Jennifer N. Langan

OCULAR BACTERIAL FLORA, TEAR PRODUCTION, AND INTRAOCULAR PRESSURE IN A CAPTIVE FLOCK OF HUMBOLDT PENGUINS (SPHENISCUS HUMBOLDTI)

Abstract The purpose of this study was to determine normal ocular surface bacterial flora, tear production, and intraocular pressure in a captive flock of Humboldt penguins, Spheniscus humboldti. Twenty-eight healthy penguins were studied and equally divided between fresh- and saltwater habitats. The population consisted of 15 female and 13 male penguins, ranging from 3–20 years of age. Following complete ophthalmic exam, 4 penguins with cataracts were removed from the study. Eight penguins from each habitat were randomly selected for ocular surface aerobic bacterial culture. Corynebacterium spp. and Staphylococcus spp. were the most common isolates. Twenty-five organisms consisting of 17 species, and 15 organisms consisting of 9 species, were identified in fresh- and saltwater groups, respectively. Tear production and intraocular pressures were evaluated on 24 penguins with normal ocular exams. The range and mean (±standard deviation) tear production, measured with the Schirmer tear test, was 1–12 mm/min and 6.45 mm/min ± 2.9, respectively. The mean tear production for penguins housed in the freshwater habitat was greater (8.5 mm/min) than those in saltwater (4.8 mm/min). The range and mean (±standard deviation) intraocular pressure, measured by applanation tonometry using a Tono-Pen XL® tonometer, was 10–27 mmHg and 20.36 mmHg ± 4.1, respectively. This data should be utilized as a reliable resource for those involved in avian and zoo medicine.

Cardiopulmonary and sedative effects of intramuscular medetomidine-ketamine and intravenous propofol in ostriches (Struthio camelus).

Abstract Eight captive ostriches (Struthio camelus), ranging in age from 9 to 11 months, were given a combination of medetomidine and ketamine, administered intramuscularly, and propofol, administered intravenously, for induction and maintenance of anesthesia. Medetomidine (80 μg/kg IM) and ketamine (2 mg/kg IM) resulted in profound sedation and sternal recumbency within a mean time of 14.6 ± 10.0 minutes in 6 birds. Two birds remained standing but were moderately sedated. Propofol, used for induction (3 mg/kg IV) and maintenance (0.2 mg/kg/min constant rate infusion) of anesthesia, enabled intubation and provided muscle relaxation sufficient for restraint lasting 30 minutes. Apnea was observed after propofol administration, but spontaneous ventilation resumed within 60 to 90 seconds. All birds were bradycardic throughout the anesthetic event. Both the heart rate and the cloacal body temperature decreased significantly at 25 and 30 minutes, respectively, after induction. By 5 minutes after induction, the respiratory rate increased significantly and remained high throughout the remainder of the 30-minute evaluation period. During the anesthetic period, systolic, mean, and diastolic blood pressures, as well as arterial pH, arterial oxygen and carbon dioxide partial pressures, and end tidal carbon dioxide partial pressure showed no significant changes. The relative arterial oxygen saturation (SpO2) was significantly elevated at 15, 25, and 30 minutes after induction. The SpO2 was less than 90% at 2, 5, 10, and 20 minutes after induction; however, arterial blood gas analysis indicated adequate arterial oxygenation. Anesthetic reversal with the α2-antagonist atipamezole (400 μg/kg, one half IV and one half SC) was smooth and resulted in a mean recovery time of 21.0 ± 7.3 minutes. The combination of IM medetomidine-ketamine and IV propofol used in this study proved to be effective for sedation as well as the induction and maintenance of anesthesia in captive ostriches.

