UTERINE PROLAPSE

Etiology

In dairy cattle, the condition is not thought to be inherited and seldom recurs in subsequent parturitions. Although the exact cause for an individual patient may be difficult to determine, predisposing causes include dystocia, tenesmus, and hypocalcemia. Primiparous cows can be affected, but pluriparous ones are probably at greater risk. Prolapse of the uterus also is fostered by confinement, lack of exercise, and gravitational effects when cattle are allowed to calve with their hindquarters lower than their forequarters, as happens when confined cows calve into the drop of conventional barns. Uterine atony is the common inciting cause and is frequently associated with hypocalcemia in multiparous dairy cattle.

Prolapse usually occurs within hours of calving and almost always within 24 hours of calving. Instances of uterine prolapse occurring several days following calving are cited by many practitioners but are extremely rare.

Clinical Signs and Diagnosis

The clinical signs are dramatic and suffice for definitive diagnosis. Occasionally neophyte handlers or those privileged to have never seen the condition will confuse uterine prolapse with vaginal prolapse, but the sight of a fully prolapsed uterus is difficult to confuse with other conditions. Conspicuous placentomes on the exposed endometrium make the prolapsed uterus impossible to confuse with any other organ. The cow may appear healthy otherwise; this is often the case in primiparous cattle. Pluriparous cows with uterine prolapse often show varying degrees of hypocalcemia such as weakness, depression, subnormal temperature, anxiety, struggling or prostration, and coma. Tenesmus is common to most cases. Signs of shock should be differentiated from those of hypocalcemia because a small percentage of prolapse patients may develop hypovolemic shock secondary to blood loss (internal or external), laceration of the prolapsed organ, or intestinal incarceration within the prolapsed organ. Extreme pallor, a high heart rate, and prostration are grave signs in such cattle. Rarely the cow is found dead, especially when an unobserved calving has occurred. The prolapsed uterus often is heavily contaminated with bedding, feces, dirt, and placenta. Some bleeding is common from exposure injuries to the placentomes or endometrium. If the affected cow is able to stand and walk, the massive organ hangs near the hocks and can be stretched, traumatized, or lacerated as it fl ops back and forth against the rear quarters.

Treatment

Uterine prolapse is one of the true emergencies in bovine practice, and rapid owner recognition followed by prompt veterinary treatment greatly improves the prognosis.

When notified of the condition, the veterinarian should instruct the owner to keep the cow quiet and to cleanse the exposed organ and keep it moist. Warm water containing dilute (1%) iodine and a clean towel or sheet work well for this purpose. If possible, the owner also may be instructed to elevate the organ to the level of the ischium or higher to relieve vascular compromise and subsequent edema, as well as lessen the chance of injury. When the veterinarian arrives at the scene, overall assessment of the situation is in order before proceeding with specific treatment. The cow’s position, overall physical status, and the environment should be assessed. Specifically:

1. Can the cow’s position be altered easily given the available help and environment to provide a mechanical advantage for replacement?
2. Is the cow hypocalcemic? Would correction of the hypocalcemia be beneficial immediately, or can it wait until after replacement of the organ? Would the cow be more likely to stand if treated with calcium? Some practitioners prefer replacement with the animal standing; others do not. Calcium treatment increases uterine tone and makes it substantially more difficult to replace; deferment until after uterine replacement is preferred if the cow can withstand the delay.
3. Is the cow in shock? If so, the owner should be made aware of the poor prognosis, lest veterinary treatment be blamed for her death during or after treatment.
4. Is footing adequate to allow the cow to stand, or should moving the cow to better footing be considered?

This overall assessment and a very quick history and cursory physical examination can be completed within minutes and may improve the end results greatly.

Specific treatment is subject to great individual variation as regards when to administer calcium, whether to perform the repair with the patient recumbent or standing, when to give certain drugs, and aftercare. The basic premises are, however, agreed on by most practitioners.

1. An epidural anesthetic is administered to relieve tenesmus and avoid fighting with the cow during replacement.
2. The cow is positioned to the veterinarian’s advantage.

The cow already may be able to stand, or the veterinarian may choose to treat the cow for hypocalcemia and allow her a short time such that she may stand for the procedure. Recumbent cows on a fl at surface that have the hind legs pulled behind them so they are in sternal recumbency and the hind legs pulled caudally so the animal lies on the cranial stifle areas are easier to correct, but this position may predispose to coxofemoral injury if the cow struggles to get up. This tips the pelvis forward and allows a mechanical and gravitational advantage. If the cow is in an uneven posture, it also may be possible simply to angle her front end downhill to give significant mechanical advantage.

