Michael R. Loomis

TROMBICULID MITES (HANNEMANIA SP.) IN CANYON TREE FROGS (HYLA ARENICOLOR)

Abstract Six wild-caught, captive canyon tree frogs (Hyla arenicolor) purchased as a group and housed at the North Carolina Zoological Park were diagnosed with intradermal Hannemania mites, the first described infestation of this frog species by this mite. Typical gross lesions were orange-colored skin vesicles approximately 1 mm in diameter, predominantly located on the ventrum and ventral hind limbs. The larval mites had ovoid bodies approximately 44 µm in length and 240 µm in width. Three of the frogs died, and three became free of mites and pathologic changes after approximately 28 wk of treatment with transcutaneous ivermectin and manual mite removal. The frogs remained free of mites at a 1-yr recheck.

CARDIORESPIRATORY EFFECTS OF MEDETOMIDINE–BUTORPHANOL, MEDETOMIDINE–BUTORPHANOL–DIAZEPAM, AND MEDETOMIDINE–BUTORPHANOL–KETAMINE IN CAPTIVE RED WOLVES (CANIS RUFUS)

Abstract Safe, effective, and reversible immobilization protocols are essential for the management of free-ranging red wolves (Canis rufus). Combinations using an α2-adrenoceptor agonist and ketamine have been shown to be effective for immobilization but are not reversible and can produce severe hypertension and prolonged or rough recoveries. To minimize hypertension and provide reversibility, 24 red wolves were immobilized using three medetomidine–butorphanol (MB) combinations without the use of ketamine in the initial injection. All wolves were administered medetomidine (0.04 mg/kg i.m.) and butorphanol (0.4 mg/kg i.m.). Seven wolves received no other immobilization agents (MB wolves), nine received diazepam (0.2 mg/kg i.v.) at the time they were instrumented (MBD wolves), and eight received ketamine (1 mg/kg i.v.) 30 min after instrumentation (MBK30 wolves). Physiologic parameters were monitored during immobilization. The heart rate was similar among the three groups for the first 30 min, and marked bradycardia was noted in one wolf from each group. Hypertension was observed initially in all three groups but was resolved within 10–30 min. The MBK30 wolves had significant elevations in heart rate and transient hypertension after intravenous ketamine administration. Most wolves had mild to moderate metabolic acidemia. Immobilizing drugs were antagonized in all wolves with atipamezole (0.2 mg/kg i.m.) and naloxone (0.02 mg/kg i.m.). The medetomidine-butorphanol-diazepam wolves were also given flumazenil (0.04 mg/kg i.v.). All wolves were standing within 12 min and were fully recovered within 17 min. Medetomamine-butorphanol and MBD combinations provided effective and reversible immobilization of red wolves without the sustained hypertension associated with the use of α2-adrenoceptor agonist–ketamine combinations. Delaying the administration of ketamine reduced its hypertensive effects.

COMPARISON OF THE CARDIORESPIRATORY EFFECTS OF MEDETOMIDINE–BUTORPHANOL–KETAMINE AND MEDETOMIDINE–BUTORPHANOL–MIDAZOLAM IN PATAS MONKEYS (ERYTHROCEBUS PATAS)

Abstract The cardiorespiratory effects, effectiveness, and reversibility of two injectable anesthetic combinations were compared in captive patas monkeys (Erythrocebus patas). Seven patas monkeys were hand-injected with medetomidine (40 μg/kg, i.m.), butorphanol (0.4 mg/kg, i.m.), and ketamine (3.0 mg/kg, i.m.), and seven were injected with the same dosages of medetomidine and butorphanol plus midazolam (0.3 mg/kg, i.m.). Heart rates decreased in monkeys in both treatment groups and were lower than those previously recorded in patas monkeys anesthetized with either ketamine or ketamine and isoflurane. Mean arterial pressures were highest in ketamine-treated monkeys but remained within normal limits for both groups. End tidal CO2 values increased gradually over time in both groups and were above physiologic norms after 20 min. Respiratory rates were similar between groups and remained constant throughout the procedures. Despite adequate ventilation parameters, initial low percent oxygen-hemoglobin saturation (SpO2) values were suggestive of severe hypoxemia. It was not clear whether these were accurate readings or an artifact of medetomidine-induced peripheral vasoconstriction. Oxygen supplementation restored SpO2 values to normal (>94%) in both groups. Both combinations effectively produced a state of light anesthesia, although spontaneous recoveries occurred after 30 min in three ketamine-treated monkeys. All monkeys were given i.m. atipamezole (0.2 mg/kg) and naloxone (0.02 mg/kg), whereas midazolam-treated monkeys also received flumazenil (0.02 mg/kg, i.v.), which resulted in faster (median recovery time = 5 min) and more complete recoveries in this group. Both combinations are safe to use when supplemented with oxygen, although the midazolam combination provided a longer anesthetic period and was more fully reversible.