Pharmacokinetics of long-acting ceftiofur crystalline-free acid in helmeted guineafowl (Numida meleagris) after a single intramuscular injection

OBJECTIVE To evaluate the elimination pharmacokinetics of a single i.m. injection of a long-acting ceftiofur preparation (ceftiofur crystalline-free acid [CCFA]) in healthy adult helmeted guineafowl (Numida meleagris). ANIMALS 14 healthy adult guineafowl. PROCEDURES 1 dose of CCFA (10 mg/kg) was administered i.m. to each of the guineafowl. Blood samples were collected intermittently via jugular venipuncture over a 144-hour period. Concentrations of ceftiofur and all desfuroylceftiofur metabolites were measured in plasma via high-performance liquid chromatography. RESULTS No adverse effects of drug administration or blood collection were observed in any bird. The minimal inhibitory concentration (MIC) for many bacterial pathogens of poultry and domestic ducks (1 μg/mL) was achieved by 1 hour after administration in most birds and by 2 hours in all birds. A maximum plasma concentration of 5.26 μg/mL was reached 19.3 hours after administration. Plasma concentrations remained higher than the MIC for at least 56 hours in all birds and for at least 72 hours in all but 2 birds. The harmonic mean ± pseudo-SD terminal half-life of ceftiofur was 29.0 ± 4.93 hours. The mean area under the curve was 306 ± 69.3 μg•h/mL, with a mean residence time of 52.0 ± 8.43 hours. CONCLUSIONS AND CLINICAL RELEVANCE A dosage of 10 mg of CCFA/kg, i.m., every 72 hours in helmeted guineafowl should provide a sufficient plasma drug concentration to inhibit growth of bacteria with an MIC ≤ 1 μg/mL. Clinical use should ideally be based on bacterial culture and antimicrobial susceptibility data and awareness that use of CCFA in avian patients constitutes extralabel use of this product.

West Nile Virus Seroconversion in Penguins After Vaccination with a Killed Virus Vaccine or a DNA Vaccine

Abstract To investigate the serologic response of penguins to West Nile virus (WNV) vaccines, four species of exclusively indoor-housed penguins, negative for WNV by serology, were evaluated: Humboldt (Spheniscus humboldti), Magellanic (Spheniscus magellanicus), Gentoo (Pygoscelis papua), and Rockhopper (Eudyptes chrysoscome) penguins. Birds were inoculated with either a killed virus vaccine or a plasmid-mediated DNA WNV vaccine, and postinoculation serology was evaluated. Both vaccines induced seroconversion in all four species, and no adverse reactions were noted. Postvaccination serology results varied across species and vaccine types. However, in all four species, the killed virus vaccine resulted in a greater seroconversion rate than the DNA vaccine and in a significantly shorter time period. Additionally, the duration of the seropositive titer was significantly longer in those birds vaccinated with the killed virus vaccine compared with those vaccinated with the DNA vaccine. A subset of unvaccinated penguins serving as negative controls remained negative throughout the duration of the study despite the presence of WNV in the geographic locations of the study, suggesting that indoor housing may minimize exposure to the virus and may be an additional means of preventing WNV infection in penguins.

Orthoreovirus Infection and Concurrent Cryptosporidiosis in Rough Green Snakes (Opheodrys Aestivus): Pathology and Identification of a Novel Orthoreovirus Strain via Polymerase Chain Reaction and Sequencing

Reoviruses are nonenveloped, segmented, double-stranded RNA viruses capable of infecting a wide range of invertebrate, vertebrate, fungus, and plant hosts. Though sporadic infection has been reported in a variety of reptilian species, infection of rough green snakes (Opheodrys aestivus) has not been previously described. Five wild-caught, adult rough green snakes were obtained by a zoological institution. Clinical deterioration was first noted in all snakes after 3 weeks in quarantine. Despite treatment, clinical decline progressed, and all 5 snakes died or were euthanized by 48 days post-arrival. Moderate, multifocal, acute, necrotizing hepatitis with hepatocellular syncytia was diagnosed in 1 snake. Two additional snakes had severe, diffuse, subacute to chronic pancreatitis. All 5 snakes had gastroenteric cryptosporidiosis. Electron microscopic examination of liver from the snake with hepatic lesions revealed scattered hepatocytes containing 1 or more intranuclear clusters of approximately 90 nm in diameter viral particles arranged in loose arrays. Polymerase chain reaction (PCR) amplification of a segment of the reovirus RNA-dependent RNA polymerase gene was performed on RNA extracted from tissues of all 5 snakes. PCR amplification of samples extracted from the snake with hepatic lesions resulted in a 109–base pair (bp) product. Phylogenetic analyses indicated the virus was a novel strain distinct from other reoviruses at a level consistent with species difference. The source of infection was unknown. PCR amplification of samples extracted from the other 4 snakes was negative.

