Table 1 The effect of letrozole administration (72 µg/kg, PO) on concentration (means ± SD) and changes of testosterone, estradiol, and estradiol: testosterone ratio in serum and semen samples studied before (day 0), during (day 14 and 28), and after (day 42) treatment of adult mixed breed dogs

Testosterone (ng/ml)

Serum

11.61 ± 18.53^a

44.55 ± 18.90^b

40.95 ± 19.48^b

61.80 ± 2.12^b

432.30

Seminal Plasma

0.14 ± 0.15^a

5.89 ± 8.91^ab

13.95 ± 11.02^b

26.30 ± 11.42^bc

18685.71

Prostatic fluid

0.12 ± 0.09^a

6.62 ± 12.26^ab

14.44 ± 16.18^ab

18.33 ± 13.80^b

15175.00

Estradiol (pg/ml)

Serum

116.39 ± 46.71

352.63 ± 279.14

396.76 ± 302.04

385.40 ± 424.83

231.13

Seminal Plasma

75.09 ± 32.89^a

111.70 ± 11.56^b

106.27 ± 11.50^ab

104.96 ± 24.54^ab

39.78

Prostatic fluid

90.49 ± 28.78

110.23 ± 20.27

117.17 ± 14.27

94.59 ± 33.24

4.53

Estradiol: Testosterone Ratios

Serum

0.11 ± 0.12^a

0.01 ± 0.01^b

0.01 ± 0.01^b

0.006 ± 0.006^b

-94.55

Seminal Plasma

0.82 ± 0.62^a

0.11 ± 0.10^b

0.05 ± 0.08^b

0.005 ± 0.003^b

-99.39

Prostatic fluid

1.15 ± 0.81^a

0.17 ± 0.13^b

0.07 ± 0.09^b

0.01 ± 0.02^b

-99.13