Bovine Secondary Recumbency

The objective of the physical exam in a downer cow is to determine the current status of the animal rather than only to assess the primary cause for the recumbency. In cows that are involuntarily recumbent for >24 hours, secondary damage should be not only considered but expected.

The examination should be preceded by determination of the patient's signalment, including age, stage of lactation, body condition, and production type; and by acquisition of a concise history relevant to the case. The history should include information about the circumstances under which the animal became involuntarily recumbent, in cases of periparturient animals the nature of parturition, the duration of the recumbency, prior treatment, and treatment response. A herd history may be relevant in herds with higher incidence rates of downer cow syndrome.

The physical examination begins with a visual examination of the patient from a distance to determine respiration rate and type, and to assess demeanor and mentation, appetite, extent and type of mobility while recumbent, the position of the limbs, and the presence of swellings or wounds. The area surrounding the recumbent animal should be inspected for signs of unsuccessful attempts to rise, and to determine whether the recumbent cow was able to tilt herself (or was tilted) from one side to the other.

The next step is a general physical exam to determine hydration status (based on eyeball recession or skin-tenting duration), both body surface temperature and rectal temperature, heart rate, pulse strength, jugular fill, and capillary refill time, which could indicate varying extents of hypovolemia or hypovolemic shock. The abdomen should be palpated and auscultated to identify abnormal content or motility of the digestive tract or abnormal muscle tone of the body wall that may suggest an acute abdomen. In female recumbent cattle, inclusion of the mammary gland in the exam is imperative. A toxic infection of the udder caused by an organism such as Escherichia coli or Klebsiella pneumoniae can be a primary cause of recumbency. However, such an infection may be precipitated by the recumbency, especially if the cow is bedded on an unsanitary surface and the udder is engorged and remains unmilked.

Vaginal exploration is mandatory in every peripartum, recumbent cow. Damage to and infection of the wall of the vagina is common. Metritis and an associated toxemia can contribute to postpartum recumbency.

Rectal exploration is essential for differential diagnosis. For convenience, it is advisable to combine the rectal exam with the musculoskeletal examination of the hind limbs (see below). Before initiating the rectal exploration, the tone of the tail and anal sphincter should be assessed. Decreased or absent tail and sphincter tone suggest damage of the nerve bundle extending from the caudal end of the spinal cord, a condition termed cauda equina syndrome. In cases of suspected cauda equina syndrome, particular attention must be paid to the size and tone of the urinary bladder during rectal exploration because this syndrome can be associated with paralysis of the urinary bladder. At least small amounts of fresh feces should always be present in the bovine rectum. Palpating the bony circumference of the pelvis to identify fractures, swellings, or dislocations is easily done in nonpregnant animals; it may be challenging, however, with a pregnant or freshly postparturient uterus in the pelvic cavity. In these cases, having an assistant move the pelvic wings from outside in a rocking motion while the pelvis is palpated transrectally will allow determination of the presence of crepitation or abnormal motility in the pelvis in the case of a pelvic fracture. Palpation of the obturator foramen on both sides of the bottom of the pelvis may reveal the presence of the head of the femur in one of the foramina in cases of a ventral or caudoventral dislocation of the hip. Palpation of the obturator foramen is easily done when the uterus is small; in late pregnant or periparturient cows with a large uterus, this examination is better conducted transvaginally. The abdomen should be further explored rectally to rule out abnormalities of the digestive tract or signs of peritonitis.

The extent of uterine involution should be appropriate for the number of days postpartum. Ballottement of uterine fluid or lack of tonicity should be noted. Unexpected anomalies may be palpated. Adhesions, lumps of necrotic fat, and enlargement or turgidity of the cervix or vaginal wall are all sequelae of a difficult birth.

Next follows an in-depth examination of the musculoskeletal system. With the cow in sternal recumbency, the back should be firmly palpated from the neck to the tail to identify swellings, painful areas, possible misalignment, instability, or abnormal motility of the vertebrae. The patient should then be rolled into lateral recumbency with an assisting person keeling on the neck, and fore limbs and hindlimbs of the upper side then carefully examined from toe to hip or shoulder. Examination should confirm the musculoskeletal integrity of the limb with normal mobility of joints, and should identify painful areas, swellings, or open lesions.

