Treatment of Bovine Leptospirosis with Enrofloxacin HCl 2H(2)O (Enro-C): A Clinical Trial

SIMPLE SUMMARY: Unlike standard enrofloxacin, its crystal solvate enrofloxacin HCl-2H(2)O (enro-C) exhibits favorable pharmacokinetics and PK/PD ratios compatible with its use as a treatment during the clinical phase of leptospirosis in cattle. Hence, a clinical trial was conducted in cattle located either in the highlands (HL) or the tropics (TL). A high dose of 15 mg/kg day IM of enro-C administered over 5 days was compared against the conventional treatment with streptomycin/penicillin-G. The cows treated with enro-C became PCR negative: 87.5% and 78.94% on day 5, and 92.85% and 94.73% on day 28 (in the HL and TL, respectively). For streptomycin/penicillin-G, the same values were 65.45% and 70.90% on day 5 and 73.68% in both scenarios on day 28. In both groups, the microagglutination titers dropped on day 28, and gestation rates were statistically indistinguishable between the groups. This is the first report of successful treatment with fluoroquinolone in treating bovine leptospirosis. ABSTRACT: Pharmacokinetics/pharmacodynamics ratios of enrofloxacin HCl-2H(2)O (enro-C) in cows to treat bovine leptospirosis prompted this clinical trial in the highlands (HL) and the tropics (TL) in Mexico. In the HL, 111 Holstein-Friesian cows were included and 38 F1 Zebu–Holstein/Friesians in the TL. Affected cows were randomly divided into two treatment groups, both in the HL and TL. PCR and MAT tests were performed before and after treatment. Treatments in both groups were administered for 5 d with either IM injections of enro-C or streptomycin/penicillin-G. Reproductive performance data were gathered for 90 d. The cows treated with enro-C became PCR negative: 87.5% and 78.94% on day 5, 92.85% and 94.73% on day 28 (in the HL and TL, respectively). For streptomycin/penicillin-G, the same values were 65.45% and 70.90% on day 5, and 73.68% twice on day 28 in the HL and TL, respectively. In both groups and geographical settings, the MAT titers dropped on day 28 but remained above reference values usually considered negative. The gestation rates were: 86.53% and 79.06% and 88.88% and 87.5% for the HL and TL, either with enro-C or streptomycin/penicillin-G, respectively. This is the first report of successful treatment with a fluoroquinolone derivative in treating bovine leptospirosis with a high bacteriological cure rate.