Downer Cow Syndrome

Also known as

Bovine secondary recumbency

Description

An animal becomes recumbent when it is unable to stand. A recumbent cow is often described as being down on the ground (sometimes for an obvious reason and sometimes for no apparent reason), and when she has been recumbent for a prolonged period is referred to as a downer cow.

Lateral recumbency refers to an animal lying flat on its side with head on the ground rather than with its head up; sternal recumbency refers to an upright animal resting on its breastbone with head up.

Recumbency (inability to rise up off the ground) in cattle is caused by a wide variety of metabolic, traumatic, infectious, degenerative, and toxic disorders. It might also be a recently calved cow that has suffered damage to nerves in the pelvic area that control the hind legs, or one that has a metabolic imbalance due to the sudden demands of lactation after calving.

The recumbent animal will often eat and drink and pass urine and feces, but makes no attempt to get up—though some will try to rise. Some will pull themselves around with their front legs and are referred to as creeper cows.

When trying to figure out the cause for the cow’s inability to rise, a veterinary examination is essential to rule out broken bones, nerve paralysis, milk fever, and other possibilities that need specific treatment.

If treatment of the underlying cause of recumbency is unsuccessful and cattle are unable to rise for more than 24 hours after initial recumbency, they may develop a secondary recumbency from pressure damage to muscles and nerves. This is often called “downer cow syndrome.” An alert downer cow does not show signs of illness or depression. She is able to eat and drink, and remains in sternal recumbency for no apparent reason. A non-alert downer cow is sick and depressed.

The main thing that happens during prolonged recumbency is pressure-induced death of muscle tissue (due to lack of blood circulation) of the thigh muscles, frequently affecting both hind legs.

Regardless of the initial cause of recumbency, all cattle that spend too much time lying down eventually develop damage to muscles and nerves of the hindquarters, especially when lying on a hard surface. Muscles of the leg the animal is lying on are compressed between the bones and the skin (and the hard surface) from the weight of the cow.

Cattle that cannot get up or walk may have a broken leg, severed tendons or ligaments, nerve paralysis, broken back, or metabolic problems. Downer cows are usually categorized according to possible diseases of the central nervous system—and listed as non-ambulatory cows with progressive or non-progressive neurologic conditions.

Complications of prolonged recumbency include acute mastitis, “bedsores” (pressure ulcers and death of tissues), and traumatic injuries to the limbs (laceration and rupture of muscle fibers in the thigh) from struggling and efforts to rise.

Sometimes a cow dies just because of problems arising from being down too long; muscle breakdown releases myoglobin (which can cause kidney failure) and potassium which can cause heart failure.

Signs

• Lying down
• Unable or unwilling to get up

Cause

There can be many possible causes, including trauma. The animal may have suffered an injury that makes it difficult or impossible for her to get up. Paralysis after calving is a common cause, but cows can also suffer bulling injuries (from a bull or another cow mounting her and injuring her back or hind legs) or severe fractures.

Hemorrhage and rupture of hind leg muscles may occur if the animal “spread-eagled” after falling down and struggling to rise on a slippery surface such as wet or icy concrete or a sheet of ice in the pasture or roadway.

The problem could also be due to post-calving complications, a metabolic issue (such as milk fever) or a disease such as mastitis or metritis (uterine infection).

A cow sometimes becomes a downer cow even when the initial cause resolves but she still doesn’t rise. This failure to get up off the ground usually occurs within the first 24 hours of the original cause, as a result of muscle and nerve damage due to heavy pressure on certain leg muscles and nerves.

The damage is often made worse because the cow was unable to shift position to prevent continuous bearing of weight on the same parts of her body. The longer these animals are down before the initial problem is resolved, the more likely they are to become downer cows.

After just 6 hours down, the muscles, nerves and joints are damaged and stressed from the constant weight and pressure—not being able to shift the weight or get up and reposition before lying down again (as a normal cow would do). About 2% of dairy cows that are treated for milk fever within the first six hours became downer cows, but if they are not treated for seven to 12 hours after the problem occurs, more than 25% became downers. If left untreated until 18 hours or more, nearly 50% are unable to rise.

Toxemia can be another cause—severe infections that make the animal weak or showing signs of shock. Mastitis, metritis and other toxicities can be causes of downer cows.

With prolonged recumbency, the lymphatic and venous drainage to the affected muscle is decreased because of sustained pressure with no decrease in arterial blood flow. The pressure-induced changes in blood flow cause an increase in fluid volume and pressure within the muscle, and swelling. In severe and prolonged cases of recumbency, the increase in intramuscular pressure is visible as a firm swelling of the muscle.

