Therapy and evaluation of early embryonic loss in a subfertile bitch

A five year old intact female Cardigan Corgi was presented with a history of infertility and pregnancy loss. Interestrus interval reported was consistent (every 6 - 7 months), except for the last interval, which was reduced to 4½ months. Bitch was inseminated 5 times in 2 years. Surgical insemination using frozen semen was successful, and 2 puppies were whelped. Since then, bitch was inseminated with fresh or cooled semen 4 times (1 vaginal, 1 surgical, and 2 transcervical). It was suspected that pregnancy was either not established or lost in midpregnancy. Last insemination was performed 2 months before presentation. Local veterinarian diagnosed pregnancy via a relaxin assay and abdominal ultrasonography. Due to history of infertility, another abdominal ultrasonography was performed the following week, and early embryonic death was noted. On presentation, bitch appeared healthy and bright with normal physical parameters, and there was no vulvar discharge. Complete blood count and chemistry were within normal limits. Vaginal cytology had scant cellularity; noncornified parabasal cells, scant red blood cells, with few neutrophils and bacteria noted. Serum progesterone concentrations were 1.1 ng/ml. Brucella canis serology was negative. Vaginal samples were submitted for Mycoplasma and aerobic cultures. Scant growth was noted on Mycoplasma culture. Ultrasonographic evaluation revealed the presence of 8 mm echogenic fluid in right uterine horn and 2 mm fluid in left uterine horn. Both uterine horns contained thickened foci with a hypoechoic central region and hyperechoic luminal margins, consistent with necrotic placental zones. Uterus had multifocal cystic endometrial hyperplasia with several 4 mm cysts. Ovaries were normal and had luteal tissue. Renal cortical calcifications with normal abdominal content were noted. As bitch appeared clinically and systemically stable, 3 weeks of oral enrofloxacin (12 mg/kg) and Clavamox ® (14 mg/kg) were prescribed for possible risk of fulminant pyometra. Two weeks of topical vaginal Misoprostol, 1 µg daily, was prescribed for cervical dilation. Future mibolerone administration was discussed to prolong anestrus, but was declined. Electro-acupuncture was performed several times and bitch was given an oral "lotus formula". One month later, ultrasonographic examination revealed an involuted uterus with no free fluid present and 2 small cysts. Two months later, no free fluid or cysts were present. Bitch will be bred at next estrus to a proven male, with results pending.

Keywords: Canine, infertility, cystic endometrial hyperplasia, early embryonic death

This manuscript was originally published in the journal Clinical Theriogenology Vol 12(3) Sept 2020.  Clinical Theriogenology is the official journal of the Society for Theriogenology (SFT) and the American College of Theriogenologists (ACT).  This content has been reproduced on the IVIS website with the explicit permission of the SFT/ACT.