Muscle bellies must be deeply palpated to identify swelling, edema, or abnormal firmness that may indicate compartment syndrome. The nerve supply down to the lower limb should be tested by stimulating the flexor-withdrawal reflex, first by pricking the skin above the coronary band on the dorsal and plantar/palmar side with a hypodermic needle. If the animal does not respond, an electric cattle prod should be briefly held to the distal limb to determine whether the stronger stimulus can elicit a response. This test with a stronger stimulus enables differentiation between decreased and absent sensitivity in the leg. The cow should then be rolled back into sternal recumbency and into lateral recumbency of the other side to repeat the examination on the contralateral side.

In alert downer cows, if the physical examination to this point has not revealed an apparent cause for recumbency, motor activity should be tested by stimulating the recumbent animal to make an attempt to rise. Several simple but effective techniques can be tried for this purpose. In one method, the clinician, while standing, presses their feet under the cow below the scapulohumeral joint. They then deliver a sharp blow by driving their knees into the muscle mass below and caudal to the scapula. It is important not to use this method on the thoracic wall unprotected by the muscle mass, because it could fracture the ribs. If the animal has difficulty rising, an assistant should use both hands to grab the root of the tail and lift. Damage could result if any other part of the tail is grabbed for this lifting maneuver. The sound of a cow's own calf bawling with hunger could motivate a recently calved cow to rise. The calf is best restrained close to the cow but out of the cow's sight.

The motion, weight bearing, and positioning of the limbs during the attempt to rise must be observed closely. Abnormal weight bearing, positioning, and posture of a limb can provide valuable information for locating a specific lesion. If the attempt to rise is unsuccessful and lacking diagnostic value, the cow should be rolled onto the opposite leg and the procedure repeated. In cases of unilateral nerve, muscle, tendon, bone, or joint trauma, a recumbent cow may be able to rise only if the unaffected limb is underneath it.

Whenever the circumstances permit to do so safely, the patient should be lifted using a device suitable for this purpose, with the objective of completing the motor function examination. If hip clamps are used, they should not be too tight, and the cow should be lifted slowly so that circulation of the limbs can be reestablished. The device should be raised until the cow is lifted enough that its hind feet just touch the ground. Often, the cow will hang with the limbs slightly flexed. This slight flexion should not be confused with unilateral flexion, which indicates peroneal paralysis. Next, two assistants—one on each side of the cow and facing the hind limbs—should press the shoulders into the paralumbar fossa. The lifting device should then be lowered slowly while the assistants try to force the hind limbs into a weight-bearing posture and to manipulate the stifle and hock to decrease the flexion. As soon as the two limbs are supporting any weight, the device should be lowered 1–2 in. This process may have to be repeated several times.

In this part of the exam, particular attention should be paid to the contributing effort the cow makes while lifted, to the amount of weight bearing by each individual limb, and to hints of possible proprioceptive deficits suggestive of specific nerve lesions. Regardless of whether the cow stands, while it is lifted its limbs can be manipulated and palpated for crepitation, and the skeleton in the pelvic area can be evaluated for possible asymmetry.

Asymmetrical position of the greater trochanter of the femur of both sides, combined with abnormal motility of the trochanter while moving the corresponding limb, suggests a dislocated hip. If the affected limb appears shorter than the contralateral limb and the greater trochanter does not move while the affected leg is being moved, there may be a fracture of the femoral neck or proximal femur.

Ischemic necrosis and rupture of muscles of the thigh region are common necropsy findings in downer cows. Hemorrhage and rupture of adductor muscles may be evident if the animal “spread-eagled” itself while struggling to rise on a slippery surface such as wet or icy concrete. Traumatic and inflammatory injuries to sciatic and peroneal or tibial nerves are also found in downer cows. Damage to intrapelvic nerves, such as the sciatic and obturator nerves, account for most cases. Decubital injuries to the lateral aspect of the stifle can be associated with damage to the peroneal nerve.

