Objective—To determine the pharmacokinetics of
enrofloxacin after oral administration to captive elephants.
Animals—6 clinically normal adult Asian elephants
Procedure—Each elephant received a single dose of
enrofloxacin (2.5 mg/kg, PO). Three elephants
received their complete diet (pellets and grain) within
2 hours after enrofloxacin administration, whereas
the other 3 elephants received only hay within 6
hours after enrofloxacin administration. Serum concentrations
of enrofloxacin and ciprofloxacin were
measured by use of high-performance liquid
Results—Harmonic mean half-life after oral administration
was 18.4 hours for all elephants. Mean ± SD peak
serum concentration of enrofloxacin was 1.31 ±
0.40 µg/mL at 5.0 ± 4.2 hours after administration. Mean
area under the curve was 20.72 ± 4.25 (µg × h)/mL.
Conclusions and Clinical Relevance—Oral administration
of enrofloxacin to Asian elephants has a prolonged
elimination half-life, compared with the elimination
half-life for adult horses. In addition, potentially
therapeutic concentrations in elephants were
obtained when enrofloxacin was administered orally at
a dosage of 2.5 mg/kg. Analysis of these results suggests
that enrofloxacin administered with feed in the
manner described in this study could be a potentially
useful antimicrobial for use in treatment of captive
Asian elephants with infections attributable to organisms,
such as Bordetella spp, Escherichia coli,
Mycoplasma spp, Pasteurella spp, Haemophilus spp,
Salmonella spp, and Staphylococcus spp. (Am J Vet
OBJECTIVE To determine the pharmacokinetics of a single dose of meloxicam after IM and oral administration to healthy lesser flamingos (Phoeniconaias minor) by use of a population approach.
ANIMALS 16 healthy captive lesser flamingos between 1 and 4 years of age.
PROCEDURES A single dose of meloxicam (0.5 mg/kg) was administered IM to each bird, and blood samples were collected from birds at 3 (n = 13 birds), 2 (2), or 1 (1) selected point between 0 and 13 hours after administration, with samples collected from birds at each point. After a 15-day washout period, the same dose of meloxicam was administered PO via a red rubber tube and blood samples were collected as described for IM administration. Pharmacokinetic values were determined from plasma concentrations measured by high-performance liquid chromatography.
RESULTS Plasma drug concentrations after IM administration of meloxicam reached a mean ± SD maximum value of 6.01 ± 3.38 μg/mL. Mean area under the concentration-versus-time curve was 17.78 ± 2.79 μg•h/mL, and mean elimination half-life was 1.93 ± 0.32 hours. Plasma concentrations after oral administration reached a mean maximum value of 1.79 ± 0.33 μg/mL. Mean area under the curve was 22.16 ± 7.17 μg•h/mL, and mean elimination half-life was 6.05 ± 3.53 hours.
CONCLUSIONS AND CLINICAL RELEVANCE In lesser flamingos, oral administration of meloxicam resulted in higher bioavailability and a longer elimination half-life than did IM administration, but the maximum plasma concentration was low and may be insufficient to provide analgesia in flamingos. Conversely, IM administration achieved the desired plasma concentration but would require more frequent administration.
To establish a reference interval for glomerular filtration rate (GFR) determined by measuring serum clearance of a single IV dose of inulin in clinically normal cheetahs (Acinonyx jubatus) and compare serum symmetric dimethylarginine (SDMA) concentration in cheetahs with GFR.
33 cheetahs housed at 3 institutions.
A single bolus of inulin (3,000 mg/m2) was administered IV, and 5 serial blood samples were collected and analyzed for serum inulin concentration with the anthrone technique. The GFR was estimated with a modified slope-intercept method for the slow component of the serum concentration-versus-time curve. Blood urea nitrogen and serum creatinine concentrations were measured in samples obtained immediately prior to inulin administration, and serum SDMA concentration was measured in stored samples.
Mean ± SD measured GFR was 1.58 ± 0.39 mL/min/kg, and the calculated reference interval was 0.84 to 2.37 mL/min/kg. There were significant negative correlations between GFR and serum creatinine concentration (r = −0.499), BUN concentration (r = −0.592), and age (r = −0.463). Serum SDMA concentration was not significantly correlated with GFR (r = 0.385), BUN concentration (r = −0.281), or serum creatinine concentration (r = 0.165).
CONCLUSIONS AND CLINICAL RELEVANCE
A reference interval for GFR in clinically normal cheetahs was obtained. Further evaluation of animals with renal disease is needed to determine whether measuring serum clearance of a single IV dose of inulin is a reliable diagnostic test for early detection of renal disease in cheetahs.