TYZZER'S DISEASE IN A RED PANDA {AILURUS FULGENS FULGENS)

Abstract A debilitated 9-yr-old female red panda (Ailurus fulgens fulgens) with a recent history of corticosteroid administration displayed anorexia, depression, and diarrhea for 2 days. Blood work revealed a moderate nonregenerative anemia, leukocytosis, hypokalemia, hyperbilirubinemia, and mildly elevated alanine aminotransferase and aspartate aminotransferase. Serology was negative for occult heartworm, Toxoplasma gondii, feline leukemia virus, feline infectious peritonitis, feline immunodeficiency virus, and canine distemper virus. Electron microscopy of the feces demonstrated corona-like virus particles. The panda died 3 days after initial presentation. Histologic findings included multifocal, acute, hepatic necrosis and diffuse, necrotizing colitis. Liver and colon lesions contained intracellular, curved, spore-forming, gram-negative, silver-positive rods morphologically consistent with Clostridium piliforme. This panda most likely contracted Tyzzers disease subsequent to having a compromised immune system after corticosteroid administration and concurrent disease.

Metabolic bone disease in juvenile Humboldt penguins (Spheniscus humboldti): investigation of ionized calcium, parathyroid hormone, and vitamin D3 as diagnostic parameters.

Abstract Three cases of metabolic bone disease (MBD) were identified in juvenile Humboldt penguins (Spheniscus humboldti) in a zoological collection. Diagnosis, monitoring, and treatment were challenging, in part because radiographs and traditional serum biochemistries did not provide adequate information to guide appropriate clinical management. Normal values for ionized calcium (iCa), 25-hydroxyvitamin D3 [25-(OH) D3], and parathyroid hormone (PTH) have not been reported for any species in the order Sphenisciformes. This study aimed to establish reference ranges for these parameters to provide a method for assessing clinical cases of MBD and other disease processes. iCa was measured in 33 healthy adult birds from two zoological collections by using a portable clinical analyzer. iCa also was measured from 14 of these birds at a commercial laboratory. Mean and standard deviation were determined to be 1.21 ± 0.09 and 1.29 ± 0.10 mmol/L, respectively. Limited data exist on iCa in avian species, but these results are consistent with other reports and provide a useful clinical parameter. Analysis of PTH and 25-(OH) D3 was performed at a commercial laboratory on samples from 14 healthy adult penguins in one collection. Means and standard deviations for PTH and 25-(OH) D3 were 0.8 ± 0.3 pmol/L and 3.7 ± 2.4 nmol/L, respectively. These results are near the minimal functional detectable limits of the assays; raising uncertainty about the validity and usefulness of currently available PTH and 25-(OH) D3 tests in this species.

Evaluation of MS-222 (Tricaine Methanesulfonate) and Propofol as Anesthetic Agents in Sonoran Desert Toads (Bufo alvarius)

ABSTRACT Toads in the genus Bufo are commonly kept in pet, research, and zoological settings and may require anesthesia during veterinary care. Limited information is available comparing anesthetic protocols in most amphibian species. The purpose of this study was to evaluate the clinical and cardiopulmonary effects of tricaine methanesulfonate (MS-222) and propofol in Sonoran desert toads (Bufo alvarius). Nine juvenile Sonoran desert toads were anesthetized with an immersion bath of 1 g/L MS-222 and 35 mg/kg intracoelomic propofol with a minimum 2-wk wash-out period between trials. Heart rate, respiratory rate, and reflexes (righting, escape, corneal, superficial pain, and deep pain) were monitored every 5 min for the first 90 min and then every 10 min for the next 90 min during both anesthetic trials. Surgical anesthesia was defined as complete loss of all measured reflexes. MS-222 produced surgical anesthesia in 100% (9/9) of toads, whereas propofol produced surgical anesthesia in 11.1% (1/9). Mean induction time for the MS-222 trial was 19.9 min (SD: 5.4, Min–Max: 13–30), with mean duration of surgical anesthesia 23.9 min (SD: 10.8, Min–Max: 10–42). Mean recovery time after removal from the MS-222 bath was 85.3 min (SD: 18.5, Min–Max: 60–110). Righting reflex was lost in all animals in the propofol trial at a mean of 23.9 min (SD: 5.5, Min–Max: 20–35) following administration. A single animal in the propofol trial reached a surgical plane of anesthesia at 25 min post-administration, with surgical anesthesia lasting for 50 min. Mean time to recovery following administration of propofol was 145 min (SD: 47.2, Min–Max: 60–180); one toad was not fully recovered at the end of the monitoring period. Heart rate was not found to significantly (P > 0.05) change from baseline at any monitoring point for either anesthetic protocol. Respiratory rate was found to decrease significantly (P < 0.05) at all time points between 5 and 65 min in the MS-222 trial and between 10 and 130 min in the propofol trial. MS-222 at 1 g/L immersion was found to reliably produce surgical anesthesia in Sonoran desert toads with a faster onset of action and recovery when compared to propofol administered intracoelomically at 35 mg/kg.

