Effect of cyclophosphamide on erythrocyte and plasma acetycholinesterase activity in sheep.

Twenty-seven 4to 6-month-old crossbred ewe and ram lambs were assigned at random within sex to dosages of 10, 20 or 30 mg of cyclophosphamide (CPA), a chemical defleecing agent, per kilogram of body weight. Erythrocyte and plasma acetylcholinesterase (ACHE) activities were measured in jugular blood before CPA treatment and 1, 5, 9, 13, 17, 2 i and 26 days thereafter. As in man, both plasma and erythrocyte AChE activities were depressed following CPA treatment, reaching their lowest levels on days 9 and 1, respectively. No physical signs of depressed AChE activity were observed in any of the sheep. The depression of neither the plasma or the erythrocyte enzyme can be used presumptively to identify sheep that have been treated with CPA before that fact is evident from the woold itself. (