EVALUATION OF NONINVASIVE OSCILLOMETRIC BLOOD PRESSURE MONITORING IN ANESTHETIZED BENNETT'S WALLABIES (MACROPUS RUFOGRISEUS).

The objective of this study was to determine the accuracy of a noninvasive oscillometric method in relation to invasively measured blood pressure in anesthetized Bennett's wallabies (Macropus rufogriseus) and also to compare the accuracy of two commonly used oscillometric blood pressure monitors (manufactured by Cardell and Datascope). Eleven animals were anesthetized, and each animal was instrumented with an arterial catheter in the right medial metatarsal artery connected to a pressure transducer to obtain invasive measurements of systolic (SAP), diastolic (DAP), and mean (MAP) arterial blood pressure as well as a pressure waveform. A cuff connected to an oscillometric device was placed on the base of the tail for noninvasive measurements. Paired data from noninvasive and invasive blood pressure measurements (SAP, DAP, and MAP) were obtained every 5 min for 60 min. Bland-Altman plots were used to compare invasive and noninvasive measurements and calculate bias and 95% limits of agreement for SAP, DAP, and MAP. For both monitors, the bias of SAP, DAP, and MAP was significant, although the bias of the Cardell was consistently lower than that of the Datascope for all parameters. Limits of agreement were wide for all parameters. In conclusion, when using an oscillometric blood pressure monitor on anesthetized Bennett's wallabies, trends in blood pressure may be monitored, although all displayed readings may not represent the true blood pressure measurement. Indirect measurements of blood pressure made with the oscillometric device cannot substitute for direct measurements.

TREATMENT OF MYCOTIC RHINOSINUSITIS IN A BENNETT'S WALLABY ( MACROPUS RUFOGRISEUS) USING TOPICAL VORICONAZOLE SUSPENDED IN A REVERSE THERMODYNAMIC PLURONIC GEL.

An approximately 4-yr-old female Bennett's wallaby ( Macropus rufogriseus) was evaluated for chronic left-sided facial swelling and nasal discharge. Computed tomography, endoscopy, biopsy, mycologic culture, and panfungal polymerase chain reaction were consistent with destructive mycotic rhinosinusitis. The patient's infection was treated with a long-term injectable antibiotic, oral antifungal therapy, and multiple intranasal infusions of voriconazole suspended in a reverse thermodynamic pluronic gel. This case represents the first documented case of mycotic rhinosinusitis in a macropod and underlines the importance of advanced cross-sectional imaging in the diagnosis, monitoring, and management of nasal cavity disease in zoo animals.

USE OF ORAL FLUOXETINE FOR THE TREATMENT OF ABNORMAL AGGRESSION IN TWO RED-NECKED WALLABIES (MACROPUS RUFOGRISEUS).

: Abnormal inter- and intraspecies aggression, perceived to be anxiety related, was identified in two male red-necked wallabies (Macropus rufogriseus) housed within a zoo. Aggressive episodes were directed at conspecifics, other exhibit animals, and, in one case, human caretakers. The clinical use of oral fluoxetine (0.5 mg/kg po bid) for a period of approximately 4 mo was effective in eliminating aggression towards humans and other animals in these two individuals. There was no evidence of recrudescence of aggression in either case following discontinuation of therapy for up to 3 yr posttreatment. Other than a period of mild transient sedation in one animal, side effects were not noted with fluoxetine treatment in these cases. Additional studies on the pharmacokinetics and side effects of fluoxetine treatment for anxiety behaviors are warranted in wallabies.

NEWLY DESCRIBED TOXOPLASMA GONDII STRAIN CAUSES HIGH MORTALITY IN RED NECKED WALLABIES (MACROPUS RUFOGRISEUS) IN A ZOO.

This manuscript describes an outbreak of fatal toxoplasmosis in wallabies. Ten adult red necked wallabies (Macropus rufogriseus) were imported from New Zealand to the Virginia Zoo. Agglutination testing upon admission into quarantine showed all animals to be negative for antibodies to Toxoplasma gondii. Nine of these wallabies died from acute toxoplasmosis within 59-565 (average 224) days after being moved onto exhibit. Clinical signs included lethargy, diarrhea, tachypnea, and ataxia that progressed rapidly; death without premonitory signs occurred in one case. Histopathologic examination revealed interstitial pneumonia, encephalomyelitis, myositis, enteritis, and myocarditis. The diagnosis was confirmed through serologic, histopathologic, and polymerase chain reaction (PCR) testing. Multilocus PCR-RFLP (restriction fragment length polymorphism) genotyping revealed that the first six animals were infected by a previously undiscovered Toxoplasma gondii genotype, designated as ToxoDB PCR-RFLP genotype No. 263. These six cases survived for an average of 118 days on exhibit before succumbing to toxoplasmosis. The other three wallabies were infected with a Toxoplasma gondii strain of ToxoDB PCR-RFLP genotype No. 4, which is a common strain type circulating in wild animals in North America. These three cases survived for an average of 435 days on exhibit before succumbing to toxoplasmosis. The outbreaks of toxoplasmosis in these wallabies are likely from two different sources. Furthermore, the results highlight Toxoplasma gondii PCR-RFLP genotyping in parasite diagnosis and understanding parasite transmission and potential mitigation procedures.

