Depression of ovarian function and plasma progesterone and estradiol-17 beta in female goats chronically infected with Trypanosoma congolense.

Adult normocyclic female goats experimentally infected with Trypanosoma congolense developed irregular and shorter estrous cycles before complete cessation at the fourth cycle post-infection. This was followed within a month by a decline in the mean plasma progesterone and estradiol-17 beta levels. The peak luteal progesterone as well as pre-ovulatory estradiol-17 beta level declined progressively from the second to the fourth cycle post-infection. The ovaries became atretic with reduced numbers of primordial and primary follicles. The larger follicles became atretic at the tertiary stage with subsequent lack of corpora lutea formation. The rapidity of ovarian dysfunction appeared to be related to the degree of susceptibility of the individual infected goats.