In difficult situations where labor is unavailable or the environment is not conducive to gaining a mechanical or gravitational advantage, hip slings can be used to elevate the cow’s rear quarters to hasten replacement. In some cases it may be possible to hoist the hindquarters of the cow using farm equipment such as a skid steer.

While this does facilitate replacement of the uterus, care must be taken to support the uterus as the cow’s hindquarters are raised. Excessive tension on the prolapsed uterus may result in rupture of the uterine artery, already compromised by stretching in the prolapsed organs.

3. The uterus should be elevated to at least the level of the ischium to relieve vascular compromise and edema. One or two assistants can do this by suspending the organ in a towel, sheet, or prolapse tray when the cow is standing. In recumbent cows, the assistant can sit on the cow’s sacral region facing backward and elevate the organ by holding it in his or her lap or suspended by a towel.
4. The uterine surface should be gently and thoroughly cleaned of debris and dirt and the placenta removed carefully. Usually the edematous placentomes allow easy separation of cotyledons from caruncles. Dilute antiseptics can be added to the water used for this purpose and the organ protected from further contamination. During this cleansing, gentle pressure and kneading of the organ are helpful to start restoration of uterine tone and relieve edema.
5. Systemic injection of oxytocin or ergonovine before replacement is controversial. Some practitioners will administer these tonic drugs before replacement— especially when the uterus is completely flaccid, atonic, or edematous, and the risk of iatrogenic perforation during replacement is deemed a considerable risk. Others prefer to administer tonic drugs following replacement for fear that the contracting organ will become more difficult to replace and cause greater resistance.
6. After the cow is positioned and the organ cleansed, replacement begins by slowly kneading and pushing the organ starting at the cervical end nearest the vulva. Lubrication with mild soaps and water or obstetrical lubricants is essential to facilitate these manipulations. Glycerol, if available, makes a useful lubricant because it is also hydroscopic and reduces uterine edema. The veterinarian must be careful not to push fingers through the friable endometrium or uterine wall; cupped hands work best. If iatrogenic uterine tears occur, they should be sutured with an inverting pattern. Candid discussion with the client regarding salvage should be undertaken when significant abdominal contamination is deemed to have occurred through uterine tears acquired following prolapse. Individual caruncles must be eased through the vulva, and rest periods during extreme tenesmus may be necessary. A slow, gradual replacement usually ensues until only a portion of the gravid horn remains exposed.

At this time, the tip of the horn is identified, and hand and arm pressure is exerted to evert the horn and uterus completely back into the abdomen. Once everted, the organ should be rocked gently and shaken to ensure complete eversion of the horns and minimize the chances of reprolapse.

Some practitioners also use a bottle as an “arm extension” to aid in complete eversion of the horns. It is very important to completely evert both gravid and nongravid horns to prevent tenesmus from causing reprolapse after the epidural wears off.

7. Oxytocin or ergonovine is administered systemically and the organ palpated further to assess the response (e.g., increased tone). Intrauterine antibiotic therapy may be administered, and systemic antibiotics such as penicillin or ceftiofur should be used for 3 to 4 days to counteract the anticipated metritis. The cow should not be allowed to lie with her hind end “downhill” or in a gutter. Hypocalcemic cows not treated before replacement should be given appropriate calcium.

Retention sutures placed in the vulva following replacement of uterine prolapses are also controversial. They are ineffective for prevention of reprolapse and may rarely mask the condition by allowing the uterus to become trapped in the vagina. Since the common predisposition for uterine prolapse is uterine atony, complete restoration of the uterus to its normal position and treatment to enhance uterine tone are sufficient to prevent recurrence of the condition.

Prognosis

The prognosis for uncomplicated uterine prolapse is good, and most cows that respond promptly will breed back following routine monitoring and treatment of their metritis. Furthermore, dairy cows that have had prolapses do not have a higher incidence of the problem at future calvings. Of cows with uterine prolapses, 75% or more should do well.

Of cows that do not do well, a low percentage will reprolapse within 1 to 3 days, some cannot be replaced at all, some die as a result of intestinal incarceration in the prolapse or bleed out, some develop severe peritonitis or perimetritis from uterine tears, and some do irreparable damage to the prolapsed organ. The owner should be made aware that the cow could die at any time during or following replacement when shock is obvious. Reprolapse is an extremely bad sign, and cows that repeatedly prolapse after initial correction seldom do well. It is wise to reexamine all prolapse patients 3 days after repair to assess the overall systemic state and make specific recommendations regarding metritis or uterine injury. Decisions on further antibiotic and other therapy can be discussed with the owner at this time.