The suburethral diverticulum
Keywords: vestibule, urethra, bovine, diverticulum, suburethral
The suburethral diverticulum can rarely become pathological enlarged, fluid filled and even cause stranguria. Its physiological importance is unknown. Its main importance to clinicians is the obstruction it can pose during catheterization of the urethra. It is present in domestic ruminants, pigs and camelids and should be born in mind when collecting urine in these animals. It is absent in horses.
The location of the diverticulum is shown here. A ghost image shows the position of a probe within the diverticulum, outlined in red. The urethra is shown as a green ghost image. Note the black wedge between the diverticulum and the caudal opening of the urethra. This shows that the urethra does not open directly into the vestibule but into the caudal part of the roof of the diverticulum.
Image size: 813 x 550 px
The length of the diverticulum in cattle is 1.5 to 2 cm long and 3 cm from its cranial-most extent to the where it enters the vestibule caudally. Its volume is approximately 4 ml. The image below is a caudal to cranial view of the diverticulum, seen from the vulva lips.
Image size: 3453 x 2016 px
There are several techniques that one can employ to avoid the potential frustration of passing a urinary catheter in cattle. One technique is shown below. A gloved finger is inserted into the diverticulum while a catheter (a very large probe in this case!) is inserted into the urethra. Urinary catheters usually enter the diverticulum by default. Therefore, an alternate method is to insert a rigid catheter into the diverticulum and to draw it caudally with the tip moving across the roof of the diverticulum, stretching it dorsally. Just before the tip of the catheter exits into the vestibule it is directed cranially, In that manner, it will usually enter the urethra.
Image size: 1292 X 1044 px
References:
Blazquez, N.B. et al 1987 Histology and histocehmistry of the bovine reproductive tract caudal to the cervix. Part 1. The vsetibule and associated glands B Vet J. 143, 328-337
