Congenital abnormality of the vagina complicated by hemato-pyocolpos in a 1-year bitch

Abstract

Clinical case. A 1-year-old female Labrador Retriever was referred with a few days history of hematic-like vulvar discharge, an occasional episode of vomiting, overall good appetite, but slight general dullness. Physical examination did not reveal any anomaly other than the vulvar discharge. A vaginal swab was performed for microbiological evaluation. Vaginal inspection and palpation did not reveal any remarkable finding. Transabdominal ultrasound showed echogenic fluid accumulation in the vagina suggesting hemato-pyocolpos. Vaginal smear revealed a late proestrous/early estrous phase with a high number of RBC and superficial epithelial cells. Hematology and biochemistry profiles were within the normal range. An exploratory laparotomy was performed: a well-delimited ectasic vagina was identified. Adhesions on the bladder and on the ureters were present. A free-hand fine-needle aspiration of the lesion was performed with a 21G needle to collect 5 mL of fluid for microbiological evaluation. Ovariohysterectomy (OVH) and partial vaginectomy and vaginoplasty were performed to spay the bitch and to remove the ectasic vagina. Postoperative recovery was uneventful and the dog was discharged with a prescription of cephalexin (30 mg/kg BID), tranexamic acid (15 mg/kg SID) and the elizabethan collar. The microbiological examination revealed a severe presence (>103 CFU) of Pasteurella multocida both in pre-surgical vaginal swabs and in the fluid collected intraoperatively. Upon antibiotic sensitivity test, marbofloxacin (2 mg/kg SID for 6 days) was administered. Vaginal discharge disappeared few days after the surgery. Ten days later, wound healing was satisfactory and 1 month after surgery cranial vaginal swab was sterile. The genital tract was evaluated grossly and histologically. The vaginal ectasia was characterized by an irregular muscular wall mixed with edematous connective tissue. The mucosal epithelium was multifocally ulcerated, characterized by vascular damage (thrombi) and an active chronic purulent inflammation. Discussion. Clinical, morphological and histological findings were consistent with a congenital abnormality of the muscular layer of the vagina complicated by hemato-pyocolpos. During organogenesis both the paramesonephric ducts and the urogenital sinus fuse and participate in the formation of the vagina with the mucosal epithelium deriving from the utero-vaginal tract, and the muscular layers from the mesenchymal sheath (1). Congenital defects, as septa, strictures, segmental aplasia, presence of the hymen, are linked to disorders occurring in this process (2). In human medicine these congenital disorders complicated by hydro/hemato/pyocolpos have been described in newborn babies or during puberty (3,4,5). In the bitch pyocolpos caused by the presence of segmental aplasia or imperforate hymen have been reported (6,7). In the present case the only finding was the disorganization of the vaginal tunica muscolaris that may have been locus minoris resistentiae in the vaginal wall. The organ was dilated and atonic due to the gradual collection of physiological fluids complicated by an overgrowth of genital bacteria. A delayed diagnosis of pyocolpos may result in uterine disorders, pelvic infection and adhesions. Surgery is the gold standard treatment; OVH and vaginoplasty should be performed before further complications arise. This congenital disorder have to be taken into account as differential diagnosis of hemato-pyocolpos with vaginal discharge in young bitches. References. 1) Schatten and Costantinescu. Comparative Reproductive Biology, 2007, Blackwell Publishing. 2) Johnston et al. Canine and Feline Theriogenology, 2001, WB Saunders, Philadelphia. 3) Brevetti et al. J Pediatr Surg, 1997;32:110-1. 4) Tran et al. Am J Dis Child, 2007;141:632-4. 5) Tseng et al. J Chin Med Assoc, 2008;71:325-8. 6) Wadsworth et al. Lab Anim, 1978;12:165-6. 7) Marinho et al. J Morphol Sci, 2013;30:206-8