Comparison of the Anesthetic Effects of Oral Transmucosal Versus Injectable Medetomidine in Combination with Tiletamine-Zolazepam for Immobilization of Chimpanzees (Pan troglodytes)

Abstract Seventeen adult chimpanzees (Pan troglodytes) with an average age of 37 yr were immobilized with a combination of tiletamine-zolazepam (TZ) and medetomidine (MED) by one of two modes of delivery. Group A animals received the drug combination intramuscularly at 3 mg/kg and 0.05 mg/kg, respectively. Animals in group B received MED by oral transmucosal administration, meaning oral delivery with presumptive transmucosal absorption. MED at 0.1 mg/kg was mixed with marshmallow crème, and delivery was followed by 3 mg/kg of TZ intramuscularly. Chimpanzees from both groups were recovered after administration of atipamezole at 0.3 mg/kg intramuscularly. All chimpanzees were compliant with oral transmucosal drug administration, although two chimpanzees preferred oral MED mixed with applesauce. All animals exhibited some anxiety and excitatory behavior associated with darting, but this was reduced in group B, which was premedicated with oral transmucosal MED. The mean time from TZ administration to sedation sufficient for human contact was 16.4 and 14.7 min with and without oral transmucosal premedication, respectively. The mean time for recovery for those chimpanzees given oral transmucosal premedication was 13.8 min, which was significantly shorter than the time of recovery for the group not given oral premedication (P  =  0.02). Oral transmucosal administration of MED provided light sedation in 16 of 17 chimpanzees to the level of arousable recumbency and a heavier sedation in one chimpanzee with no adverse side effects. TZ combined with MED by either oral transmucosal or injectable administration provided safe, heavy, long sedation with rapid, smooth, uneventful recoveries.

FATAL DISSEMINATED ENCEPHALITOZOONOSIS IN A CAPTIVE, ADULT GOELDI'S MONKEY (CALLIMICO GOELDII) AND SUBSEQUENT SEROSURVEY OF THE EXPOSED CONSPECIFICS

Abstract A captive, adult male Goeldis monkey (Callimico goeldii) (GM) presented in acute respiratory distress 4 yr after importation into the United States from Europe. Radiographs and echocardiogram were consistent with heart failure. The monkey died within 24 hr of presentation. Necropsy findings included multicentric arteritis and aortitis with aneurysm associated with microsporidian organisms morphologically consistent with Encephalitozoon species. Polymerase chain reaction confirmed organisms were Encephalitozoon cuniculi. Sequence analysis of amplicons generated by using primers specific for the polar tube protein of E. cuniculi determined the organism to be genotype II. An E. cuniculi serosurvey of potentially exposed conspecifics that represented approximately 40% of the captive GM population in the United States was conducted. Multiple individuals that had been imported from Europe with the individual of this report were seropositive via an immunofluorescent antibody assay for E. cuniculi. Multiple samples were available from 3 individuals that demonstrated a decrease in titer or reversion to seronegative status within 3 yr of initial positive status. All other GM were negative on serology. This case is unique in that the genotype identified (genotype II) was different than the genotype (genotype III) reported in other New World primate (NWP) species, the patterns of arteritis were different from the typical pattern of microsporidial vasculitis described in other species, and clinical disease was observed in an adult. Most reported cases of clinical disease secondary to E. cuniculi in NWP have been in neonates and juveniles.