An outbreak of avian mycobacteriosis caused by Mycobacterium intracellulare in little blue penguins (Eudyptula minor).

Mycobacterium intracellulare (MIT) was diagnosed postmortem by culture and supporting histopathology in seven birds from a flock of little blue penguins (Eudyptula minor) at the Henry Doorly Zoo (HDZ). These birds represented 20% of the deaths in the population over a 4 yr period. Clinical signs in affected birds included severe respiratory distress characterized by open-mouth breathing with chronic debilitation. On exam, plaques were noted in the larynx, trachea, and soft tissue of the caudal oropharynx. Index cases were identified on necropsy in two birds on loan to another institution in 2003. Following a case confirmed antemortem at the HDZ, a three-drug protocol of rifampin (15 mg/kg p.o. s.i.d.), ethambutol (15 mg/kg p.o. s.i.d.), and clarithromycin (10 mg/kg p.o. s.i.d.) was started on this bird in 2004 and extended to the entire flock in 2005. Gastric wash, fecal samples, and throat plaques were obtained antemortem on five birds within the flock, selected because of the presence of oral plaques, and tested by culture followed by a polymerase chain reaction assay. MIT was detected in gastric washes from four birds and in throat plaques from all five. Three more birds died during treatment. After the seventh bird died, antimicrobial susceptibility testing performed in July 2007 indicated that the MIT was now resistant to most antibiotics tested, including rifampin and ethambutol. The treatment regimen was changed to minocycline (10 mg/kg p.o. b.i.d.) and clarithromycin (10 mg/kg p.o. s.i.d.). Oral plaques were not seen on monthly rechecks of the flock through November 2008. The proposed mechanism of transmission is exposure to wild birds but the source has not been determined. These cases of avian mycobacteriosis caused by MIT are the first known cases reported in little blue penguins.

Gastrointestinal obstruction in penguin chicks.

A 7-day-old gentoo penguin (Pygoscelis papua) was found dead and postmortem examination revealed impaction of the ventriculus with feathers. A review of mortality in gentoo penguin chicks from 1997 to 2007 at that institution revealed another case of feather impaction of the ventriculus in a 4-week-old chick, a sibling of the previous chick. A third case of gastrointestinal impaction occurred in a 24-day-old king penguin (Aptenodytes patagonicus) with omphallitis and enteritis. In this chick, a fibrin mat produced a complete obstruction of the intestine at the level of Meckel's diverticulum.

Pharmacokinetics of florfenicol after a single intramuscular dose in white-spotted bamboo sharks (Chiloscyllium plagiosum).

This study evaluated the pharmacokinetics of florfenicol in the white-spotted bamboo shark (Chiloscyllium plagiosum). In addition to the pharmacokinetics, the potential application for treatment of bacterial meningitis was explored. A pilot study was used to compare doses of 30, 40, and 50 mg/kg i.m. Following that study, 10 adult sharks were administered a single i.m. dose of florfenicol at 40 mg/kg. Plasma and cerebrospinal fluid were collected and analyzed for florfenicol by a sensitive and specific high-pressure liquid chromatographic method. Pharmacokinetic analysis was performed using both non-compartmental and compartmental techniques. The absorption produced an average peak at 54 (+/-19) hr from the i.m. site of administration, and the half-life was prolonged, averaging 269.79 hr (+/-135.87). Florfenicol plasma concentrations peaked at an average of 11.85 microg/ml (+/-1.45) and were maintained above our target minimum inhibitory concentration of 4-8 microg/ml for at least 120 hr. Cerebrospinal fluid concentrations peaked at an estimated 9 microg/ml around 48 hr, surpassing the target minimum inhibitory concentration for at least 72 hr.

Xylazine-midazolam-ketamine versus medetomidine-midazolam-ketamine anesthesia in captive Siberian tigers (Panthera tigris altaica).

Two alpha2-adrenoceptor agents, xylazine and medetomidine, in combination with midazolam and ketamine safely and effectively immobilized Siberian tigers (Panthera tigris altaica). The medetomidine protocol used smaller drug volumes, and induction and recovery times were shorter. Although cardiopulmonary abnormalities were noted, none were likely to be life threatening.