Effect of injection site on alfaxalone-induced sedation in ball pythons (Python regius).

OBJECTIVES: To evaluate the sedative and cardiorespiratory effects of alfaxalone in ball pythons following subcutaneous administration in the cranial versus caudal third of the body. MATERIALS AND METHODS: In a prospective, randomised, blinded, complete crossover study, eight ball pythons ( Python regius ) received alfaxalone in the cranial or caudal third of the body. Sedative and cardiorespiratory parameters were recorded. RESULTS: Administration of alfaxalone in the cranial third of the body resulted in significantly deeper and longer sedation compared with administration in the caudal third of the body. Righting reflex was lost in five of eight snakes following cranial injection compared with one of eight snakes after caudal injection. Jaw tone was lost in all snakes following cranial injection and intubation was successfully performed in seven. In contrast, snakes did not lose jaw tone and intubation was not possible following caudal injection. Heart rate and respiratory rate were significantly decreased following administration of alfaxalone in the cranial third of the body. CLINICAL SIGNIFICANCE: Administration of drugs that undergo hepatic metabolism or excretion should not be performed in the caudal third of the body in snakes, because it can result in significantly reduced drug efficacy. A hepatic first-pass effect is assumed to be the most likely underlying cause for the observed effect because part of the venous return from the caudal body flows directly to the liver.

Diagnosis and management of oviductal disease in three red-eared slider turtles (Trachemys scripta elegans).

Three mature, female, red-eared slider turtles (Trachemys scripta elegans) were individually, and separately, diagnosed with different forms of oviductal disease. Case 1 presented with acute cloacal bleeding and was diagnosed with acute oviductal rupture and ectopic eggs in the coelom. Case 2 presented for repeated scratching in the direction of the cloaca and was diagnosed with chronic oviductal impaction and coelomitis. Both cases were treated successfully by endoscopy-assisted complete ovariosalpingectomy via a bilateral prefemoral approach. Case 3 presented with a reduced appetite and signs of nesting behaviour and was diagnosed with obstructive dystocia associated with bacterial salpingitis. Successful treatment consisted of transcloacal egg removal and systemic antibiotics. Complete recovery was achieved in all three turtles, which remained disease-free 23 to 33 months later. Oviductal disease can present with a variety of clinical signs, and an accurate diagnosis can be made based on a thorough history, physical examination and appropriate diagnostic techniques.

Comparative efficacy of tricaine methanesulfonate and clove oil for use as anesthetics in red pacu (Piaractus brachypomus).

OBJECTIVE: To compare the anesthetic efficacy and physiologic changes associated with exposure to tricaine methanesulfonate and clove oil (100% eugenol). ANIMALS: 15 adult cultured red pacu (Piaractus brachypomus). PROCEDURE: Fish were exposed to each of 6 anesthetic concentrations in a within-subjects complete crossover design. Stages of anesthesia and recovery were measured, and physiologic data were collected before and during anesthesia. RESULTS: Interval to induction was more rapid and recovery more prolonged in fish exposed to eugenol, compared with those exposed to tricaine methanesulfonate. The margin of safety for eugenol was narrow, because at the highest concentration, most fish required resuscitation. Mixed venous-arterial PO2 consistently decreased with anesthesia, while PCO2 consistently increased with anesthesia in all fish regardless of anesthetic agent. The increase in PCO2 was accompanied by a decrease in pH, presumably secondary to respiratory acidosis. Anesthesia was associated with increased blood glucose, potassium, and sodium concentrations as well as Hct and hemoglobin. Fish anesthetized with eugenol were more likely to react to a hypodermic needle puncture than fish anesthetized with tricaine methanesulfonate. CONCLUSIONS AND CLINICAL RELEVANCE: Anesthesia induced with tricaine methanesulfonate or eugenol contributes to hypoxemia, hypercapnia, respiratory acidosis, and hyperglycemia in red pacu. Similar to tricaine methanesulfonate, eugenol appears to be an effective immobilization compound, but eugenol is characterized by more rapid induction, prolonged recovery, and a narrow margin of safety. Care must be taken when using high concentrations of eugenol for induction, because ventilatory failure may occur rapidly. In addition, analgesic properties of eugenol are unknown.

Cholesterol granulomas in three meerkats (Suricata suricatta).

Cholesterol granulomas are uncommon pathologic lesions in animals, although they are important intracranial tumors in humans. This report describes cholesterol granulomas associated with multiple organ systems of three captive meerkats. In the most severe case, meerkat No. 1, the pathologic behavior of the cholesterol granuloma was unique in that it appeared to locally invade the cerebrum and calvarium, possibly contributing to neurological deficits observed antemortem. A review of other meerkat necropsies revealed incidental, asymptomatic cholesterol granulomas in organs of two other individuals, meerkat Nos. 2 and 3. Histologically, all lesions were composed of cholesterol clefts admixed with large, foamy macrophages containing hemosiderin, multinucleated giant cells, lymphocytes, plasma cells, and foci of mineralization. Hypercholesterolemia was documented in two of the three meerkats.

