Effect of probenecid on kinetics of enrofloxacin in lactating goats after subcutaneous administration.

A comparative pharmacokinetic study of enrofloxacin (5 mg/kg, sc) was conducted in probenecid-pretreated (70 mg/kg, orally 1.5 h prior to enrofloxacin administration) lactating goats to assess the effect of probenecid on the kinetics of enrofloxacin. Concentration of enrofloxacin in plasma, milk and urine was estimated by microbiological assay using Escherichia coli (ATCC 25922). Minimum detection level of enrofloxacin was 0.01 microg/ml. The plasma log concentration versus time curve showed monophasic pattern and followed one compartment open model. Plasma drug concentration was significantly higher during 1-2 h in probenecid-pretreated group. Significantly higher drug concentration in milk was noted at most of the time points, while significantly lower urine drug concentration (0.083-1 h and 5-12 h) were obtained in probenecid-pretreated group. The kinetic parameters (A, B and 3) were significantly higher, while t(1/2)beta, MRT and Vd(area) were significantly lower in probenecid-pretreated group. Probenecid pretreatment decreased the urinary excretion of enrofloxacin, whereas enhanced excretion in milk which could be useful in cases of affections of udder in goats.

Urolitíase em caprinos e ovinos / Urolithiasis in sheep and goats

A urolitíase é uma doença freqüente no semi-árido em ovinos e caprinos alimentados com grãos, principalmente quando a relação Ca:P não é corrigida e são utilizadas grandes quantidades de concentrado. De 28 ovinos com urolitíase atendidos no Hospital Veterinário da UFCG, 19 morreram e 9 receberam alta, dos 15 caprinos 12 morreram e 3 receberam alta. As alterações mais freqüentes foi presença de cálculos na uretra e bexiga, uretrite hemorrágica difusa severa, uretrite purulenta, ruptura de uretra com presença de urina no tecido subcutâneo, cistite hemorrágica necrosante, ruptura de bexiga, hidronefrose, nefrite necrosante difusa, abscesso renal, pielonefrite, hemorragia renal e ruptura renal. A gravidade das lesões observadas justifica a alta letalidade apesar dos tratamentos medicamentosos e cirúrgicos. A medida preventiva mais importante é a correção dos níveis de Ca e P. Recomenda-se, também, a administração de volumosos em boa quantidade e qualidade e, nos casos em que a quantidade de concentrados seja superior a 1,5 por cento do peso vivo, a administração de cloreto de amônia a 1 por cento no concentrado e a administração de cloreto de sódio em concentrações de 0,5 até 4 por cento. Deve ser administrada água de boa qualidade à vontade. É necessário abolir a prática, extremamente utilizada em caprinos e ovinos, de administrar sal mineral em animais alimentados com grãos e subprodutos dos mesmos.

Urolithiasis is a common disease in the Brazilian semiarid in rams and bucks fed with grains, mainly with low C:P ratio. From 28 rams with urolithiasis sent to the Veterinary Hospital of the Federal University of Campina Grande, Paraíba, 19 died and 9 survived, and from the bucks, 13 died and 3 survived At necropsy the main lesions were presence of calculi in the urethra and urinary bladder, diffuse purulent urethritis, hemorrhagic necrotizing urethritis, rupture of the urethra with presence of urine in the subcutaneous tissue, hydronephrosis, urinary bladder rupture, necrotizing diffuse nephritis, pyelonephritis, renal hemorrhage, and renal rupture. The severity of the lesions is responsible for the high case fatality rate despite medical and chirurgic treatment. The most important preventive measure is the correction of the Ca:P ratio to at least 2:1. The administration of good quality roughage in the food is also necessary. In cases in which the amount of concentrate food is higher than 1.5 percent live weight, the addition of 1 percent ammonium chloride and 0.5-4 percent of sodium chloride in the diet could be also necessary. Water had to be offered ad libitum. It is necessary to abolish the use of ad libitum mineral supplementation in sheep and goats fed grains or their byproducts.