The value of hip clamps is controversial. Their proper use requires experience, skill, and a delicate touch. Continual use causes trauma and pain that is counterproductive. The forelimbs support 60% of a cow’s weight; therefore, the use of a canvas sling under the sternum is almost mandatory for consistent success. A chest band is required to prevent the sling from slipping backward. Suspending the sling from the tine at one end of a forklift and the hip clamps from a tine at the other end minimizes trauma. If a forklift is not available, a T-bar suspended by a pulley from an overhead beam (or a tripod for animals at pasture) will serve. The jaws of the clamps must be well protected with synthetic foam or rubber secured in place with a wrap of duct tape.

Moving a downer cow requires rolling her into lateral recumbency. 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 farm gate hauled by tractor. The longest dimension of the farm gate is closely applied to the back of the cow still in lateral recumbency. A tarpaulin is placed on the gate to protect the cow from contact with the ground. Dry straw is spread on the tarpaulin, and the cow is rolled over onto the makeshift stretcher. The halter should be tied to the gate to minimize struggling, and a sack placed over the eyes to minimize alarm while the cow is being moved. The tail is best tied to the hock of the upper limb. Once moved, the cow should be restored to sternal recumbency. A few cows, particularly if <12 hours postpartum, will rise immediately after being moved to a location with good footing.

Dragging a recumbent cow over the floor without protection for body and skin or carrying the cow while it is hanging on hip clamps is inadmissible because these procedures are likely to inflict additional physical damage and pain on the animal. Moving injured cows in such a manner not only is illegal in many countries but also hurts the production animal industry through negative publicity.

Recovery from downer cow syndrome strongly depends on the quality of patient management and nursing care. Moving the cow to a site with an earthen floor improves the changes of resolution considerably. The optimal site depends on climatic conditions. If the weather is warm and dry, grassy pasture is best, but a ready means to lift the cow is essential. In less ideal weather conditions, a shelter with a roof and other protection should be provided. Hay barns and implement sheds can provide the necessary protection, and it may be possible in such structures to install a pulley system to lift the cow.

Protection from the elements is essential. Rain and wind can decrease body temperature considerably and worsen shock if present. A windbreak of straw bales is essential. Straw bedding should be provided to help insulate the cow from the ground. A recumbent cow does not require a warm environment; in a cold environment, however, an inactive animal can gradually succumb to hypothermia.

Lateral recumbency must be avoided. If it occurs, immediate correction is required to prevent bloating, regurgitation, and aspiration of gastric contents, as well as pressure lesions to the brachial plexus and radial nerve. The cow should be rolled into sternal recumbency. To maintain this posture, however, the limb the cow was lying on should be drawn from under the body. For example, a cow presented in lateral recumbency on the right side should be rolled into sternal recumbency on the left side. To maintain sternal recumbency, some animals may require support under the shoulder; straw bales can be used for this purpose. Tilting the recumbent cow in 6- to 8-hour intervals from one side to the other is labor-intensive but of paramount importance to limit secondary pressure damage to muscle and nerves. This repeated tilting defines state-of-the-art nursing care for downer cows.

Attempting to stabilize a recumbent cow on a concrete surface is highly undesirable but sometimes unavoidable. Until the transport of the recumbent cow onto a softer surface with more grip can be arranged, the cow's rear legs should be hobbled to prevent slipping and splaying during an attempt to rise. A common approach is to bed the cow on a layer of least 10 inches of dry straw sitting on top of >6 inches of wet, sticky bedding (feces). If the concrete beneath the wet layer becomes exposed by the cow's movements, more must be added. Although the footing is good with such a manure pack, the cow's skin may become soiled with urine and feces. A deep bed of sand (> 25 cm) is more effective for housing a recumbent cow. A sand bed usually drains well, and good hygiene can be maintained if voided feces are removed several times a day.

The downer cows most difficult to treat are those that do not try to eat. A cow that salivates on its feed will not eat it later. Rather than being offered large amounts of feed, the cow should be tempted with sweet hay. Any hay not accepted should be cleared away every 30 minutes. Placing bitter-tasting weeds such as ivy or dandelion in the cow's mouth may provoke salivation and an interest in eating. Some cows accept lettuce and cabbage leaves. In extreme cases, the cow can be drenched with rumen contents.