Cardiorespiratory effects of four alpha2-adrenoceptor agonist-ketamine combinations in captive red wolves.

OBJECTIVE: To evaluate the cardiopulmonary effects of immobilizing doses of xylazine-ketamine (XK), medetomidine-ketamine (MK), medetomidine-ketamine-acepromazine (MKA), and medetomidine-butorphanol-ketamine (MBK) in captive red wolves. DESIGN: Prospective study. ANIMALS: 32 adult captive red wolves. PROCEDURE: Wolves were randomly assigned to 1 of 4 treatment groups: XK, MK, MKA, or MBK. Physiologic variables measured included heart rate, blood pressure, respiratory rate, tidal volume, oxygen-hemoglobin saturation (Spo2), end-tidal CO2, arterial blood gases, and rectal temperature. Induction time, muscle relaxation, and quality of recovery were assessed. RESULTS: Heart rates were lower in wolves in the MBK group than for the other groups. All 4 drug combinations induced considerable hypertension, with diastolic pressures exceeding 116 mm Hg. Blood pressure was lowest in wolves receiving the MBK combination. Respiratory rate was significantly higher in wolves receiving XK, MK, and MKA. Tidal volumes were similar for all groups. Wolves receiving XK, MK, and MKA were well-oxygenated throughout the procedure (SPo2 > 93%), whereas those receiving MBK were moderately hypoxemic (87% < Spo2 < 93%) during the first 20 minutes of the procedure. Hyperthermia was detected initially following induction in all groups. CONCLUSIONS AND CLINICAL RELEVANCE: The alpha2-adrenoceptor agonist-ketamine combinations provide rapid reversible anesthesia for red wolves but cause severe sustained hypertension. Such an adverse effect puts animals at risk for development of cerebral encephalopathy, retinal hemorrhage, pulmonary edema, and myocardial failure. Although the MBK combination offers some advantages over the others, it is advised that further protocol refinements be made to minimize risks associated with acute hypertension.

Trombiculid mites (Hannemania sp.) in canyon tree frogs (Hyla arenicolor).

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 microm in length and 240 microm 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.

Evaluation of epidural morphine for postoperative analgesia in ferrets (Mustela putorius furo).

We evaluated the analgesic efficacy of epidural morphine for relieving postoperative pain in domestic ferrets by evaluating behavior and fecal cortisol concentrations. The 12 laboratory-reared, intact, female, domestic ferrets were anesthetized then underwent ovariohysterectomy and bilateral anal sacculectomy. Using a double-blind procedure, we provided epidural morphine (0.1 mg/kg) to six ferrets and epidural saline (0.1 mL/ferret) to the remaining animals prior to surgery. Compared to the animals that received saline, the morphine-treated ferrets were more likely to have attenuated pain responses, and they returned more rapidly to preoperative behavior. Although fecal cortisol concentrations during the first 24 h after surgery increased in all animals, the increase was statistically significant only in the ferrets that received saline epidurals. These data suggest that morphine epidurals administered to ferrets prior to surgery may attenuate both the physiologic and behavioral manifestations of surgically induced pain.

Androgenic influences on body size and composition of adult rhesus monkeys.

The effects of daily treatment with testosterone propionate (TP, 2 mg/kg) and dihydrotestosterone propionate (DHTP, 2 mg/kg) were examined in rhesus monkeys in three experiments. In experiments 1 and 2, males and females gonadectomized in infancy, and female pseudohermaphrodites produced by prenatal exposure to TP or DHTP and gonadectomized postpubertally, were studied in conjunction with intact males (IM). The IM group was heavier in adulthood than the three gonadectomized groups, which did not differ in body weight from each other. Genetic males had greater crown-rump length than genetic females. Treatment of the gonadectomized groups with TP produced large increases in body mass (averaging approximately 50%) that were attributable to accretion of lean tissue. This effect did not differ significantly between males and females. In experiment 3, additional groups of males that had been castrated as infants were given daily injections with DHTP or oil. The DHTP treatment resulted in increases in body size that were not different from those seen following TP treatment. When TP and DHPT treatments were discontinued, body weights and dimensions reverted to base-line values. Increased body size induced by TP and DHTP was accomplished without reliable increases in food intake. Because testosterone (T) is metabolized to dihydrotestosterone (DHT), while DHT cannot be converted to T, these results show that both T and DHT are effective anabolic hormones in rhesus.

The effects of isosexual rearing on adult sexual behavior in captive male rhesus macaques.

The sexual competence of males reared only with other males (isosexually reared) was compared to the sexual competence of males reared in mixed-sex peer groups (heterosexually reared). All subjects were pair-tested with the same 11 females. Isosexually reared males tended to be less sexually active than heterosexually reared males, but the differences were not pronounced. Heterosexually reared males took less time to ejaculate than isosexually reared males, but their ejaculatory frequencies were comparable. Among one peer group of isosexually reared males, their level of sexual competence conformed with their dominance ranks when immature. These results suggest that growing up with female peers is not a prerequisite for the expression of adult sexual behavior among male rhesus macaques and that adult male sexual behavior may be influenced by relative dominance status when immature.