Cloacopexy is indicated for treatment of chronic cloacal prolapse. Several procedures have been recommended for the treatment
of chronic cloacal prolapse. Because the exact cause of the problem has not been determined, recurrence is observed with all
techniques. Even if permanent adhesions are created, the sphincter is typically stretched out and atonic. The cloaca itself
often stretches (megacloaca) and the redundant tissue prolapses out the vent which has the appearance of a recurrence.
I use a combination of three procedures to reduce the prolapse, maintain its position, and reduce the size of the vent opening.
Make a ventral midline incision in the abdomen. Extend the incision parasternal on both sides. Remove fat from the ventral
surface of the cloaca that might inhibit the formation of strong adhesions. Insert an appropriate structure into the cloaca
to define its limits. The circumcostal cloacopexy uses the last rib to which the cloaca is sutured to maintain reduction.
In birds with cloacal prolapse, there is generally not too much tension when this is done. As an alternative, the organ can
be sutured to the caudal border of the sternum. Preplace 2 sutures around the rib at the angle on each side or through the
cartilaginous border of the sternum and full thickness through the cloaca. This will anchor the organ in a reduced position;
however, the suture will eventually stretch, break, or cut through resulting in failure. To prevent recurrence, permanent
adhesions must be created. Close the ventral midline incorporating the cloaca creating a cloacopexy. Scarify, incise, or resect
the ventral cloaca to create a raw surface. Pass the suture through one side of the body wall incision, full thickness through
the cloaca, and through the other side of the body wall. This encourages the cloaca to heal within the body wall forming permanent
adhesions between these structures. Ventplasty is indicated in birds with chronic cloacal prolapse where the vent sphincter
has become atonic. This may be the result of chronic straining or a primary neuropathy. The sphincter is incompetent and is
no longer able to prevent the cloacal tissues from prolapsing. Ventplasty (analogous to canthoplasty of the eyelids) is used
to decrease the size of the vent opening.
Incise the skin over the vent sphincter at the lateral commissures exposing the underlying muscle. Place fine monofilament
absorbable suture transversely in the mucosa from cranial to caudal. Next, the vent sphincter muscle is apposed with a synthetic
absorbable in a mattress pattern between the cranial and caudal aspects of the sphincter. Finally, the skin edges are apposed
cranial to caudal using a synthetic absorbable material. Remove enough tissue from each side so that only 1 or 2 cotton tipped
applicators can be passed through the vent. Postoperatively, the patient is monitored to assure that it can still void urine,
urates, and fecal material. Some birds will develop stricture a few weeks after this procedure. Under general anesthesia,
stretch the sphincter with a cotton tipped applicator in a circular motion. In birds that have had strictures, I have only
had to do this procedure once.
In most adult birds, the right reproductive tract is virtually nonexistent. The arterial supply is through the ovario-oviductal
branch of the left cranial renal artery with venous drainage through 2 ovarian veins into the caudal vena cava. These vessels
and many nerves enter through a broad based ovarian hilus on the dorsal aspect of the coelom. The magnum is the longest and
most coiled portion of the oviduct and has numerous tubular glands which are responsible for the white of the egg. The isthmus
is a narrowing in the oviduct with less prominent folds and a transparent junction with the magnum. The shell membranes are
produced in this section. The uterus (shell gland) has no distinct separation from the oviduct and it is in this location
that the shell is applied. The vagina is attached to the cloaca and is in an S configuration. It is very thick and muscular
but has no glands. The oviduct and uterus are suspended from the dorsal coelom by a double layer of peritoneum which forms
the dorsal and ventral ligaments. These ligaments contain smooth muscle which is responsible for transporting the egg along
the pathway. The ventral ligament comes together caudally as a thick muscular band which attaches to the caudal uterus and
vagina. The oviduct is supplied by three major blood vessels: the cranial oviductal artery is a branch of the left renal artery,
the middle ovarian artery is a branch of the ischiatic artery, and the caudal ovarian artery is a branch of the pudendal artery.