Page 240 - Clinical Manual of Small Animal Endosurgery

228 Clinical Manual of Small Animal Endosurgery

Fig. 7.21 Injecting bulking agent for USMI via a 23 gauge needle in the
proximal urethral mucosa.

bronchoalveolar lavage is often suitable. If tubing is not used the needle
tends to slip to the side of the telescope making the needle tip difficult
to manipulate and visualise. The tubing keeps the needle central above
the endoscope and prevents it moving from side to side.
A small flexible connector is attached to the Luer hub of the needle
at one end and the syringe holding the bulking agent at the other. The
needle tip is advanced into view and the bevel is turned towards the
lumen of the urethra. The tip of the needle is advanced into the submu-
cosa (Fig. 7.21) and approximately 1 ml of bulking agent is injected
submucosally at three equidistant points around the urethral circumfer-
ence, keeping the needle in situ for 30 s or so after each injection to
reduce back flow occurring at removal. It is preferable to have an assist-
ant make the injection since the endoscopist may find it difficult to
maintain the tip of the needle in the correct place throughout the proce-
dure. The mucosa will be seen to swell up and partially occlude the lumen
after each injection (Fig. 7.22). Dedicated endoscopic equipment is avail-
able for this procedure. Although this makes manipulation of the needle
more precise for the endoscopist, the diameter of the sheath restricts its
application to bitches of approximately 15 kg and larger.

Transcervical catheterisation for artificial insemination
Cervical catheterisation requires considerable practice. The procedure is
usually carried out in a conscious bitch and without the benefits of saline
infusion to expand the vagina (Lhermette and Sobel, 2008). During
oestrus the cervical os is dilated, thus facilitating the procedure. However,
sedation may be required in some bitches.
The cystoscope is passed into the vestibule and then through the
vaginal os to the cranial end of the vagina. In giant breeds a 4 mm,