The aim of this study was to investigate the plasma concentrations of
folic acid,
vitamin B12 and
progesterone at different stages of the sexual cycle and pregnancy, during
induced abortion and in bitches with
pyometra. Bitches (n = 97) were assigned to groups as follows: a) oestrous cycle (n = 42) b) pregnancy (n = 25) c) induction of abortion (n = 10 and d)
pyometra (n = 20). Oestrous cycle stages were determined by vaginal inspection and cytology. Pregnancies were estimated by ultrasound (5.0 Mhz; linear transducer; Schimadzu) at days 15-25, 35-45 and 46-63 of pregnancy. Treatments for the induction of abortion were started between days 25 and 35 after mating (5 microg/kg
cabergoline daily,
Galastop; 5-10 microg/kg
Alfaprostol every other day, Gabbrostim). Diagnosis of
pyometra was confirmed by ultrasound and vaginoscopy.
Folic acid and
vitamin B12 concentrations did not differ among different stages of the oestrous cycle. The mean concentration of
folic acid during early pregnancy (days 15-25) exceeded levels of later stages (days 46-63): 9.4 +/- 3.7 microg/ml and 4.7 +/- 1.8 microg/ml, respectively (p < 0.01). A positive correlation between
folic acid and
vitamin B12 was determined in pregnant dogs ( r = 0.925; p < 0.02). Before the induction of abortion, the concentration of
folic acid was 9.6 +/- 5.2 microg/ml; during abortion it decreased to 5.0 +/- 3.2 microg/ml (p < 0.01). A significant correlation (r = 0.925; p < 0.02) between
progesterone and
folic acid was obtained in bitches with abortion. The mean concentration of
folic acid in bitches with
pyometra significantly differed from that of bitches at different stages of the oestrous cycle (p < 0.05). The mean concentration of
folic acid was significantly lower in metoestrous bitches when compared to bitches with
pyometra (p < 0.05). The decrease of serum concentrations of
folic acid during pregnancy and
induced abortion show that fetal growth and abortion caused higher consumption of
folic acid. Concerning bitches did not show any deficiency symptoms, which is why it can be concluded that this decrease is physiological.