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
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.
Objective—To determine the pharmacokinetic properties of 1 IM injection of ceftiofur crystalline-free acid (CCFA) in American black ducks (Anas rubripes).
Animals—20 adult American black ducks (6 in a preliminary experiment and 14 in a primary experiment).
Procedures—Dose and route of administration of CCFA for the primary experiment were determined in a preliminary experiment. In the primary experiment, CCFA (10 mg/kg, IM) was administered to ducks. Ducks were allocated into 2 groups, and blood samples were obtained 0.25, 0.5, 1, 2, 4, 8, 12, 48, 96, 144, 192, and 240 hours or 0.25, 0.5, 1, 2, 4, 8, 24, 72, 120, 168, and 216 hours after administration of CCFA. Plasma concentrations of ceftiofur free acid equivalents (CFAEs) were determined by use of high-performance liquid chromatography. Data were evaluated by use of a naive pooled-data approach.
Results—The area under the plasma concentration versus time curve from 0 hours to infinity was 783 h•μg/mL, maximum plasma concentration observed was 13.1 μg/mL, time to maximum plasma concentration observed was 24 hours, terminal phase half-life was 32.0 hours, time that concentrations of CFAEs were higher than the minimum inhibitory concentration (1.0 μg/mL) for many pathogens of birds was 123 hours, and time that concentrations of CFAEs were higher than the target plasma concentration (4.0 μg/mL) was 73.3 hours.
Conclusions and Clinical Relevance—On the basis of the time that CFAE concentrations were higher than the target plasma concentration, a dosing interval of 3 days can be recommended for future multidose CCFA studies.