Use of Endometrial Cytology and Bacteriology to Diagnose Endometritis in Infertile Bitches
Very few reports have been made about endometritis in the bitch. Today, transcervical catheterization by vaginal endoscopy allows us to evaluate the endometrium. Diagnosis criteria were determined according to previous studies on uterine cytology and bacteriology. The aim of our study was to test the efficiency of this technique to diagnose endometritis and furthermore, to evaluate its incidence within infertile bitches.
Material and Methods
Twenty-six bitches presented for infertility in Alfort Veterinary College were included. Classical infertility investigations were not indicative. A vaginal endoscopy was performed and presence of vaginitis and cervical discharge were evaluated. Then, a transcervical catheterization was performed using a human ureteral catheter (Ureteral CRU® ch.6 223602). Flushing of the uterine lumen was realized with sterile saline fluid (NaCl 0.9%, 2mL/10 kg instilled then reabsorbed) and collected samples were used for uterine cytology and aerobic bacteriology. If cytology pointed out an inflammatory state correlated to bacterial heavy growth, the bitch was considered to suffer from infectious endometritis. A cytologic inflammatory state of the uterus in the absence of bacterial growth was considered to be a non infectious endometritis.
Ten out of twenty-six bitches suffered from endometritis. Among them, seven suffered from infectious endometritis. Three bitches had a bacterial heavy growth without cytologic abnormalities and it was considered as a sign of contamination by the normal vaginal flora.
Infectious endometritis was diagnosed during dioestrus (6/7) and prooestrus (1/7). Non infectious endometritis was diagnosed in dioestrus (2/3) and anoestrus (1/3).
Four bitches for which endoscopy was performed in dioestrus encountered pyometra after flushing, two of which were not initially suffering from endometritis.
Five bitches suffering from endometritis were further bred after treatment combining antibiotics +/- aglepristone: they all went pregnant.
Endometritis seemed to have in most cases an infectious origin but these results may be underestimated, as some other pathogens (anaerobic bacteria, mycoplasmas, fungi), were not searched for. Dioestrus seems to be the best period for diagnosis. However, the endometrium impregnated with progesterone is more sensitive and despite all precautions, this could explain that we got induced pyometra after endoscopy. Early anoestrus may be a more adequate period as progesterone impregnation is over.
Impact of endometritis is underestimated and, in our opinion, should be investigated in each unexplained case of infertility in bitches. The technique used here seems reliable: all bitches treated were bred successfully whereas previous infertility treatments had not succeeded. Defining more accurate criteria will improve its efficiency.