If the urethral orifice is not visualized, reinsert the insertion guide into the speculum before advancing the speculum into the vagina. Note the edge of the speculum is sharp. This is what the view looks like through the scope. The arrow points to the urethral orifice. The other two lines in the vaginal mucosa are folds in the tissue.
Some bitches have a prominant mound of raised tissue around the urethral orifice.
Gently probe the urethral orifice with the urinary catheter to confirm that it is the urethral orifice and not a fold of tissue. This is a Foley catheter being placed throughthe otoscope. Magnification makes it easier to see the urethral orifice. You can use a stainless steel catheter as a stylet for a Foley catheter. The steel catheter is fitted into the eye of the Foley and the two are passed together into the bladder.