The resulting compression of muscles, nerves, and blood vessels within an enclosed space creates damage called compartment syndrome. The severity of pressure damage to the muscles depends on the areas of pressure (such as bones against muscles), duration of compression, and the surface on which the animal is lying.

The resulting muscle weakness in downer cows is often complicated by damage to and functional loss of the sciatic nerve and one of its branches. The sciatic nerve may be damaged by direct compression against the femur (largest leg bone, that joins the hip), secondary swelling of the surrounding muscles, or both. The degree of damage to the sciatic nerve is a critical factor for recovery of downer cows. Damage to that branch of the sciatic nerve results from direct pressure on the nerve as it crosses over the lateral condyle (one of the larger projections) of the femur.

It the cow had a long, difficult calving she may be exhausted as well as suffering pressure on the nerves to the affected hind leg. If she’s dull and listless she may be suffering from hypocalcemia (milk fever). Another likely cause of depression is toxemia, commonly due to a toxic infection in the reproductive tract or udder.

If footing is slippery, falling down and physical damage to the musculoskeletal system could be a possibility. This is much less likely to occur among cows in open spaces with a dirt or well-bedded surface.

Position of the hind legs may indicate the cause. Limbs splayed to the side, or out behind the animal may indicate nerve damage or paralysis, hip dislocation, or fracture of the femur or tibia. Fracture should be suspected if the upper limb is extended sideways so much that a crease is formed in the skin.

A thorough physical examination may be needed. If rectal temperature is lower than normal, the cow may be in shock. Eyes that appear sunken, or persistence of a skin pinch (a fold of skin pulled out at the neck or shoulder) for more than 2 seconds indicates dehydration. Pale mucous membranes may indicate toxemia, in which case the pulse may be weak and rapid. Respiration may be labored due to pressure of abdominal contents on the diaphragm.

If it’s a pregnant cow that has not yet calved, she should be checked to see if she might have a decomposing fetus. A vaginal check should also be done if she’s recently calved, to see if there is damage to and infection of the wall of the vagina. Metritis and associated toxemia can also cause postpartum recumbency.

Examination of the uterus via rectal palpation is important if the cow has recently calved. The degree of uterine involution should be appropriate for number of days postpartum. Fluid in the uterus or lack of proper uterine tone should be noted. Adhesions, lumps of necrotic fat, and enlargement or swelling of the cervix or vaginal wall can all be a result of a difficult birth.

Hip dislocations and fractures of the pelvis may be felt during an examination via the rectum, particularly if an assistant manipulates the upper limb of the down cow. Dislocation of the hip, or fracture of the femur should be suspected if the affected limb appears shorter than the opposite limb.

Pelvic fractures can be associated with sciatic nerve paralysis, whereas hip dislocation may result in some degree of obturator nerve paralysis. If either condition is suspected, the cow won’t have normal sensation in the lower leg. This can be evaluated by judicious and humane application of an electric prod to the lower part of the limb.

Examination of the udder should always be done if a cow is recumbent. A toxic mastitis infection can be a primary cause, but could also be caused by the recumbency itself, especially if the udder remains unmilked.

Prevention

Since nearly half of all downer cows are due to difficult calving, good management at calving can help prevent most of these situations, along with selecting bulls that sire easy-born calves. Cows should be in good body condition and on a well-balanced and adequate diet.

They should have a clean, dry place to calve, uncrowded. Calving cows should be monitored, and helped with the birth if necessary—with veterinary assistance if professional help is necessary.

Nearly 38% of downer cows are due to milk fever (low calcium) as the primary cause.  Preventing milk fever with proper nutrition and pre-calving management significantly reduces the number of downer cows. All dairy cows should be monitored closely around calving for early signs of milk fever.

Prophylactic administration of calcium to all cows, beginning with cows entering their second or later lactation, is beneficial in herds with a high incidence of milk fever.

In other situations, making sure cattle always have good footing, especially in breeding pastures, can often prevent injuries from cows being mounted and bred on steep hillsides, in bogs or swamps or other precarious terrain. Preventing ice flows across pastures in winter, and keeping cattle away from frozen creeks, rivers and ponds, can also avoid injuries from cows slipping and falling on ice.

Treatment

The treatment of a downer cow will depend on the cause.

If the cow is hypocalcemic (low on calcium) after calving, and does not respond to calcium therapy (still cannot get up), phosphorus, magnesium, and potassium should be given as additional treatments pending results of laboratory tests. Monitoring the blood mineral status is an important part of downer cow management.

