Fertility in two cats with X-chromosome mosaicism and unilateral ovarian dysgenesis

Two pregnant cats showed unilateral ovarian dysgenesis at surgery. Cytogenetic examination revealed a 37,X/39,XXX karyotype in Cat 1, a 37,X/38,XX karyotype in Cat 2 and a marked difference in frequency of mosaicism between fibroblasts and lymphocytes in both cats. Histologically the ovarian morphology ranged from normal to complete dysgenesis in both cats. Three fetuses examined showed a normal feline karyotype.