Oral doxycycline pharmacokinetics: Lambs in comparison with sheep

Abstract

The pharmacokinetics of doxycycline was investigated in lactating sheep and lambs after oral administration at a dose of 10 mg/kg. Concentrations in plasma and milk were assayed with HPLC‐PDA analysis. Doxycycline penetrates into the milk, and levels (0.38 ± 0.21 μg/ml) were found 0.5 hr after the treatment. The results suggest that the lambs can be exposed to doxycycline by suckling milk from their treated mothers. Population pharmacokinetic analysis showed a positive relationship between age, which reflects the stage of development of rumen function, and clearance. Possible explanations for the observed differences include the undeveloped rumen in lambs, the differences in the feed and liver function as evidenced by the blood biochemical parameters aspartate aminotransferase (AST) and alanine aminotransferase (ALT), which were significantly lower in lambs (62.67 ± 27.83 U/L and 8.50 ± 6.80 U/L) than in sheep (114.33 ± 20.77 U/L and 18.00 ± 3.16 U/L).

Comparative Study of the Use of Doxycycline and Oxytetracycline to Treat Anaplasmosis in Fattening Lambs

“…Furthermore, previous investigations revealed differences in the pharmacokinetics of doxycycline between young calves and mature ruminants [ 28 ]. In a comparative study that was carried out on the pharmacokinetics of orally administered doxycycline in lambs and lactating ewes, it was observed that the values of clearance were significantly higher in adult sheep and that the plasma concentration was higher in lambs [ 29 ]. However, in calves, it was observed that after intravenous doxycycline administration.…”

Clearance of Mycoplasma ovipneumoniae in Captive Bighorn Sheep (Ovis canadensis) Following Extended Oral Doxycycline Treatment

“…Although doxycycline has broad spectrum activity, it is particularly beneficial in treating infections involving atypical bacteria and bacteria that lack a cell wall, such as Mycoplasma and Rickettsia species (Holmes and Charles 2009). Both oral and parenteral administration have been described in domestic sheep, goats, and cattle (Meijer et al 1993; Ole-Mapenay and Mitema 1997; Castro et al 2009; Castro Robles et al 2012; Mileva et al 2020). Tetracycline antibiotics have a wide tissue distribution, but doxycycline is more lipid soluble than other tetracyclines, providing greater tissue penetration and a longer half-life (Shaw and Rubin 1986).…”