In most cases, recovery depends on good management and nursing care. Lateral recumbency (flat on her side) must be corrected immediately to avoid regurgitation and inhaling of stomach contents. The animal should be rolled into sternal recumbency (upright, with head up). To keep the cow upright, the limb on which the animal has been lying should be pulled from under the body. If she was lying on her left side, she should be rolled into sternal recumbency on her right side. Support with something like a straw bale placed under the shoulder may be necessary for some animals to remain upright.

Attempting to stabilize a recumbent cow on a concrete surface is not a good idea, but sometimes unavoidable. Bedding the area around and under the cow with wet manure to a depth of about 6 inches is a common practice, spreading at least 10 inches of dry straw over the wet mass.

If the cow struggles and scrapes into the wet manure, exposing concrete, more manure and straw must be added. The manure/straw pack provides better footing than concrete if she does try to get up, but also may soil the skin with urine and manure.

Dermatitis and/or mastitis can result from contamination. A bed of sand about 10 inches deep is better. This usually drains well, and stays cleaner, if the manure from the animal is removed several times each day.

Every day that she’s down, an attempt should be made to help her get up.  Sometimes simply “tailing” her up (grasping the base of the tail and lifting--to stimulate her to try to rise) and then steadying her will work. Even helping her stand for a short time will take pressure off compromised limbs and also encourages the cow to try again on her own.

One method, for a cow that won’t try to rise, involves standing with your feet pressed under the front of the cow at a point below the joint between the shoulder blade and the humerus. A sharp blow is delivered by driving your knees into the muscle mass below and to the rear of the shoulder blade. This method must not be used on the chest wall (which is unprotected by muscle mass), or you might fracture the ribs. If the animal struggles to rise in response to the sudden startling blow, an assistant should grasp the root of the tail head with both hands and lift. Lifting on any other part of the tail may damage it.

Hip clamps (to raise the cow with a tractor loader) can be helpful, but proper use requires experience, skill, and a delicate touch. Continual use of hip clamps causes trauma and pain.

If the cow is being held up by the tractor loader (unable to support her weight on her front legs), she should also be supported with a canvas sling under the sternum (as well as the hip clamps). The forelimbs support 60% of a cow’s weight; if she is unable to bear weight on her front legs, a sling is necessary.

A chest band is needed, to keep the sling from slipping backward onto the belly area. If the sling is suspended from the tine at one end of a fork lift, and the hip clamps from a tine at the other end, this usually works, with minimal trauma to the cow.

If a fork lift is not available, a T-bar suspended by a pulley from an overhead beam in a barn (or a tripod for a cow out at pasture) will work. The jaws of the hip clamps must be well padded, using like synthetic foam or rubber secured in place with duct tape.

Hip clamps should not be applied too tightly and the cow should be lifted slowly to allow time for blood circulation to return to the limbs. She should be lifted until her hind feet barely touch the ground. Often, a cow will hang with the limbs slightly flexed.

To get her to bear weight on them, a person on each side of the cow can press on a shoulder while facing the hind end. Once the front legs are straight enough to bear weight, the cow is slowly lowered as assistants attempt to force each hind leg into a weight-bearing posture. As soon as any weight is supported by the two hind legs, the device should be lowered 1 to 2 inches so she is actually bearing some of the weight on her own.

Even if the cow does not stand, the lifted position provides an opportunity to manipulate and massage the limbs, check them for damage, and do vaginal and rectal examinations if needed. You may have to put the cow back down, but raising her periodically can help her heal and give her encouragement to try to get up on her own.

A down cow should be provided with clean water. A shallow rubber tub minimizes risk for spillage. If the cow won’t drink, she must be given fluid by drench or stomach tube.

The downer cows most difficult to treat are those won’t eat. It’s best to try to tempt her with a little fine, palatable forage (fresh green grass, or fine, leafy alfalfa) than try to give her a big feeding at once.  If she slobbers on the feed, she won’t eat it later. Clear away any uneaten feed and give her new fresh feed frequently.

If she is unable to eat, she can be fed by stomach tube. Blended up pellets, such as alfalfa pellets (presoaked so they will go through a blender) mixed with several gallons of water can be administered by stomach tube a couple times a day.  If she has lost her cud, she can be drenched with rumen contents to get the proper “gut bugs” going again.

It is important to roll the cow from one side onto the other every few hours to prevent muscle damage to her hind legs. If they are already damaged due to trauma (from falling down or legs splayed out), anti-inflammatory medication can help reduce pain and minimize swelling of the muscles, and make the cow more comfortable.

Hobbling the hind legs together may be necessary if she injured them in a splayed-out position when she fell down or was struggling to get up, or if she might have suffered obturator or sciatic nerve damage in attempts to get up. You need to keep her hind legs from splaying out sideways again if she attempts to rise—to prevent more muscle damage.

