Kalthum W, Waterman A E
Department of Veterinary Surgery, University of Bristol, Langford.
Br Vet J. 1990 May-Jun;146(3):243-8. doi: 10.1016/s0007-1935(11)80009-6.
The urinary excretion of pethidine and its major metabolite, norpethidine, was investigated in four male dogs given pethidine as a postoperative analgesic. The urinary excretion of pethidine in the first 4 h after drug administration was low at 1.9% of the administered dose. The percentage of the drug excreted as norpethidine was also low at 3.7% but there was a great deal of individual variation. Urinary excretion, therefore, appears to be a minor route in the clearance of pethidine in the dog.