To determine (1) if chemokine (C-X-C motif) ligand 1 (CXCL1), matrix metalloproteinase 8 (MMP8), interleukin-10 (IL-10), interferon-γ (IFN-γ), and tumor necrosis factor-α (TNF-α) can be detected in serum from Asian elephants, and (2) if their concentrations are significantly elevated in Mycobacterium tuberculosis (M.tb) culture–positive elephants compared to –negative elephants. CXCL1, MMP8, IL-10, IFN-γ, and TNF-α were recently identified as potential diagnostic biomarkers for pulmonary tuberculosis in experimental studies in animals and humans. Therefore, we hypothesized that they would be detectable and significantly elevated in M.tb culture–positive elephants compared to M.tb culture–negative elephants.
101 Asian elephant serum samples, including 91 samples from 6 M.tb-negative elephants and 10 samples from 5 M.tb-positive elephants (none of which exhibited clinical signs of disease). M.tb status was determined by trunk wash culture.
Commercially available ELISA kits were used to determine the concentrations of each biomarker in serum samples.
Biomarker concentrations were below the limit of detection for the assay in 100/101 (99%) samples for CXCL1, 98/101 (97%) samples for MMP8, 85/101 (84%) samples for IL-10, 75/101 (74%) samples for IFN-γ, and 45/101 (45%) samples for TNF-α. Multiple M.tb culture–positive elephants did not have detectable levels of any of the 5 biomarkers.
CXCL1, MMP8, IL-10, IFN-γ, and TNF-α were not elevated in M.tb culture–positive Asian elephants compared to M.tb culture–negative Asian elephants. This may be related to disease state (ie, clinically asymptomatic). More sensitive assays are needed to better understand the role of these biomarkers in M.tb infection in Asian elephants.
To examine potential relationships between ECG characteristics and echocardiographic measures of cardiac structure in chimpanzees (Pan troglodytes).
341 chimpanzees (175 males and 166 females) from 5 sanctuaries and 2 zoological collections.
Chimpanzees were anesthetized for routine health examinations between May 2011 and July 2017 as part of the International Primate Heart Project and, during the same anesthetic events, underwent 12-lead ECG and transthoracic echocardiographic assessments. Relationships between results for ECG and those for echocardiographic measures of atrial areas, left ventricular internal diameter in diastole (LVIDd), and mean left ventricular wall thicknesses (MLVWT) were assessed with correlational analysis, then multiple linear regression analyses were used to create hierarchical models to predict cardiac structure from ECG findings.
Findings indicated correlations (r = −0.231 to 0.310) between results for ECG variables and echocardiographic measures. The duration and amplitude of P waves in lead II had the strongest correlations with atrial areas. The Sokolow-Lyon criteria, QRS-complex duration, and R-wave amplitude in leads V6 and II had the strongest correlations with MLVWT, whereas the Sokolow-Lyon criteria, QRS-complex duration, and S-wave amplitude in leads V2 and V1 had the strongest correlations with LVIDd. However, the ECG predictive models that were generated only accounted for 17%, 7%, 11%, and 8% of the variance in the right atrial end-systolic area, left atrial end-systolic area, MLVWT, and LVIDd, respectively.
CONCLUSIONS AND CLINICAL RELEVANCE
Results indicated that relationships existed between ECG findings and cardiac morphology in the chimpanzees of the present study; however, further research is required to examine whether the predictive models generated can be modified to improve their clinical utility.
To comprehensively characterize cardiac structure and function, from infancy to adulthood, in male and female wild-born captive chimpanzees (Pan troglodytes) living in sanctuaries.
290 wild-born captive chimpanzees.
Physical and echocardiographic examinations were performed on anesthetized chimpanzees in 3 sanctuaries in Africa between October 2013 and May 2017. Results were evaluated across age groups and between sexes, and potential differences were assessed with multiple 1-way independent Kruskal-Wallis tests.
Results indicated that left ventricular diastolic and systolic function declined at a younger age in males than in females. Although differences in right ventricular diastolic function were not identified among age groups, right ventricular systolic function was lower in adult chimpanzees (> 12 years old), compared with subadult (8 to 12 years old) and juvenile (5 to 7 years old) chimpanzees. In addition, male subadult and adult chimpanzees had larger cardiac wall dimensions and chamber volumes than did their female counterparts.
CONCLUSIONS AND CLINICAL RELEVANCE
Results of the present study provided useful reference intervals for cardiac structure and function in captive chimpanzees categorized on the basis of age and sex; however, further research is warranted to examine isolated and combined impacts of blood pressure, age, body weight, and anesthetic agents on cardiac structure and function in chimpanzees.