Pharmacological and pharmacokinetic differences between donkeys and horses

Pharmacokinetic Evaluations of Sulpiride After Intravenous, Intramuscular, and Oral Single-Dose Administration in Jennies (Equus asinus)

“…The IM F% was 73.5%; this is not in line with some previous data in horses where bioequivalence between IV and IM administrations was reported [12]. This fit with the well-documented PK differences between donkeys and horses [22]. The donkey therefore should not be regarded as a small odd-looking horse but should be recognized and treated as a species in its own right.…”

Plasma pharmacokinetics, faecal excretion and efficacy of pyrantel pamoate paste and granule formulations following per os administration in donkeys naturally infected with intestinal strongylidae

“…Because of the lack of drugs approved for use in donkeys, anthelmintics licensed for use in horses or ruminants are used at the same dosages for treatment of parasitic infections in donkeys. It has been reported that donkeys have a greater capacity to metabolize certain drugs, compared with the capacity for horses; thus, higher dosages or shorter intervals could be required to maintain effective drug concentrations in donkeys (Welfare et al, 1996;Matthews et al, 1997;Coakley et al, 1999;Peck et al, 2002;Lizarraga et al, 2004;Grosenbaugh et al, 2011). Hence, in the present study, the pharmacokinetic disposition, faecal excretion and anthelmintic efficacy of two different formulations (paste and granule) of PYR pamoate are reported in donkeys naturally infected with intestinal strongylidae after oral administration.…”

Subspecies Studies: Pharmacokinetics and Pharmacodynamics of a Single Intravenous Dose of Xylazine in Adult Mules and Adult Haflinger Horses

“…Significant differences in the pharmacokinetics (PK) and pharmacodynamics (PD) of several intravenously administered drugs have been reported from comparison studies between horses, donkeys, and mules [4][5][6][7][8][9][10][11]. Investigations of anesthetic drug combinations in donkeys and mules [5,6,10,11] have demonstrated the necessity to find adequate anesthetic regimens for each of this species.…”