Uterine two-dimensional and Doppler ultrasonographic evaluation of feline pyometra.

The aim of this study was to compare uterine two-dimensional and Doppler ultrasonographic parameters in queens suffering from pyometra from those in early pregnancy. Secondly, the effect of the presence of clinical signs of systemic illness on these parameters was also described. Fourteen post-oestrous queens, with uterine luminal content in the absence of embryos were included. According to their outcome (pyometra surgery or parturition), the queens were retrospectively assigned to one of the following groups: Pyometra (PYO; n = 7) or pregnant (PRG; n = 7). In all the queens, two-dimensional and Doppler ultrasound examinations of the uterus were performed. The presence or absence of clinical signs of systemic illness was recorded. The widest cross-sectional diameter (UD), uterine wall thickness (WT), uterine lumen contents (LC) and uterine artery resistance index (RI) were measured. Uterine horn diameter was higher in PYO group than in PRG group (p < 0.05), while WT (p > 0.1) and LC (p = 0.09) did not differ between groups. Values of RI for PYO and PRG groups were 0.61 ± 0.03 vs 0.53 ± 0.09 (p < 0.05), respectively. PYO cats suffering from clinical signs of systemic illness showed larger UD than those without signs (p < 0.01). It is concluded that two-dimensional and Doppler ultrasound might be useful to distinguish queens suffering from pyometra from those in early pregnancy. Secondly, the clinical signs of systemic illness were associated with a larger UD.

Development and proliferation of feline endometrial glands from fetal life to ovarian cyclicity.

In this study it was determined the progression of uterine gland development from late gestation to puberty in domestic felids. Cell proliferation patterns for luminal (LE), glandular epithelium (GE) as well as stroma (S) were also described. Twenty-four uteri from female kittens: 45 and 65 days of gestation and 1 to 5, 8, 12, 16, 20 and 24 weeks postnatally were obtained. Uterine cross-sections were submitted for routine histological and immunohistochemical quantification of proliferating cell nuclear antigen (PCNA) techniques. Although prenatal uteri presented no indication of adenogenesis, 1 week old uteri revealed an incipient budding of the LE. During the second week budding increased and a mild degree of tubulogenesis of the GE into the stroma was detected. From the third to fifth weeks coiling, branching and cross-sections of glands appeared. These latter findings were more evident in week 8 when GE began to penetrate through much of the S to week 24. PCNA immunostaining revealed that DNA synthesis decreased throughout the study in the 3 cell compartments; (P < 0.01). Luminal proliferation began prenatally, it maintained up to postnatal week 8 to markedly decrease to puberty (P < 0.01). From postnatal week 3 up to week 8, GE mitotic activity was elevated becoming low thereafter (P < 0.01). Stroma actively proliferated prenatally (P < 0.01), diminishing up to week 8 (P < 0.01) and again during the last weeks (P < 0.01) of the study. It was concluded that, in domestic felids, proliferation of LE begins prenatally, histological uterine adenogenesis commenced during the first postnatal week and both events concluded by postnatal weeks 5-8.

Disrupting effect of androgens in postnatal female domestic cats.

To test the hypothesis that in domestic cats, postnatal androgens induce sterility, the aims of this study were to describe the reproductive effects and the clinical safety of a postnatal administration of a long term release androgen in this species. Thirteen newborn littermate female kittens were randomly assigned to one of the following treatment groups within the first 24h of birth: testosterone enanthate 12.5mg sc (TE; n=8) or Placebo (PL; n=5). The animals were subsequently assessed for fecal sexual hormones until puberty was attained and subsequently when matings occurred. After 21 days, ovulation and gestation were diagnosed. All queens were subsequently ovario-hysterectomized. Fecal testosterone concentrations differed between the treatment groups throughout the study period (P<0.05) being greater during the first 2 postnatal weeks in those of the TE group (P<0.01). Fecal estradiol was not affected by treatment (P>0.1). While all the females were receptive during the pubertal estrus (P>0.1), two TE (2/8) compared with all (5/5) females of the PL group had ovulations (P<0.05). Only one (1/2) compared with three (3/5) of the queens of the TE and PL groups, respectively became pregnant. All kittens of the TE group had transient clitoral enlargement. Anovulatory TE-treated cats had no corpus luteum, and a significant diminution of the endometrial glands as well as of the height of the uterine epithelium. It is concluded that, in domestic cats, a single postnatal supra-physiological dose of testosterone caused a large proportion of queens to be anovulatory and there were also histological endometrial abnormalities that also occurred with this treatment that were accompanied by mild and transient side effects.

Postnatal exposure to a progestin does not prevent uterine adenogenesis in domestic dogs.

To assess the effects of a single supraphysiological postnatal administration of a progestogen on uterine glands in dogs, 10 females were randomly assigned to a medroxyprogesterone acetate 35 mg (MPA; n = 6) or placebo (n = 4) group within the first 24 h of birth. The safety of the treatment was also evaluated. A transient mild clitoris enlargement appeared in MPA-treated females. Microscopic postpubertal uterine assessment revealed the presence of uterine glands in all cases without significant differences in the area occupied by the glands per µm(2) of endometrium nor in the height of the uterine epithelium.