Goats elimination

Endosulfan residues are rapidly eliminated from tissues as suggested by a half-life of approximately 7 days estimated in a 14-day oral study in female rats (Dorough et al. 1978). Rapid elimination was also observed in a 28-day study in goats in which half-lives between 1.1 and 3.1 days were estimated for endosulfan residues in various organs and tissues (Indraningsih et al. 1993). 

When tiamulin was given to farm animals by injection, mean elimination half-lives were 3, 3.3, 4.6, and 3.6 h in cattle, buffalo, sheep, and goats, respectively (260, 261). Tiamulin could not be detected at 24 h posttreatment. 

Absorption of fenbendazole is slow in ruminants but more rapid in monogastric animals. Maximum concentrations in blood are achieved at about 8 h in rats and rabbits, 24 h in dogs, and 2-3 days in sheep. Elimination of fenbendazole is predominantly by the fecal route. The metabolic pathway of fenbendazole is similar in rats, rabbits, dogs, sheep, cattle, goats, and chickens. It is rapidly metabolized to fenbendazole sulfoxide (oxfendazole), fenbendazole sulfone, fenbendazole 2-aminosulfone, and other minor metabolites detected in plasma. 

In some cases, the same disease states exert no effect on drug pharmacokinetics as with amoxycillin and chloramphenicol in calves, and ampicillin and sulfamethazole in goats. Although feverish pigs show reduced elimination half-lives when oxytetracycline is given orally, there is no apparent effect after intravenous administration, which suggests an effect on gastrointestinal absorption (39). 

Similar considerations can also be made for animals of different gender. Antipyrine plasma elimination, for example, in rats and cattle show gender differences that, to some extent, cannot be mediated by sex hormones. In contrast, clearance of antipyrine and sulfamethazine in female dwarf goats markedly decreases following implantation of the anabolic steroid trenbolone (64). 

The pesticide has also been used to control exoparasites on livestock (cattle, sheep, and goats) [20]. Toxaphene is highly toxic to fish. For a short period in the 1960s, it was used as a piscicide to eliminate undesired fish species in lakes prior to the release of commercially attractive fish species. Saleh reported about 817 registered products containing toxaphene in a concentration of 1 % to 80% [3]. Toxaphene was marketed as emulsifiable concentrates, powders, granules, and baits [3]. 

Rapid placental transfer was reported in goats and mice. In goats, the fetal plasma levels approached 50% of maternal values within 10 min of the mother receiving an intravenous dose, and the fetal/maternal plasma ratio remained at 0.5 for 1 h, whereas ratios in the liver, kidney, heart, and brain all approached 1 and showed a marked effect on fetal heart rate. In pregnant mice, radiolabeled chlorpromazine rapidly crossed the placenta and accumulated in the eyes of both fetuses and mothers. Marked radioactivity remained in tissues of the eye for 5 months after the drug had been eliminated from other tissues. 

Fluoroacetate is rapidly absorbed by the gastrointestinal tract but not well absorbed dermally. Fluoroacetate is converted to the ultimate toxicant, fluorocitrate. Fluoroacetate is distributed to lipid-rich organs, such as the liver, brain, and kidneys. Fluoroacetate is primarily eliminated through urine. Up to 50% of the fluoroacetate is excreted unchanged in the urine by 72 h following administration. The kinetic half-life for sodium fluoroacetate is species dependent. Reported half-lives in rabbits, goats, and sheep are 1.1, 4-7, and 13.3 h, respectively. 

The tetracyclines, apart from doxycycline and minocycline, are slowly eliminated by renal excretion (glomerular filtration). Their slow elimination can be attributed to enterohepatic circulation whereby drug excreted by the liver in bile is reabsorbed from the intestine. The half-life of oxytetracycline differs widely between animal species goat (3.4 h), cattle (4.0 h), sheep (5.2 h), dog (6.0 h), pig (6.0 h), donkey (6.5 h), horse (9.6 h), and red-necked wallaby (.Macropus rufogriseus) (11.4 h). Doxycycline, unlike other tetracyclines, is eliminated by biliary excretion and diffusion into the intestine. The half-life of doxycycline is relatively short in dogs (7.0 h) and cats (4.6 h) compared with human beings (16 h). The half-life of doxycycline in chickens (4.8 h) is shorter than in turkeys (10 h) (Santos et al, 1996). Minocycline is mainly eliminated by hepatic metabolism. 

I be to xico kinetics of PBO has also been studied in the goat and hen following daily oral administration for 5 days at a dose level of 10 or 100 mg kg diet. In Ihe goal the (Jose was excreted mainly in the urine (79-1 and 72.6%, respectively) with the remainder being found in the faeces. Milk was a minor route of elimination, accounting for less than 1% of the total dose (Selim, I995aj. 

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