The dreaded downer cow (Proceedings)

"Downer" animal

Animal with prolonged recumbency (>12 hrs) that is persistent and intractable

Etiology

• Myriad of potential causes that include

o Infectious

o Metabolic

o Toxic

o Degenerative disorders

o Traumatic

• Not by any means an all inclusive list

Can be a considerable source of frustration

Evaluation/Approach

• History

o Reproductive status?

o Diet?

o Environment?

o Recent treatment

o Length of time recumbent

• Physical examination

o Visual before animal is approached

o Area around animal

o Signs of external trauma, riding, etc.

o Systemic analysis

• Heart rate, respiration, rectal exam

• Be thorough, but remember to first look for the horses, not the zebras

Categories

• Metabolic disease

• Mastitis

• Metritis

• Massive sepsis

• Musculoskeletal/neurologic disease

• Mystery

Severity and duration of above diseases determines whether an animal becomes a "downer"

Metabolic disease

• Hypocalcemia

o Cows that don't respond to IV calcium may have other electrolyte abnormalities ie: phosphorus

o May become downers due to lack of response, pressure necrosis or injury due to struggling to rise

• Hypokalemia

o Long-term treatment with corticosteroids may predispose to loss of K

• Hypophosphotemia

o Probably need lab work to definitively diagnose this

o Non-responsive milk fever

• Hepatic lipidosis

o Urine ketones, serum chemistry

• Nervous ketosis

o Urine ketones, serum chemistry

Mastitis

• Acute, endotoxemia due to gram negative bacterial infection (sometimes Staph.)

• Elevated heart rate, louder than that of milk fever

• May or may not have fever

• Edema and/or heat in affected quarter

• Milk is watery, serum like or blood tinged

• Can see this with gangrenous mastitis in initial stages

Metritis

• Distended uterus, possibly retained membranes

• Foul discharge, brown, watery

Massive sepsis

Peritonitits

• Hardware

• Ruptured abomasal ulcer

o Rectal temperature

o Tachycardia, pale mm, increased respiration

o Abdominal pain

o Decreased rumen activity

o Injected sclera

o Rectal exam

• Diagnosis

o Belly tap

o Ultrasound

Pneumonia/pleuropneumonia

• Probably down from pain or compromised lung function

o Malodorous breath

o Rebreathing bag may be helpful

Musculoskeletal/neurologic

Many potential causes

Difficult to define

• Difficult to examine

• Difficult to do neurologic exam

• May in fact be a result of primary disease

• Injuries from being recumbent (muscle crush, necrosis) may end up being reason they can't get up

Need to recognize catastrophic injury to prevent suffering

Systematic examination

Examination of rear limbs and pelvis

Start examination with uppermost foot

• Severe laminitis? Palpate, flex, extend digits

Region from P1 to stifle joint of uppermost limb

• Fractures

• Palpate joints, heat?, swelling?, crepitus in joint? Put limb through full range of motion

• Adduct, abduct limb – palpate medial and lateral aspect of joint

• Rupture of gastrocnemius tendon

o Occurs at junction of tendon and muscle belly

o Tendon remains relaxed when hock is flexed

o Even if unilateral, may not be able to rise

Stifle region of uppermost limb

• Rupture of cranial cruciate or collateral ligaments result in significant joint effusion

o Attempt internal rotation of tibia

o Palpate for widening of joint space

• Femoral nerve paralysis - dystocia

• Bilateral patellar luxation – hereditary?

Palpation of muscle masses of upper limb

• Crepitus? Swelling? Muscle tone?

• Pressure necrosis

Bones of pelvic region may best be evaluated by evaluating spatial relationship between:

• Greater trochanter

• Tuber coxae

• Ischium

With pelvic or femur fractures, may be a disruption of this relationship

Evaluation of coxofemoral joint

With one hand on greater trochanter, move limb through full range of motion

• Crepitus? – head/neck of femur, luxation of coxofemoral joint, stifle injury

• Does greater trochanter move in conjuction with rest of hind limb?

o If so, femur is likely intact up to greater trochanter

o If not, fracture?

o Excessive movement, coxofemoral luxation

Rectal exam

Coxofemoral luxation

• Compare length of limbs when in lateral

• Usually cranio-dorsal

o Can usually stand

o Disrupts spatial relationship

• Caudo-ventral or cranio-ventral

o Usually unable to stand

o Disrupts spatial relationship

o May rectally palpate femoral head in obturator foramen or cranial to brim of pelvis

Examination of fore limbs

Usually not in lateral recumbency, but if necessary to evaluate uppermost rear limb, might as well examine fore limb that is most available

• Not usually recumbent as a result of primary injury to forelimbs

• May have injury to radial nerve from pressure

• Dorsum of carpal joints may be abraded and become open wounds into joint

Examination of other side (downside)

Roll animal over and examine the up limb as described

Examination of vertebral column

Palpate dorsal spinous processes of thoracolumbar vertebrae

• Focal depressions, elevations, swellings

• Can be very difficult to assess

Fractures/subluxations

• Riding activity

• Chute injury

Degree of injury determines whether or not neurologic function is compromised

Can perform an evaluation of reflexes to evaluate neurologic function

To do reflex exam, need to roll animal back over (reflexes may be diminished after limb has been lain on)

• Flexor reflex – L 5 and 6 (withdrawal reflex)

• Patellar reflex – L 4 and 5, exaggerated in diffuse cord disease, or injury cranial to mid lumbar region, depressed if lesion is within L4 – L5.

• Tail tone, sensation – S 1

• Anal reflex, sensation – L6

• Perineal response – pinch skin, tail flexes, anus closes, animal "feels" it

Skin over thorax

• Cutaneous trunci

o 1 or 2 segments cranial to line where stimulus does not elicit a reponse

o May be normal to not have a response to stimulus applied to caudal lumbar area

Forelimbs

• Withdrawal reflex

o C6 to T2

Treatment

Clear area around animal

Deep bedding

• Sand

Frequent rolling/turning

Hobbles

Hip lifters

Floatation tanks