Effects of Leuprolide Acetate on Selected Blood and Fecal Sex Hormones in Hispaniolan Amazon Parrots (Amazona ventralis)

The luteinizing hormone–releasing hormone agonist leuprolide acetate is used commonly to manage reproductive problems in pet birds. To determine the effect of leuprolide acetate on plasma and fecal hormone levels in a psittacine species, a single 800 µg/kg dose of the 30-day depot form of leuprolide acetate was administered IM in 11 healthy, nonbreeding adult Hispaniolan Amazon parrots (Amazona ventralis), and plasma and fecal hormone levels were measured before and after leuprolide administration. At pooled baseline to 21 days postleuprolide acetate administration, sample collection day was significantly associated with plasma 17β-estradiol and androstenedione levels and fecal 17β-estradiol levels (evaluated in females only). Both plasma androstenedione and plasma 17β-estradiol levels decreased significantly from baseline to a nadir at 7 days postleuprolide acetate administration but did not differ significantly 14 days later from that nadir or from pooled baseline samples, suggesting that the effect of leuprolide on hormone levels remained about 2 weeks. Fecal 17β-estradiol levels increased significantly from the nadir at 7 days postleuprolide to 21 days postleuprolide administration, with trends of the level at 21 days postleuprolide being higher than the pooled baseline level and of decreasing levels from pooled baseline to 7 days postleuprolide administration. Plasma luteinizing hormone and fecal testosterone levels did not change significantly from baseline levels after leuprolide administration over the 2-day period. No significant correlations were found between plasma hormone and fecal hormone levels. These results suggest that measurement of plasma androstenedione, plasma 17β-estradiol, and fecal 17β-estradiol levels might be useful in assessing the effects of 30-day depot leuprolide acetate in Hispaniolan Amazon parrots.