PATHOLOGICAL-CHANGES RELATED TO SUBCUTANEOUS IMPLANTATION OF CHLORMADINONE ACETATE FOR PREVENTING ESTRUS IN BITCHES

Pathologic changes related to chlormadinone acetate (CAP) implantation were examined using 14 bitches given doses 2.5 to 25 mg/kg for 2 year s. Absence of corpus luteum in bitches given 5 mg/kg or more supported long-term preventive effect of CAP on estrus. The uteri were dose-dep endently enlarged and mucometra was occasionally found. Endometrial ep ithelium hyperplasia was observed but less in smaller doses. Changes i n the mammary gland were only growth and lactation at normal degrees. No remarkable changes were observed in ACTH and LH cells in the pituit ary gland. Low, stable levels of CAP maintained in plasma by subcutane ous implantation seemed to be the main reason for absence or slight CA P-related pathologic changeS.