Pharmacokinetics of intravenous clindamycin phosphate in captive Bennett's wallabies (Macropus rufogriseus).

This study was designed to investigate the pharmacokinetics of clindamycin, a lincosamide antibiotic, in Bennett's wallabies. The pharmacokinetic properties of a single intravenous (IV) dose of clindamycin were determined in six wallabies. A single 20-min IV infusion of 20 mg/kg of clindamycin was administered, followed by blood collection prior to, and up to 12 hr after clindamycin administration. Plasma clindamycin concentrations were determined by high-pressure liquid chromatography (HPLC) with ultraviolet (UV) detection. Pharmacokinetic variables were calculated using a two-compartment model with first order elimination which best fit the data. The mean volume of distribution at steady-state, distribution half-life, and elimination half-life were 898.25 ml/kg, 0.16 hr, 1.79 hr, respectively. No adverse effects were noted after IV administration.

Initial Case Reports of Cancer in Naked Mole-rats (Heterocephalus glaber).

Naked mole-rats (NMRs;Heterocephalus glaber) are highly adapted, eusocial rodents renowned for their extreme longevity and resistance to cancer. Because cancer has not been formally described in this species, NMRs have been increasingly utilized as an animal model in aging and cancer research. We previously reported the occurrence of several age-related diseases, including putative pre-neoplastic lesions, in zoo-housed NMR colonies. Here, we report for the first time 2 cases of cancer in zoo-housed NMRs. In Case No. 1, we observed a subcutaneous mass in the axillary region of a 22-year-old male NMR, with histologic, immunohistochemical (pancytokeratin positive, rare p63 immunolabeling, and smooth muscle actin negative), and ultrastructural characteristics of an adenocarcinoma possibly of mammary or salivary origin. In Case No. 2, we observed a densely cellular, poorly demarcated gastric mass of polygonal cells arranged in nests with positive immunolabeling for synaptophysin and chromogranin indicative of a neuroendocrine carcinoma in an approximately 20-year-old male NMR. We also include a brief discussion of other proliferative growths and pre-cancerous lesions diagnosed in 1 zoo colony. Although these case reports do not alter the longstanding observation of cancer resistance, they do raise questions about the scope of cancer resistance and the interpretation of biomedical studies in this model. These reports also highlight the benefit of long-term disease investigations in zoo-housed populations to better understand naturally occurring disease processes in species used as models in biomedical research.

Meloxicam pharmacokinetics using nonlinear mixed-effects modeling in ferrets after single subcutaneous administration.

This study was designed to investigate the pharmacokinetics of meloxicam, an oxicam class, nonsteroidal anti-inflammatory drug (NSAID), in ferrets. We determined the pharmacokinetic properties of a single subcutaneous dose of meloxicam (0.2 mg/kg) in nine male and nine female ferrets. Blood samples were collected by venipuncture of the cranial vena cava into heparinized syringes. Plasma meloxicam concentrations were determined by high-pressure liquid chromatography (HPLC). Pharmacokinetic variables were calculated using nonlinear mixed-effects modeling to take advantage of the population-based sampling scheme and to minimize sample volume collected per animal. Maximum plasma concentration, volume of distribution per absorption, and elimination half-life were 0.663 µg/mL, 0.21 L, and 11.4 h, respectively, for females and 0.920 µg/mL, 0.35 L, and 17.8 h, respectively, for males. Significant differences were found in each of the above parameters between male and female ferrets. Systemic clearance per absorption was not affected by gender and was 13.4 mL/h. Analgesic efficacy was not evaluated, but plasma meloxicam concentrations achieved in these animals are considered effective in other species. Sex differences in the pharmacokinetic behavior of meloxicam should be taken into consideration when treating ferrets.

Microbiology of the external ear canal in six African elephants (Loxodonta africana).

Samples collected from both external ear canals of six adult female African elephants (Loxodonta africana) were cultured for fungi, yeasts and aerobic and anaerobic bacteria. All the samples produced heavy growths of several aerobic bacteria, but anaerobic bacteria were rare and no fungi or yeasts were isolated. The most common bacterium isolated was Staphylococcus epidermidis, which was cultured from 11 of the 12 ears. Acinetobacter calcoaceticus lwoffi, alpha-haemolytic Streptococcus and Corynebacterium species, and Aeromonas caviae were all isolated from at least six of the 12 ears.

Development of a perceived exertion scale for dogs using selected physiologic parameters.

OBJECTIVE: To develop a perceived exertion scale for dogs exercising on a treadmill and to assess intra- and inter-observer variability. MATERIALS AND METHODS: Fifteen healthy client-owned dogs participated in paired exercise trials. Measurements of lactate, glucose, heart rate, temperature, respiratory rate and regional tissue oximetry were obtained before, during and after exercise. Perceived exertion scale scores were recorded during exercise and using video recordings to evaluate inter-observer variability. Correlations were evaluated using the Spearman's non-parametric method. RESULTS: Thirteen dogs completed both trials. Dogs walked or trotted on the treadmill with an average perceived exertion score of 2 in both trials. Holter heart rate was positively correlated with perceived exertion scale scores from all observers for both trials. In trial 1, plasma glucose decreased in association with increase in perceived exertion and, in trial 2, cutaneous oximetry decreased, respiratory rate increased and temperature increased with increases on the perceived exertion scale. Inter-observer perceived exertion scale scores were positively correlated in both trials. There was no intra-observer variability between trials. CLINICAL SIGNIFICANCE: The perceived exertion scale correlated with the measured physiologic parameters in dogs exercising at mild to moderate intensity. The perceived exertion scale was consistent and repeatable but larger study numbers and further validation are needed before it can be widely applied.

Prothrombin time and activated partial thromboplastin time using a point-of-care analyser (Abaxis VSpro®) in Bennett's wallabies (Macropus rufogriseus).

There are few reports of coagulation times in marsupial species. Blood samples collected from 14 Bennett's wallabies (Macropus rufogriseus) under anaesthesia during routine health assessments were analysed for prothrombin time (PT) and activated partial thromboplastin time (aPTT) using a point-of-care analyser (POC) (Abaxis VSPro®). The wallabies had an aPTT mean of 78.09 s and median of 78.1 s. The PT for all wallabies was greater than 35 s, exceeding the longest time measured on the POC. Although PT was significantly longer, aPTT was similar to the manufacturer's domestic canine reference range.

Congenital peritoneopericardial diaphragmatic hernia in an alpaca.

An adult alpaca was presented because of abdominal pain and was diagnosed with an intestinal obstruction. The putative diagnosis at surgery was an intestinal obstruction caused by peritonitis and intra-abdominal adhesions. The cause of the inflammation was not determined at that time. The alpaca died soon after surgery from post-surgical complications and a peritoneopericardial diaphragmatic hernia that was not diagnosed until necropsy.