Peripheral plasma progesterone concentration and haematological indices during normal pregnancy of chinchillas (Chinchilla laniger, M.).

Peripheral plasma progesterone concentration and some haematological indices in pregnant chinchillas were studied. As pregnancy advanced progesterone concentration showed a marked change from high values in early pregnancy (days 9-29), to undetectable values by days 40-60, and from high values in the latter states of pregnancy (days 70-80), to very low values during the 30 days before parturition. Haematocrit value and mean erythrocyte volume change inversely to progesterone concentration fluctuations. White blood cell parameters increased during the first half of pregnancy, then decreased to the lowest level before parturition.