Ropes tend to cut into the tissue and shut off circulation; it’s better to use a wide, soft nylon strap--wrapped twice around the middle of each lower leg, allowing a distance of about 3 feet between the legs, depending on size of the cow.

If she is outdoors and weather is cold and windy, she needs protection to keep her from being chilled, especially if she is already in shock. A windbreak of straw bales or even a hut with straw bale walls and a tarp roof over her can be very helpful.

Straw bedding may also be needed if the ground is cold, and will also give her some cushion. Even if weather is warm and she doesn’t need shelter, panels should be put around her if there are other livestock in the pasture, to keep them from bothering her or consuming her feed/water.

Although a cow may sometimes get up after being recumbent for 2 or 3 weeks, this does not imply that she should be left for this length of time. As long as she looks bright, occasionally struggles to rise, and continues to eat and drink, recovery is possible. If the cow becomes listless, shows no interest in feed, or has “bedsores” or is losing weight, slaughter on humane grounds should be considered.

Some recumbent cattle seem to give up, and lose interest in trying to stand; these cattle may benefit from use of a specially designed flotation tank. The animal is loaded into the flotation tank by being pulled into the empty tank on a mat. Waterproof doors are then closed, and the tank is filled with lukewarm water.

The animal should be encouraged to stand once the water reaches mid-shoulder level. Cattle that can support their own weight should be permitted to stand for 6 to 8 hours, but the water in the tank should be removed as soon as they start trembling (from muscle fatigue).

If a cow remains standing she can be encouraged to walk slowly from the tank on a nonslip surface.

Cattle that can walk out of the tank after the first flotation treatment are 4.8 times more likely to survive than those that do not walk out. Cattle that stand on all four limbs during the first flotation treatment are 2.9 times more likely to survive than those that had an unbalanced stance or were unable to stand. Reported success rates in returning recumbent cattle to normal ambulation using a flotation tank range from 37%–46%.

If a cow has just calved—with a difficult birth—get her up as soon as possible. If there has been some stretching and nerve damage it will be worse the longer she lies there.
Recently calved cows can often be motivated to rise if they hear their new calf bawling or if you smear birth fluids over their muzzle and get them thinking about the calf.

Judicious use of an electric prod applied once under the tail may stimulate her to try to get up, and this is more humane than beating on her. If she is wobbly when she attempts to get to her feet (if one leg is useless because of the nerve pressure), steady her by hanging onto her tail and helping her balance, until she can stand more easily on her own.

Usually once a cow gets up (if she hasn’t been down very long after calving) and is helped to stay standing for a while, she will recover rapidly—whereas if you leave her lying there, she may not be able to get up.

If a cow is on concrete and can’t get up, the chances of resolving the problem are enhanced by moving her to a location with an earthen floor. In warm, dry weather, the best location for a recumbent cow is grassy pasture, although this means that a method to lift the cow must be readily available.

Otherwise, the location selected should have a roof and protection from bad weather. This might be a hay barn or implement shed, which may have the added benefit of allowing creation of a pulley system to lift the cow.

Moving the cow to a different location requires rolling her into her side. The cow can then be slid over dry straw for a short distance by pulling on a rope attached to a lower forelimb and a halter rope.

Transportation over longer distances can be accomplished using a suitably prepared “stretcher” such as a metal gate hauled by tractor. The gate is placed close to the back of the cow while she is lying on her side.

A tarp can be placed on the gate to protect the cow from contact with the ground, with straw spread over the tarp, and the cow is then rolled over onto the makeshift stretcher.

Her halter should be tied to the gate to minimize struggling, and a blindfold placed over the eyes to minimize alarm while she is being moved. Her tail can be tied to the hock of the upper limb. Care must be taken to avoid injury to the udder, ears, and tail.

Once moved, she can be rolled off the gated and positioned upright (sternal recumbency). Some cows, especially if they are down for less than 12 hours after calving, will get up immediately after being moved to a location with good footing.

Recumbent cattle should be examined daily to determine any change in ability to rise or bear weight. The chance of improvement is low if a cow does not show any improvement within 5 days of moving to a location with good footing and correction of any metabolic and mineral imbalances.

With milk fever, the critical issue seems to be the length of time from when clinical signs begin until treatment. Every cow that has been successfully treated for hypocalcemia should, if necessary, be moved to a location with a good footing and remain there for 48 hours. Straw over sand provides good insulation and good footing.

If the cow is lactating, she must be milked if she is down for more than 12 hours, to reduce mastitis risk.