451.3 h*µg/mL, maximum plasma concentration was 16.22 µg/mL, time to maximum plasma concentration was 3.2 hours, mean harmonic half-life was 37.92 hours, and time that the concentrations of CFAEs were higher than the target MIC was a minimum of 72 hours.

Evaluating echocardiogram and indirect blood pressure results in male western lowland gorillas (Gorilla gorilla gorilla) during three phases of an anesthetic protocol.

Until the majority of the great ape population is trained for conscious cardiac evaluations, most individuals will require general anesthesia to perform echocardiograms. Within the veterinary community, concern exists that certain anesthetic protocols may exacerbate or artificially induce signs of cardiac disease. Because of potential cardiovascular effects, medetomidine has generally been used cautiously in patients with cardiac disease. The combination of ketamine and medetomidine is frequently used by many institutions because of its reversibility. To date, no published studies have obtained physiologic or echocardiographic parameters comparing different anesthetic protocols. In this study, with the use of seven adult male gorillas (Gorilla gorilla gorilla) with and without cardiac disease, echocardiographic and indirect blood pressure data during three phases of an anesthetic protocol were collected. The initial echocardiographic study was completed with ketamine/ medetomidine alone (5-7 mg/kg, i.m., and 0.05-0.07 mg/kg, i.m., respectively); the second study was completed after the addition of sevoflurane inhalant anesthesia to this procedure; and the third study was completed after reversal of medetomidine by administration of atipamezole (5:1 with the medetomidine dose given at induction). Without exception, ejection fractions were 15-25% lower under anesthesia with medetomidine as compared to ejection fractions after administration of atipamezole. Indirect blood pressures were higher on ketamine/ medetomidine, lower with addition of sevoflurane, and considerably lower after administration of atipamezole.

Semen characteristics and artificial insemination in rockhopper penguins (Eudyptes chrysocome chrysocome).

This work was performed as part of a multi-year study to determine the cause of the low fertility in captive rockhopper penguins (Eudyptes chrysocome chrysocome) and attempt to increase the fertility through artificial insemination (AI). Semen collection and characterization was performed on 14 male rockhopper penguins. The samples were evaluated for volume, sperm concentration, and sperm quality (motility, forward motility, viability, and morphology). There was a large variation between individuals and between collections for each individual. Mean volume of ejaculate was 0.24 ml. Mean concentration was 47.09 × 10(6) sperm/ml. Mean number of sperm per collection was 6.57 × 10(6). The mean motility was 49.4%. Mean forward motility was 1.7. Mean percentage of living sperm was 88.9%. Mean percentage of sperm with normal morphology was 69.4%. AI was performed on a total of 10 females using pooled semen samples. The birds were also allowed to naturally mate. Ten eggs were laid and three fertile eggs were produced, one of them hatched but died within 24 hr. Paternity testing was performed using 12 microsatellite loci, but unfortunately due to insufficient variability, the paternity of the chick and two embryos could not be determined.

Melanoma in the skin of a nurse shark (Ginglymostoma cirratum).

A female nurse shark, Ginglymostoma cirratum, estimated at 27 yr of age had a 5.5-yr history of a 6-cm black, raised nodular skin lesion located on the right side of the proximal tail. The lesion was diagnosed on biopsy as a slow-growing melanoma of the skin with no vascular invasion. The nurse shark was euthanized for systemic illness approximately 4.5 mo after diagnosis of the dermal melanoma. No evidence of metastasis was found on histopathologic evaluation of the skin and viscera.

Avian plasma chemistry analysis using diluted samples.

Clinical chemistry tests are essential for the diagnosis and monitoring of disease in birds. The small volume of blood that can be obtained from many avian species limits the use of routine in-house chemistry analyzers. The aim of this study was to examine the accuracy and precision of avian plasma chemistry values obtained by use of a benchtop analyzer in samples diluted with sterile water, as compared with undiluted samples. Whole blood samples were collected from 13 clinically healthy thick-billed parrots (Rhynchopsitta pachyrhyncha). The samples were placed in lithium heparin tubes and centrifuged and the plasma decanted. One aliquot was analyzed immediately using a VetScan benchtop analyzer with an avian-reptile-specific rotor that included 12 analytes. The remainder of the plasma was divided into two aliquots and stored at -80 degrees C until analysis. One of these aliquots was diluted 1:1, 1:1.5, 1:2, and 1:2.5 with sterile water to give final dilutions of 1:2, 1:2.5, 1:3, and 1:3.5, respectively. The other aliquot was pooled with the 12 other samples to create a plasma pool. The undiluted plasma pool and two final dilutions (1:2 and 1:3) of the pooled plasma were analyzed in replicate (n = 20) to determine intra- and interassay imprecision. Each dilution was analyzed using the avian-reptile rotor and the results multiplied by the appropriate dilution factor to obtain the final result. Significant differences were observed in clinical chemistry results obtained from diluted plasma samples for all analytes except aspartate aminotransferase, creatine kinase, and glucose. Uric acid concentration was not significantly different at dilutions of up to 1:3. Bile acids, globulins, and sodium concentrations were below the limit of detection in all diluted samples and were not statistically analyzed. Based on these results, dilution with sterile water is not recommended for biochemical analysis of avian plasma using the VetScan benchtop analyzer.

Semen collection and characterization in rockhopper penguins (Eudyptes chrysocome chrysocome).

Low egg fertility and hatchability is a common problem in captive populations of rockhopper penguins (Eudyptes chrysocome chrysocome). These conditions make sustaining a captive population challenging. A method for collecting and evaluating semen from rockhopper penguins was developed to assist in the evaluation of low egg fertility found in one captive population. Six adult male rockhopper penguins were conditioned to allow semen collection once a week from the start of breeding season until ejaculates no longer contained sperm. A total of 59 ejaculates was collected between 17 September and 31 December 2004. Forty-five of these samples were evaluated for volume, pH, sperm concentration, and sperm quality (motility, viability, and morphology). There was a large variation between individuals and between collections for each individual. The mean motility was 34.5% (+/- 22%). Mean volume of ejaculate was 0.23 ml (+/- .31 ml). Mean concentration was 16.9 x 10(6) sperm/ml (+/- 48.7 x 10(6) sperm/ml). Mean number of sperm per collection was 1.7 x 10(6) (+/- 4.2 x 10(6)). Mean percentage of living sperm was 82.9% (+/- 18.1%). Mean percentage of sperm with normal morphology was 82.1% (+/- 18.8%). Mean pH was 6.47 (+/- 0.49). During this season, only one of these males paired with a female. The pair produced one fertile egg, but the embryo died early in incubation. Male rockhopper penguins had low sperm concentration and low motility indicating that low male fertility may be contributing to the poor egg fertility rate. This work represents the first step in an ongoing study to improve captive breeding of rockhopper penguins.