Uterus unicornis and pregnancy in two feline littermates

Abstract

Case series summaryA queen, tom and four 1-year-old female offspring presented for routine neuter. Two of the littermates (cats 1 and 2) were diagnosed with a uterine abnormality during surgery. The left uterine horn of both cats appeared as a thin, solid, cord-like structure, whereas the right uterine horn of both cats appeared to have intermittent bulges consistent with pregnancy. The two other littermates, queen and tom were reproductively normal. The uteruses of the affected cats were nearly identical with a gross and histopathologic diagnosis of uterus unicornis with concurrent pregnancy. Ovaries were present, bilaterally. An oviduct was present only on the single normally developed and pregnant uterine horn in both cats. At a postoperative follow-up evaluation, abdominal ultrasound was performed on the two cats with uterine abnormalities. Cat 1 was ultrasonographically within normal limits. Cat 2 was diagnosed with ipsilateral renal agenesis on the same side as the absent uterine horn.Relevance and novel informationThe complexity of uterus unicornis and renal aplasia is demonstrated by this unique presentation of five related cats for ovariohysterectomy. This report raises questions regarding the genetic, environmental, hormonal or other underlying causes of this anatomic abnormality in cats that may spur additional research. This is the first publication describing uterus unicornis in gravid feline littermates, with one of the cats having ipsilateral renal agenesis. This is also the first publication to describe oviduct agenesis on the affected uterine horn in feline uterus unicornis.

Anti-Müllerian hormone as a diagnostic tool to identify queens with ovarian remnant syndrome

“… 28 A genetic influence seems possible because the occurrence has been described in littermates. 29 Uterus unicornus may occur with or without renal agenesis, but all of the reported animals had two ovaries, 30 and affected animals can become pregnant. 29 The left ovary of the cat in this study was without an ovarian bursa or an oviduct and had a subjectively longer, thinner and flatter appearance than normal ovaries.…”

“… 29 Uterus unicornus may occur with or without renal agenesis, but all of the reported animals had two ovaries, 30 and affected animals can become pregnant. 29 The left ovary of the cat in this study was without an ovarian bursa or an oviduct and had a subjectively longer, thinner and flatter appearance than normal ovaries. Furthermore, the ovary seemed to be in a more cranial position and was more strongly attached to the dorsal peritoneum than the ovaries of a normal developed genital tract.…”

Genital abnormalities associated to lack of uterine adenogenesis or endometrial gland dysgenesis of female dromedary camels (<i>Camelus dromedarius</i>)

“…The endometrial gland anomalies would be causing the impediment of gestation by alteration of uterine receptivity, blastocyst/ conceptus survival and implantation, and stromal cell decidualization (Filant and Spencer, 2014;Gray et al, 2001b). The uterine aplasia in some mammal species as cat (Brookshire et al, 2017), cow (Moriyama et al, 2008), and mare (Gallacher and Gilbert, 2018) does not prevent pregnancy. In camelids, missing left uterine horn could lead to infertility as long as nearly all pregnancies occur in the left side (Ali et al, 2015;Gherissi et al, 2017;Tibary and Anouassi, 1997).…”

Disorders of sexual development in the cat: Current state of knowledge and diagnostic approach

“…The affected portion of the uterus is missing but the mesometrium remains. The missing portion is often one uterine horn (Figure 3), 10,21,[24][25][26] but there are reports of failure of the cervix and cranial vagina to form. 21,27,28 Any remaining uterus craniad to the missing portion will be dilated and filled with fluid or inspissated contents.…”

“…One site of placentation is prominent (P). Reproduced, with permission, from Brookshire et al (2017) 10…”