Marbofloxacin is a bactericidal fluoroquinolone developed exclusively for veterinary medicine. The pharmacokinetic disposition of this drug was studied after oral administration of a single dose (10 mg/kg) to 8 adult Eurasian buzzards (Buteo buteo). Plasma concentrations of marbofloxacin were measured during the 48-hour period after drug administration. A maximum plasma concentration of 3.70 μg/ml was achieved at 2.92 hours. Marbofloxacin was relatively slowly absorbed after oral administration (absorption half-life of 1.57 hours) and demonstrated a high bioavailability (92.15%). The elimination half-life was 9.48 hours, and the mean residence time was 10.65 hours. When using a minimum inhibitory concentration (MIC) breakpoint of 0.25 μg/ml, the calculated antimicrobial efficacy of orally administered marbofloxacin was higher than the range considered optimal for a dosing regimen against pathogens with an equivalent MIC. A dosage of 10 mg/kg administered once daily appears to be appropriate for the treatment of most infections with gram-negative bacteria that affect Eurasian buzzards.

The effects of medetomidine-ketamine and diazepam-ketamine as injectable anesthetic combinations were compared in racing pigeons (Columba livia). Two groups of 6 pigeons of undetermined gender were used. Pigeons in group 1 were anesthetized with medetomidine (125 μg/kg) and ketamine (30 mg/kg) administered intramuscularly. At the first sign of recovery, the medetomidine antagonist atipamezole (65 μg/kg IM) was administered. Pigeons in group 2 were anesthetized with diazepam (2 mg/kg IM) and ketamine (60 mg/kg IM). Response to painful stimuli was recorded for each pigeon in both groups, and changes from baseline in heart and respiratory rates and body temperature were determined. The medetomidine-ketamine combination provided a deeper plane of anesthesia with better analgesia than did diazepam-ketamine, based on significant differences in reflex scores and heart-rate changes after painful stimuli. Recovery was rapid and smooth in pigeons given medetomidine-ketamine, whereas recovery was prolonged in pigeons given diazepam-ketamine. In the clinical study, the level of anesthesia achieved with medetomidine-ketamine was unreliable, with birds exhibiting violent wing flapping. We conclude that further controlled studies must be done in a clinical setting before practical recommendations can be made for using the combination of medetomidine-ketamine for anesthesia of pigeons.

Several reports implicate Encephalitozoon hellem, a microsporidian parasite first described in humans and later in birds, as the causative agent of severe disease in immunocompromised patients. This study was conducted to assess the prevalence of microsporidian spores shed in the droppings of lovebirds. During a 7-month period, a total of 198 apparently healthy lovebirds from 8 flocks in Texas were sampled, including 113 peach-faced lovebirds (Agapornis roseicollis), 32 masked lovebirds (Agapornis personata), and 53 Fischer's lovebirds (Agapornis fischeri). Smears made from cloacal swab samples of individual birds were stained with calcofluor white M2R stain and examined for the presence of spores. Microsporidian spores were identified in the droppings of 25% of the lovebirds sampled. Peach-faced and masked lovebirds were more likely to shed spores than were Fischer's lovebirds (χ² = 15.905, P < .001). No difference in spore shedding was found between juvenile and adult birds (χ² = 0.157, P = .692; odds ratio = 1.659; 95% CI, 0.736–3.736). Lovebirds (n = 111) were also assayed for psittacine beak and feather disease virus by polymerase chain reaction (PCR) testing of individual blood samples. Lovebirds that were PCR positive for psittacine beak and feather disease virus (n = 23) were approximately 3 times more likely to shed microsporidian spores than were lovebirds that were PCR negative (χ² = 3.981, P = .046; odds ratio = 2.6; 95% CI, 1.013–6.754). These results suggest that companion birds without obvious clinical illness commonly shed microsporidian spores. These birds may be a source of spore contamination for opportunistic infections in humans.

