Exotic small mammal elective surgery (Proceedings)
Rabbits should be spayed anytime after 5 months of age. When very young, the uterine horns and ovaries are very tiny making identification challenging. However, in older mature and perhaps overweight rabbits, the mesometrium is extremely fatty and friable. OVH is indicated in all female rabbits to prevent pregnancy, control territorial aggression, prevent uterine neoplasia (80% incidence), or other uterine disorders such as pyometra. Unique anatomy for the rabbit is their bicornuate cervix, long convoluted and fragile fallopian tube, and a flaccid vaginal body that will fill with urine during micturition, and a very large amount of fat is common in the region of the broad ligament and suspensory ligament (making it difficult to ID the ovarian and uterine vessels)
Surgical TechniqueA 2-3cm midline incision is made approx. half way between the umbilicus and the pubic symphysis. The linea is identified and grasped and greatly elevated with thumb forceps as a stab incision is made into the abdomen. Great care is taken when entering the abdomen as the very large and very thin walled cecum and urinary bladder often lay directly against the ventral abdominal wall. The GI tract should be minimally handled to minimize the likelihood of post op adhesions. A spay hook is not necessary as the uterus is easily visible and can be gently lifted through the incision using fingers or forceps. The uterus is followed to the oviduct and infindibulum. These may be embedded in fat and gentle digital manipulation and traction will allow for identification of the ovary and its vasculature. .The ovarian vessels are double ligated using PDS or Monocryl suture. The procedure is repeated for the opposite ovary. The uterus and its vessels are identified. The vessels are double ligated separate from the uterine body. The uterus can then be ligated cranial or caudal to the cervices. Closure of the abdomen with a 4-0 or 3-0 monofilament absorbable suture is routine. Simple continuous or interrupted in the linea followed by simple continuous pattern in SQ/intradermal.
Rabbits should be castrated to control urine marking behaviors, prevent reproduction, control and minimize territorial aggression, and avoid chance of testicular tumors.
Both prescrotal and scrotal techniques have been described. The scrotal technique is very similar to the cat. Complication of scrotal edema and hematoma is reported. An incision is made in the scrotum in a non-vascular region being careful to not incise the vaginal tunic. A hemostat is used to help separate/free the testicle from the scrotum and the testicle with gentle pressure is manipulated out of the incision. The caudal ligament of the testicle is torn from its scrotal attachment, completely freeing the testicle and spermatic cord. The spermatic cord is clamped distal to the testicle and close to the inguinal ring. The spermatic cord is double ligated using 4-0 absorbable suture and then resected. The scrotal skin is apposed using tissue glue. The procedure is repeated for the opposite testicle. For the prescrotal technique a 1.5cm incision is made on the midline just cranial to the scrotum similar to a akin incision for a canine castration. One of the testicles is manipulated toward the incision by applying gently digital pressure on the scrotum. It the testicle is withdrawn into the abdomen, gentle pressure is applied to the abdomen to return testicles to their normal position. The fat is dissected away with hemostats to expose and isolate the vaginal tunic. The vaginal tunic is lifted up and the caudal ligament of the testicle is carefully torn from its scrotal attachment, freeing the testicle and spermatic cord. The spermatic cord is clamped distal to the testicle and close to the inguinal ring. The spermatic cord is double ligated using 4-0 absorbable suture and then resected. The procedure is repeated for the opposite testicle. The subQ tissue is closed with a simple continuous pattern followed by a continuous intradermal skin closure.