CARDIOPULMONARY ASSESSMENT OF MEDETOMIDINE, KETAMINE, AND BUTORPHANOL ANESTHESIA IN CAPTIVE THOMSON'S GAZELLES (GAZELLA THOMSONI)

Abstract This investigation evaluated the cardiopulmonary effects of medetomidine, ketamine, and butorphanol anesthesia in captive juvenile Thomsons gazelles (Gazella thomsoni). Butorphanol was incorporated to reduce the dose of medetomidine necessary for immobilization and minimize medetomidine-induced adverse cardiovascular side effects. Medetomidine 40.1 ± 3.6 μg/kg, ketamine 4.9 ± 0.6 mg/kg, and butorphanol 0.40 ± 0.04 mg/kg were administered intramuscularly by hand injection to nine gazelles. Times to initial effect and recumbency were within 8 min postinjection. Cardiopulmonary status was monitored every 5 min by measuring heart rate, respiratory rate, indirect blood pressure, end-tidal CO2, and indirect oxygen-hemoglobin saturation by pulse oximetry. Venous blood gases were collected every 15 min postinjection. Oxygen saturations less than 90% in three gazelles suggested hypoxemia. Subsequent immobilized gazelles were supplemented with intranasal oxygen throughout the anesthetic period. Sustained bradycardia (<60 beats per minute, as compared with anesthetized domestic calves, sheep, and goats) was noted in eight of nine gazelles. Heart and respiratory rates and rectal temperatures decreased slightly, whereas systolic, mean, and diastolic blood pressure values were consistent over the anesthetic period. Mild elevations in end tidal CO2 and Pco2 suggested hypoventilation. Local lidocaine blocks were necessary to perform castrations in all seven of the gazelles undergoing the procedure. Return to sternal recumbency occurred within 7 min and return to standing occurred within 12 min after reversal with atipamezole (0.2 ± 0.03 mg/kg) and naloxone (0.02 ± 0.001 mg/kg). Medetomidine, ketamine, and butorphanol can be used to safely anesthetize Thomsons gazelles for routine, noninvasive procedures. More invasive procedures, such as castration, can be readily performed with the additional use of local anesthetics.

Suspected anaphylaxis to leuprolide acetate depot in two elf owls (Micrathene whitneyi).

Abstract Two adult female elf owls (Micrathene whitneyi) were treated with leuprolide acetate depot injections to prevent egg laying. The birds were treated for several years without complications. Several years into the treatment regimen, both birds died immediately after receiving an injection of leuprolide acetate. Remaining drug was analyzed, revealing 95.7% potency. We suspect that either an immediate Type 1 hypersensitivity reaction occurred or a contaminant was present, resulting in the fatalities of these elf owls. No reports of anaphylaxis to leuprolide acetate in birds were identified in the literature. Clinicians should be aware of the possibility of anaphylaxis when administering this medication to avian patients.

Teratoma in desert grassland whiptail lizards (Cnemidophorus uniparens).

Abstract The clinical, gross necropsy, and histopathology findings in two unrelated desert grassland whiptail lizards (Cnemidophorus uniparens) with teratoma are described. The desert grassland whiptail is a parthenogenic lizard species with a polyploid chromosomal complement. The chromosome composition of the teratomas from these lizards was not determined.

A SIMPLE METHOD OF PROVIDING INTERMITTENT POSITIVE-PRESSURE VENTILATION TO ETORPHINE-IMMOBILIZED ELEPHANTS (LOXODONTA AFRICANA) IN THE FIELD

Abstract Five African elephants (Loxodonta africana) were immobilized with etorphine in Waza National Park, Cameroon, for the purpose of deploying radio/satellite tracking collars. A portable ventilator constructed from two high-flow demand valves and the Y-piece of a large animal anesthesia circuit was used to provide intermittent positive-pressure ventilation with 100% oxygen. Oxygenation status improved dramatically in all five elephants. In one hypoxemic elephant, arterial PaO2 increased from 40 to 366 mm Hg. The results of this study demonstrate that both oxygenation and ventilation can be readily controlled in etorphine-immobilized elephants even under remote field conditions.

VESICULOBULLOUS SKIN REACTION TEMPORALLY RELATED TO FIROCOXIB TREATMENT IN A WHITE RHINOCEROS (CERATOTHERIUM SIMUM)

Abstract:  A 40 yr-old female white rhinoceros (Ceratotherium simum) suffered from chronic nail-bed abscesses. Due to worsening of clinical signs, the animals nonsteroidal anti-inflammatory treatment was switched to firocoxib. Approximately 7 days after this change, the animal developed multifocal vesicles and bullae along the lateral aspects of the thorax and abdomen, the dorsum, and the proximal limbs. Cytology and culture did not identify an infectious etiology. Histologically, the lesions consisted of a severe, subacute vesiculobullous dermatitis with intraepidermal to subepidermal clefting with areas of individual keratinocyte necrosis and minor neutrophilic epidermal infiltrates. These findings are similar to those seen in some drug reactions in people; therefore an adverse drug reaction to the firocoxib was suspected.

ORIGINAL ARTICLE: Medical and surgical management of reproductive neoplasia in two western lowland gorillas (Gorilla gorilla gorilla)

Background  Reports of female reproductive tract neoplasia are infrequent in great apes.

Malignant hypertension and retinopathy in a western lowland gorilla (Gorilla gorilla gorilla)

A 34‐year‐old western lowland gorilla presented with peracute blindness.