The kakapo (Strigops habroptilus) is a critically endangered New Zealand parrot. The presence of house sparrows (Passer domesticus) infected with a potentially pathogenic phage type of Salmonella enterica on the 2 islands that contain the remaining kakapo caused concern that this phage type might infect the kakapo and threaten their survival. This study sought to determine the presence or absence of Salmonella and Campylobacter species in the kakapo population of Codfish Island, New Zealand. Fecal and cloacal swab samples from kakapo were collected during an annual health examination and cultured for Salmonella and Campylobacter species. None of the cultures from the 39 birds sampled were positive for either organism. Results of this study suggest that kakapo on Codfish Island are not currently infected with these organisms. However, management changes have been made to reduce the risk of disease transmission from feral birds, and surveillance for these organisms in the kakapo will be continued.

We retrospectively examined plasma uric acid concentrations of swift parrots (Lathamus discolor) in samples collected during a period when a suspected toxin was causing renal tubular pathologic changes. The primary aim of this study was to investigate plasma uric acid concentrations from birds with existing renal compromise on 2 levels of dietary protein. There was a significant difference in the monthly pattern of plasma uric acid concentration between the birds that died and those that remained clinically normal. Birds that were fed a high-protein ration had a significantly different monthly pattern of plasma uric acid concentration than those birds fed a low-protein ration. We then evaluated the effects of an overnight fast and subsequent feeding on plasma uric acid concentrations in swift parrots. The preprandial plasma uric acid concentration, taken after a 14-hour fast, was not significantly different from the 2- and 6-hour postprandial concentrations. To further examine the effect of diet on plasma uric acid concentration, we examined the plasma of wild swift parrots feeding on nectar, pollen, and insects and of swift parrots from a private aviculturist feeding seed and commercial lorikeet nectar food. The highest levels of plasma uric acid were those of the captive swift parrots fed the mixed nectar and seed diet; plasma uric acid concentrations of the wild birds were lower than preprandial concentrations of captive parrots. It remains unclear whether increases in plasma uric acid concentrations were a consequence of renal tubular damage or of high dietary protein levels. However, the finding of low plasma uric acid concentrations in wild birds and high concentrations in captive birds provide support for the hypothesis that dietary protein levels provided to captive birds were in excess of requirements. As nectarivores, swift parrots might have lower protein requirements than granivorous parrots. However, confirmation of this hypothesis will require nitrogen balance studies as a direct assessment of protein metabolism. We hypothesize that dietary protein levels did not induce the renal disease but might have contributed to ongoing pathologic changes in the damaged kidneys.

This report details the investigation of renal disease associated with neurologic signs and deaths in a captive research colony of the endangered swift parrot (Lathamus discolor). The syndrome affected birds irregularly during 11 months from October 1999 to September 2000. Ten birds from 4 aviaries were clinically affected, and 9 birds died. The most common clinical signs were weight loss, neurologic dysfunction (ataxia and generalized tremors), and articular gout. At necropsy, common findings included gross nephropathy, visceral gout, and gonadal regression or inflammation. Histopathologic changes included renal tubular degeneration and accumulations of black crystals, assumed to be urates, in renal tubules and collecting ducts. These histopathologic changes are nonspecific and could be associated with a wide variety of nephrotoxins including, but not limited to, heavy metals, organic solvents, phenol, antibacterial agents, pesticides, and ethylene glycol. The syndrome was associated with the feeding of a high-protein diet and the presence of nesting boxes and other environmental factors. A number of potentially toxic substances were found in the swift parrots' environment, including nitrate fertilizer, zinc from galvanized wire, and potentially toxic wood fragments (Tasmanian sassafras [Atherosperma moschatum]). However, not all affected birds were exposed to these toxins, or diagnostic testing ruled them out of consideration. Regardless of the initial cause of renal damage, the overall renal pathologic changes were consistent with a urate nephropathy. There is still uncertainty as to the initial cause of the neurologic disease and renal damage despite the intensive investigation described here. The immediate deterioration of 2 swift parrots after the reintroduction of the high-protein diet led us to suspect that dietary levels of protein might be a contributing factor to the renal disease.

Trauma and skin defects are common presentations in companion and wild birds. Two barn owls (Tyto alba), an umbrella cockatoo (Cacatua alba), and an American crow (Corvus brachyrhynchos) were presented for varied skin wounds. Porcine small intestinal submucosa was used as a xenogeneic graft to repair wound defects in each bird. The wounds healed within 6 weeks in all 4 birds, with less intensive wound management than that required for healing by second intention. All birds returned to normal function.