COMPARISON OF MEDETOMIDINE-KETAMINE AND BUTORPHANOL-AZAPERONE-MEDETOMIDINE IN CAPTIVE BENNETT'S WALLABIES (MACROPUS RUFOGRISEUS).

The objective of this study was to compare a traditional partially reversible medetomidine-ketamine sedation with a more reversible butorphanol-azaperone-medetomidine combination in Bennett's wallabies ( Macropus rufogriseus ) maintained in a zoological collection. Fourteen animals were divided into two treatment groups. Individuals in group 1 received an intramuscular (i.m.) injection of butorphanol (0.54 ± 0.05 mg/kg), azaperone (0.22 ± 0.02 mg/kg), and medetomidine (0.16 ± 0.02 mg/kg). Individuals in group 2 received an i.m. injection of ketamine (5.43 ±1.16 mg/kg) with medetomidine (0.05 ± 0.014 mg/kg). For group 1, sedation was reversed with atipamezole (0.81 ± 0.069 mg/kg i.m.) and naltrexone (1.08 ± 0.09 mg/kg i.m.). For group 2, sedation was reversed with atipamezole (0.27 ± 0.056 mg/kg i.m.). There were no significant differences between the groups in mean time to induction, time spent on gas anesthesia, or time to standing after reversal was administered. Animals in both groups required supplemental gas anesthesia to facilitate intubation. No adverse reactions or effects were noted with either protocol; however, the BAM protocol did not provide sufficient sedation for handling in all animals and may not be suitable for use in this species.

SURGICAL CORRECTION OF A CERVICAL SPINAL FRACTURE IN A BENNETT'S WALLABY (MACROPUS RUFOGRISEUS).

Macropods are susceptible to trauma, and fractures of the cervical vertebrae due to collisions are relatively common. A 4-yr-old, intact male Bennett's wallaby (Macropus rufogriseus) was presented acutely nonambulatory and tetraparetic but with motor function present in all limbs. Cervical radiographs revealed a C4 vertebral fracture. Surgical stabilization was obtained through a ventral midline approach whereby the vertebral bodies were distracted and then secured with screws and polymethylmethacrylate (PMMA). Postoperative radiographs revealed restoration of the spinal canal and appropriate implant placement. The patient was discharged 4 days postoperatively and gradually recovered full neurologic function per the owner over the ensuing 10 wk. Subsequent radiographs obtained 10.5 mo postoperatively revealed a healed fracture with stable implants. The ventral spinal distraction and stabilization technique using screws and PMMA, as are used in the domestic dog, was successful in this wallaby despite its smaller vertebral size and comparable lack of soft-tissue support.

Regional Anesthesia of the Dentition in Bennett's Wallaby (Macropus rufogriseus): Anatomical Landmarks and Approaches Assessed with Computed Tomography and Gross Dissection.

Dental disease is common in captive-managed macropods, including Bennett's wallabies, and is a significant cause of morbidity and mortality. Dental extractions and debridement of diseased tissue is often necessary for those undergoing treatment for severe dental disease. Regional anesthesia of the dentition is considered standard of care for domestic animals undergoing orofacial surgery, however, it is not routinely performed in macropods due to limited information on dental anatomy and block approaches. Regional block descriptions for the infraorbital, maxillary, inferior alveolar, and mental blocks in domestic dogs and cats were evaluated and adapted for use in Bennett's wallabies based on descriptions of their anatomy and examination of 2 skulls. These approaches were then performed on cadaver heads with iohexol and methylene blue dye, and block placement was assessed on computed tomography scans and by gross dissection. All block approaches described in this study resulted in appropriate placement of regional anesthesia of the dentition in Bennett's wallabies. They can thus be used by clinicians to improve the intra and postoperative pain control of patients and provide a high level of veterinary care.

Fatal toxoplasmosis associated with an atypical Toxoplasma gondii strain in a Bennett's wallaby (Macropus rufogriseus) in Spain.

Toxoplasmosis is often fatal in captive wallabies, but the causes of this high susceptibility are not well understood. Here, we report fatal toxoplasmosis in a Bennet's wallaby (Macropus rufogriseus) due to an atypical Toxoplasma gondii strain for the first time in Europe. The wallaby was from a colony of 7 Bennet's wallabies that died over a 17-month period at a safari-zoological park in northeastern Spain. Only one of these wallabies was examined at necropsy. T. gondii-like organisms were detected by histological examination in several tissues and the diagnosis was confirmed through detection of T. gondii DNA by PCR. A nested PCR-based assay detected the 200- to 300-fold repetitive 529 bp DNA fragment of T. gondii in a sample of brain tissue. Genotyping analysis with 15 single-copy microsatellite markers was performed on this positive DNA sample and revealed an atypical genotype. Atypical genotypes are frequently associated with severe forms of toxoplasmosis in humans. The present report highlights the possible implications of the introduction of new atypical, more pathogenic T. gondii strains, to non-endemic areas.