Spaying in Rats

By Gregory Rich, DVM; Laurie Hess, DVM; Rick Axelson, DVM

What is an ovariohysterectomy?

An ovariohysterectomy is often referred to as a spay or spaying. It is a surgical procedure in which the left and right ovary and both left and right horns of the uterus are removed completely, to sterilize or render a female animal infertile. Some veterinarians will perform an ovariectomy, in which just the ovaries are removed.

Why should I have my rat spayed? 

There are many behavioral and health benefits associated with spaying your rat.

  • The obvious benefit is the elimination of unwanted pregnancy if your female rat is housed with male rats. Although raising baby rats might be a wonderful family experience, finding homes for the new rats might prove more challenging than you anticipate, and un-spayed rats breed often! Females can give birth to 7-20 babies at a time. They can also reproduce within days after giving birth.
  • Spaying at an early age completely negates the risk of ovarian or uterine cancer and significantly minimizes the risk of breast and pituitary gland cancers in rats. Breast cancer is extremely common in pet rats.
  • Once the uterus is removed, there is no chance of the rat developing a uterine infection (pyometra) or a uterine tumor.
  • Spayed rats are much less likely to display undesirable, hormone-induced behaviors such as mounting and aggression.
  • Spayed rats may be calmer and easier to handle, as they are not experiencing the stresses of sexual frustration.

When should I have my rat spayed?

Ideally, most rats are spayed between four and six months of age. The older the rat, the longer its body is exposed to hormones produced in the ovaries, and the greater the chance of developing mammary gland cancer.

What does spay surgery involve?

This surgical procedure is done under general anesthesia. Rats are typically not fasted the night prior to surgery, as is done with most dog and cat surgeries, because rats are grazers, rather than meal eaters, and their metabolism and digestion are much faster than that of most larger mammals.

Your veterinarian will perform a physical examination on your rat before the surgery and may recommend pre-surgical blood tests. These blood tests allow your veterinarian to assess your rat’s overall health, ensuring that your rat is a good candidate for anesthesia. If preanesthetic bloodwork shows any abnormalities, these abnormalities can be addressed by making adjustments to your pet’s pre-surgical or post-surgical treatment plan.

The operation is performed through a small incision into the middle of the abdomen, on the underside (ventral aspect) of the abdomen. Before surgery, the hair in this area will be shaved and the skin cleaned with antiseptic solution.

Both ovaries and the entire uterus are removed. If an ovariectomy is performed, in which only the ovaries and not the uterus are removed, there will be a small incision on either side of the rat, just behind the last rib. The surgical incision will be closed with several layers of fine, absorbent, suture material that dissolves and does not need to be removed. Most rats go home 24-48 hours after surgery.

What post-operative care will my rat need?

Your rat will likely be given pain medication in hospital and may be sent home with several days worth of the same medication if deemed necessary. Keep your pet in a clean, quiet environment and try to minimize excessive running, jumping, or hard play that may compromise healing of the incision. Separate this rat from any others at home for 5-7 days to minimize chewing or excessive cleaning of the surgical site by the other rats.

Offer food as usual, as a rat should be eating and drinking normally within 12-24 hours of the operation. If your rat is not eating well, you may need to syringe feed according to your veterinarian’s instructions.

Inspect and assess your rat and the incision several times daily and report any concerns about behavior changes, appetite, drinking, urination, and defecation to your veterinarian. Occasionally, rats will chew at the surgical site and open the surgical wound. This needs immediate veterinary attention. Otherwise, your veterinarian may want to check on the healing of your rat’s incision 7-10 days after she goes home.

Are complications common with spaying?

Complications are rare with this surgery. However, as with any anesthetic or surgical procedure, in any species, there is always a small risk associated with being anesthetized. To minimize risk, it is important to follow all your veterinarian’s preoperative instructions and to report any signs of illness or previous medical conditions to your veterinarian prior to the day of surgery.

Potential complications may include:

Anesthetic reaction: Any animal may have an unexpected adverse reaction to any drug or anesthetic. These reactions cannot be foreseen but are extremely rare.

Internal bleeding: This may occur from cutting and manipulating internal organs and blood vessels. Postoperative internal bleeding is very rare and is more likely to occur if your rat is too active in the days following the surgery. Signs to watch for include weakness, pale gums, depression/listlessness, lack of appetite, or a distended abdomen. If you see any of these signs in your rat, she should be checked by a veterinarian immediately.

Postoperative infection: Although rare, this may occur internally, where organs and blood vessels were handled, or externally, around the incision site. Infection typically can be managed with antibiotics and applying warm compresses to the incision if it is swollen. Infections most commonly occur when the pet licks the surgical site excessively or is kept in a damp, dirty environment. Monitor the surgical site several times daily for swelling, redness, reopening, and the presence of pus or other discharge.

Suture reaction or sterile abscess formation: This is extremely rare but occurs in some animals that have a reaction to certain types of suture material used during surgery. Their tissues react to the suture and often develop draining wounds or tracts that may appear up to several weeks after the surgery was performed. Further procedures may be required to remove the suture material and correct the issue.

Will spaying have any adverse effects on my rat?

Most rats will experience no adverse effects following spaying and spaying is generally recommended for all healthy, young rats to prevent future health problems. There are many myths and beliefs about spaying that are not supported by facts or research. If fed a proper diet, your pet rat will not become fat and lazy after being spayed.

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