Medroxyprogesterone acetate as an aid to birth control programme in stray dogs

Abstract

The utility of Medroxyprogesterone acetate as an aid in the birth control programme of stray dogs was studied. Eighteen early proestrus bitches were randomly allotted to three equal groups (Group A Group B and Group C). Group A animals were administered with a single subcutaneous injection of 50 mg medroxyprogesterone acetate. Group B animals were administered medroxyprogesterone acetate orally at the rate of 10 mg per day for four days followed by 5 mg per day for another 12 days starting from the end of anoestrus. Six bitches of Group C acted as control animals. All animals in Group A and Group B responded to the treatment though one animal in Group A had returned to cycle in about 50 days. Reproductive cycle was controlled in all six animals of group A at a mean of 3.17 days and a mean of of 2.67 days in group B. Group A animals had a mean duration of control of 83.3 days while in group B it was 90 days. Vulval edema, vulval discharge, tail deviation reflex and interest in male decreased following treatment in Groups A and B while it seemed to be not changed or high in Group C animals. Detailed vaginal cytology was studied using Wright- Giemsa's stain. Cellular changes was characterized by a change from predominance of parabasal cells following treatment in Groups A and B while changes characteristic of oestrus cycle occurred in the control animals. There was significant difference in the mean percentage of parabasal cells between Groups A and B after treatment and during different stages of the oestrus cycle of the Group A up to end of dioestrus. Serum progesterone was estimated in all animals at fortnightly intervals. Animals in group A, B and C showed mean serum progesterone concentrations of 0.53 ng/ml, 0.57 ng/ml and 0.45 ng/ml during the beginning of proestrus. The mean progesterone in serum following treatment elevated in Group A to 27.83 ng/ml, while it maintained a low level of 0.55 ng/ml in group B and had a value of 4.43 ng/ml in group C which indicated oestrus phase. The progesterone level reached maximum concentration of 31.17 ng/ml on day 42 in group A and 49.00 ng/ml during dioestrus in group C. The values remained low in group B. Towards the end of experiment all animals had basal concentration of progesterone. It is concluded that reproductive control can be achieved effectively in bitches treated with medroxyprogesterone acetate by both oral and parenteral routes. Oral administration demand less technicalities and hence is more suitable for use in the field.