ABSTRACT
The objective of this study was to determine the pharmacokinetics of two orally administered doses of tramadol (1 mg/kg and 5 mg/kg) and its metabolite, O-desmethyltramadol (M1) in giant tortoises (Chelonoidis vandenburghi, Chelonoidis vicina). Eleven giant tortoises (C. vandenburghi, C. vicina) received two randomly assigned, oral doses of tramadol (either 1 mg/kg or 5 mg/kg), with a washout period of 3 wk between each dose. The half-life (t½) of orally administered tramadol at 1 mg/kg and 5 mg/kg was 11.9 ± 4.6 h and 13.2 ± 6.1 h, respectively. After oral administration of tramadol at 1 mg/kg and 5 mg/kg, the maximum concentration (Cmax) was 125 ± 69 ng/ml and 518 ± 411 ng/ml, respectively. There were not enough data points to determine pharmacokinetic (PK) parameters for the M1 metabolite from either dose. Tramadol administered orally to giant tortoises at both doses provided measurable plasma concentrations of tramadol for approximately 48 h with occasional transient sedation. Oral tramadol at 5 mg/kg, on average, achieves concentrations of >100 ng/ml, the reported human therapeutic threshold, for 24 h. Based on the low levels of M1 seen in this study, M1 may not be a major metabolite in this taxon.
Subject(s)
Tramadol , Turtles , Animals , Administration, Oral , Analgesics, Opioid , Area Under Curve , Half-Life , Tramadol/pharmacokinetics , Tramadol/analogs & derivatives , Turtles/metabolismABSTRACT
Kirk's dik-diks (Madoqua kirkii) are the most common dik-dik species managed in North American zoological institutions, but their numbers are declining at a concerning rate, with less than 40 individuals currently housed in accredited institutions. This retrospective study reports the causes of mortality in Kirk's dik-diks in North American zoological institutions from 1988 to 2019. Out of 15 institutions accredited by the Association of Zoos and Aquariums (AZA) currently housing Kirk's dik-diks, nine contributed to this study (60% participation). Eighty-four necropsy records were reviewed to determine the primary affected body system and etiological cause of death across and within age categories. Neonatal death (prior to 1 mon of age) was most common (38.1%), followed by death in adults (29.8%), geriatric animals (19.0%), and juveniles (13.1%). As a whole population, causes of death by body system were multisystemic (47.6%), musculoskeletal (15.5%), respiratory (8.3%), and digestive (8.3%). Neonatal complications accounted for 50.0% of all deaths in animals prior to 1 mon of age. In juveniles, a nutritional cause of death was most common (27.3%) and significantly higher compared to measures of this cause within other age categories. In adults, metabolic etiologies and trauma each accounted for 28.0% of deaths. Degenerative etiologies were most common in geriatric individuals, representing 31.3% of the deaths. Death from infectious disease was found across all ages, representing 11.9% of all mortalities. Results from this study provide a baseline reference for this species and may aid clinicians in decision-making as it relates to the medical care and management of this species during different life stages.
Subject(s)
Antelopes , Animals , North America , Retrospective StudiesABSTRACT
A 1-y-old female southern tamandua (Tamandua tetradactyla) presented with vomiting, hyporexia, and neurologic signs. Magnetic resonance imaging revealed contrast-enhancing material within the lateral and fourth ventricles and a T2 hyperintense cerebellar lesion, consistent with meningoencephalitis. The tamandua rapidly declined and was euthanatized. On gross postmortem exam, the tamandua had diffusely injected leptomeninges, opaque fluid in the fourth ventricle, and subdural brainstem and spinal cord hemorrhage. Histologically, there was regionally hemorrhagic and multifocal fibrinosuppurative meningoencephalomyelitis, ventriculitis, choroid plexitis, cerebellar folia necrosis, ependymitis, radiculoneuritis, and abundant intralesional gram-positive cocci. Streptococcus equi ssp. zooepidemicus was cultured from brain, cardiac blood clot, and multiple samples of horsemeat collected from the animal's diet. This is the first report of streptococcal meningoencephalomyelitis in a southern tamandua. The route of infection was likely gastrointestinal inoculation, which may have implications for the routine practice of feeding diets containing raw meat to insectivores.
