Pharmacokinetic Profiles of Meloxicam and Sustained-release Buprenorphine in Prairie Dogs (Cynomys ludovicianus).

In this study, we evaluated the pharmacokinetic profiles of meloxicam and sustained-release (SR) buprenorphine in prairie dogs. The 4 treatment groups were: low-dose meloxicam (0.2 mg/kg SC), high-dose meloxicam (4 mg/kg SC), low-dose buprenorphine SR (0.9 mg/kg SC), and high-dose buprenorphine SR (1.2 mg/kg SC). The highest plasma concentrations occurred within 4 h of administration for both meloxicam treatment groups. The therapeutic range of meloxicam in prairie dogs is currently unknown. However, as compared with the therapeutic range documented in other species (0.39 - 0.91 µg/mL), the mean plasma concentration of meloxicam fell below the minimal therapeutic range prior to 24 h in the low-dose group but remained above therapeutic levels for more than 72 h in the high-dose group. These findings suggest that the current meloxicam dosing guidelines may be subtherapeutic for prairie dogs. The highest mean plasma concentration for buprenorphine SR occurred at the 24-h time point (0.0098 µg/mL) in the low-dose group and at the 8-h time point (0.015 µg/mL) for the high-dose group. Both dosages of buprenorphine SR maintained likely plasma therapeutic levels (0.001 µg/mL, based on previous rodent studies) beyond 72 h. Given the small scale of the study and sample size, statistical analysis was not performed. The only adverse reactions in this study were mild erythematous reactions at injection sites for buprenorphine SR.

Assessment of Domestic Goats as Models for Experimental and Natural Infection with the North American Isolate of Rickettsia slovaca.

Rickettsia slovaca is a tick-borne human pathogen that is associated with scalp eschars and neck lymphadenopathy known as tick-borne lymphadenopathy (TIBOLA) or Dermacentor-borne necrosis erythema and lymphadenopathy (DEBONEL). Originally, R. slovaca was described in Eastern Europe, but since recognition of its pathogenicity, human cases have been reported throughout Europe. European vertebrate reservoirs of R. slovaca remain unknown, but feral swine and domestic goats have been found infected or seropositive for this pathogen. Recently, a rickettsial pathogen identical to R. slovaca was identified in, and isolated from, the American dog tick, Dermacentor variabilis. In previous experimental studies, this organism was found infectious to guinea pigs and transovarially transmissible in ticks. In this study, domestic goats (Capra hircus) were experimentally inoculated with the North American isolate of this R. slovaca-like agent to assess their reservoir competence-the ability to acquire the pathogens and maintain transmission between infected and uninfected ticks. Goats were susceptible to infection as demonstrated by detection of the pathogen in skin biopsies and multiple internal tissues, but the only clinical sign of illness was transient fever noted in three out of four goats, and reactive lymphoid hyperplasia. On average, less than 5% of uninfected ticks acquired the pathogen while feeding upon infected goats. Although domestic goats are susceptible to the newly described North American isolate of R. slovaca, they are likely to play a minor role in the natural transmission cycle of this pathogen. Our results suggest that goats do not propagate the North American isolate of R. slovaca in peridomestic environments and clinical diagnosis of infection could be difficult due to the brevity and mildness of clinical signs. Further research is needed to elucidate the natural transmission cycle of R. slovaca both in Europe and North America, as well as to identify a more suitable laboratory model.