NAVC Conference 2008 ______

SURGICAL TECHNIQUES FOR SPAYING x Do NOT use spay hooks of any kind RABBITS AND RATS x Avoid manipulation of GI tract at all costs. x Follow uterine horn cranially to Joerg Mayer, Dr.med.vet., MSc x Ovary is extremely small in relation to uterine horn, School of Veterinary Medicine and yellow Tufts University, North Grafton, MA o Left ovary is close to kidney x Identify ovarian artery and ligate immediately RABBITS o Hemoclips will speed procedure up Indications x Bluntly dissect along uterine horn x Intact females have a high rate of uterine o Radiocauthery can be used on smaller uterine adenocarcinoma , as high as 80% by age 3 years vessels and older x Repeat procedure on other side o Very high incidence of systemic metastasis x In young animals transection of uterine horn can be (mainly lung and liver) made cranial to x Intact females are impossible to keep together due o Will leave cervix behind and may provide an to constant fighting additional barrier against bacterial contamination x High reproductive rate from o Females can conceive within 24 hours post x In older animals remove cervices completely partum x Transection is performed in vagina (ovario-vagino- ) Anatomy o Reduces the chance of a subclinical uterine x The vaginal body is very long and more flaccid than cancer in remnant tissue in other species. x Close incision in a three-layer fashion x The vagina fills with urine during micturition. o Use an intradermal suture pattern x Two cervices (bicornute cervix or cervix duplex) are present as normal anatomy. Follow-up x The ovarian vessels are very well developed. x Make sure animal is eating, urinating and defecating x The bladder receives a branch from the uterine artery. Possible Complications x The and the uterine blood vessels are x Intestinal adhesions often encased in large amounts of fat, especially in o Fibrin clots older females. x Ligation of a ureter x The large intestine, especially the cecum, is in close x Leakage of urine from vaginal stump proximity to the surgery site. o If cervix is completely removed x Uterine cancer in the residual tissue Preparation o If cervices are not removed x All forms of stress should be avoided prior to surgery RATS o House rabbit in a quiet ward Indications o Avoid barking x Intact females have a high incidence of mammary o Try not to house a directly next to a rabbit cancer (adenoma/adenocarcinoma) o Avoid olfactory or direct visual contact between o As high as 66% by about 2 years of age (21 the rabbit patient and prey species months) x In older intact rabbits, do perform radiographs o Spayed rats have a significantly lower rate of and/or an ultrasound exam prior to surgery to check mammary cancer. for subclinical uterine neoplasia or metastasis. o If mammary cancer develops it usually has a low x Ideally a CBC and a chemistry panel should be run incidence of systemic metastasis (eg, lung and prior to anesthesia. liver) x Ensure that the doe is optimally hydrated: x High reproductive rate o Maintenance fluids are approximately 120 o Note: Intact female hamsters normally have a mL/kg/day vaginal discharge ƒ Often mistaken for Procedure Anatomy x Generally very similar to a spay. Approach by x The are located caudal to the kidneys in a ventral midline incision large fat pad x Make a 1- to 2-inch incision between umbilicus and x The uterine horn wraps around the ovary pubis x The ovarian vessels are not well developed o Make incision closer to umbilicus as ovarian x The ovarian ligament is very long and the ovary is ligaments are not ‘stretchable’ easily exteriorized x Cervices will be visible immediately in the incision 1854 Exotics – Small Mammals ______

Preparations o Less invasive x Evaluate patient thoroughly for subclinical forms of o Less painful respiratory disease or heart disease in older animals o Smaller incision (over 2 years old) o Less likely to see postsurgical incision x Ideally a minimal screen (hematocrit, total solids, complications due to self-mutilation or blood glucose and blood urea nitrogen) should be contamination with soiled bedding material run prior to anesthesia x Make a half-inch skin incision on midline, directly x Make sure animal is optimally hydrated over the spinal column, between the last rib and o Maintenance is approximately 100 mL/kg/day pelvis. x The skin incision can then be moved to the left or Procedure right side about 1 cm lateral to the spinal processes Ventral Approach to access the body wall. x Very similar to cat spay x Move the skin incision laterally to one side and x Approach by ventral midline incision bluntly dissect through the body wall. x Make a 1-inch incision between umbilicus and pubis x A large fat deposit is usually seen when dissecting x The cervix will be immediately visible in the incision through the body wall and the ovary sits within this x Follow uterine horn cranially to ovary fatty tissue. x Identify vessels in mesovarium and ligate x Exteriorize the ovary and the uterine horn and place o Hemoclips will speed procedure up, otherwise a hemoclip around the uterine horn prior to excising use 5-0 Maxon or PDS it. x Bluntly dissect along uterine horn x The body wall can be closed with a 5-0 Maxon or o Radiocauthery can be used on smaller uterine PDS or can be left open. vessels x Repeat the procedure on opposite side. x Repeat procedure on other side x Close skin with an intradermal suture pattern. x In all animals transection of uterine horn can be made cranial to cervix Follow-up x Will leave cervix behind and may provide an x Make sure animal is eating, urinating, and additional barrier against bacterial contamination defecating. from vagina x Recheck suture site frequently. x Close in a two- or three-layer fashion x Keep separate from other cage mates, as they o Use an intradermal suture pattern sometimes ‘groom’ suture out. o Apply lidocaine to suture site to decrease frequency of self-mutilation Common Complications x Suture removal by animal Dorsal Approach x Inadequate pain management often responsible for x Developed in lab animal medicine where self-mutilation ovariectomy is a common procedure x Ovaries and part of the uterine structures can be REFERENCES accessed dorsally 1. Capello V. Surgical techniques for neutering the x A dorsal approach offers a number of advantages to female rabbit. Exotic DVM. 2005;(7.5):15. the ventral approach 2. Johnson-Delaney C. Ovariohysterectomy in a rat. Exotic DVM. 2002;(4.4):17.

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