Identification and Causation of Lameness in Cattle

Question 1

describe normal bovine hoof anatomy (4)

Answer 1

1. cloven hoofed:
   -front feet: medial claw is slightly larger
   -rear feet: lateral claw is slightly larger
2. corium produces the hoof horn tissue which becomes keratinized
3. sole on the surface of the hoof is also produced by corium and joins hoof wall at white line
4. hoof growth is approx 1/4 inch a month (3 inches a year)

Question 2

why is detection and definitive diagnosis of lameness a challenge in cattle? (3)

Answer 2

1. stoic (prey) animals: disguise discomfort
2. lack of familiarity with subtle nonspecific signs means lameness usually progresses to untreatable by the time a vet is called
3. surface: beef on soft surfaces versus dair on hard surfaces

Question 3

what are 3 important components for identifying causes and managing lameness on a herd level?

Answer 3

1. proper diagnosis: abilities somewhat limited
2. record keeping: to be able to tell if progressing, genetic components to some lameness disorders, temporal aspect (cluster/outbreak?)
3. need to be able to answer:
   -which disorders are most prevalent?
   -at what rate are they occurring?

combine with production data to facilitate farm-level decision making:
-better management of individual cow: treat or cull
-

Question 4

what are 4 steps to diagnose and manage lameness?

Answer 4

1. ID lame cows and determine severity of insult
2. determine if foot is swollen (MOST lameness in cattle is in foot); infectious versus noninfectious
3. examine foot for lesions
4. apply appropriate diagnostics and treatment

Question 5

compare and contrast diagnosing and managing lameness in cattle versus equine

Answer 5

1. cattle lacks specificity relative to equine:
   -flexion and extension tests hard because cattle not handles as much
2. history, stance, stride, and examination critical to diagnosis for both cattle and equine

Question 6

describe assessment for lameness (5)

Answer 6

1. posture and gait abnormalities can be clues to origin of lameness: cattle naturally attempt to reduce weight bearing on affected foot
2. gait should be assessed on a dry, firm flooring surface
3. primary characteristics for assessment include (6):
   -walking speed
   -stride length and tracking
   -weight bearing
   -symmetry
   -posture of spine
   -head bob
4. use the locomotion scoring system (explained later)
5. evaluate the foot and distal limb for evidence of swelling; check the distance between dewclaws on each foot and compare to the sound foot (is swelling symmetric or asymmetric?)

Question 7

describe the locomotion scoring scale

Answer 7

1-5

1: normal, back flat, cow stands and walks with a level back and gait is normal

2: mildly lame, back is flat or arched, cow stands level backed, but develops an arched back to walk and gait is normal

3: moderately lame, back is arched, evident when standing and walking and gait is short strided

4: lame, back is arched; arch is always evident and gait is deliberate one step at a time; cow favors one or more legs/feet

5: severely lame, 3-legged, cow demonstrates an inability or extreme reluctance to bear weight on one or more limbs/feet

2-3 are subclinical, 4-5 are clinical

Question 8

describe the foot assessment for lameness (6)

Answer 8

1. pick up the foot
2. clean with soap and water
3. inspect for lesions, swellings, or evidence of foreign bodies
4. evaluate mobility of joints and heat over specific regions
5. use hoof testers in locations were lesions are common
6. trim hooves to reestablish normal proportions to claw capsule

Question 9

describe the biomechanics of weight bearing and how it relates to lameness (6)

Answer 9

1. a majority of lameness involves the lateral claw of the foot of a hind limb
2. rules of thumb:
   -in the hind limb: lateral claw bears majority of the weight
   -in the forelimb: medial claw bears majority of weight
3. the coxofemoral joint permits transfer of weight to the lateral claw
4. the increased blood flow from weight bearing leads to irritation of the corium of the lateral claw and accelerated growth of the hoof horn mostly at the heel
5. excessive weight and pressure on the heel can displace weight to the medial claw and cause the cow to develop a hocked gait
6. transfer of weight to the axial portion of the lateral claw can result in horn overgrowth in the interdigital space

Question 10

what is the purpose of functional and corrective hoof trimming?

Answer 10

1. overgrowth is a natural consequence of weight bearing (grows at 5-7mm/month)
2. this overgrowth is manifested at the toe, due to a harder horn, more rapid growth, and lower rate of wear
3. overgrowth is encountered clinically as lengthening and raising the toe with lowering the heel; more exaggerated in animals with laminitis or housed on hard flooring surfaces and accelerated patterns of growth

Question 11

when is functional and corrective hoof trimming performed? (3 scenarios)

Answer 11

large dairy operations:
1-2x per year (mid lactation and dry off)

as needed in beef cattle: when lame or obvious/severe overgrowth; more frequent in show animals

every 3-6 months in cattle with laminitis or other hoof growth abnormalities

Question 12

what are the 3 primary goals of functional and corrective hoof trimming?

Answer 12

1. restore appropriate weight bearing within each claw
2. correct overgrowth that leads to overburdening of specific claws
   -will not achieve perfect balance between claws, instead target reduction in local maximal pressures at weaker parts of the hoof
3. identify and correct claw lesions at an early age

Question 13

describe restraint for functional and corrective hoof trimming

Answer 13

1. facilities can be a limiting factor; DONT do in field unless cannot avoid
2. tilt table or hydraulic chute; or manual head catch + chute and create a pulley to lift foot
3. retrain most dangerous foot (to you, your height, etc.) first and release it last
4. can do recumbent trimming: sedation/anesthesia and cast with rope

Question 14

what are the 4 steps to hoof trimming?

Answer 14

1. reduce length of wall of non-weight bearing claw no less than 3 inches
   -pare weight bearing surface flat and maintain sole thickness of 5-7mm
   -preserve heel depth
2. trim weight bearing claw using previously trimmed claws as a guide
3. shape and slope the sole so that it slopes toward the center of the caws
   -reduces pressure over sole ulcer site
   -reduces accumulation of debris in interdigital space: prevention interdigital disease
4. balance the heels: all weight bearing surfaces should be flat across the toes, wall, and heels of both claws

Question 15

what are some extra considerations of hoof trimming? (3)

Answer 15

part of fixing a foot means trimming the foot!

1. pare away all loose hoof horn and hard ridges no matter how extensive
   -only healthy tissue should be left in place
   -consider resection of adjacent hoof wall when white line lesions are present
2. always stop trimming if hemorrhage is noted (unless paring away sole and can’t get necrotic tissue out any other way)
3. preserve as much of the weight bearing surface as possible

Question 16

what is functional hoof trimming used for?

Answer 16

1. sole ulcers
2. white line disease
3. interdigital fibromas: surgical correction

Question 17

why is functional and corrective hoof trimming underutilized in vet med?

Answer 17

1. reluctance to invest in hella expensive equipment
2. monotony with large groups of cattle
3. hard and dirty work
4. most conditions seen in dairy and beef cattle associated with hoof overgrowth, so routine trimming can reduce prevalence of issues and provide a return on investment

Question 18

describe interdigital fibroma removal (6)

Answer 18

1. clip and scrub area just proximal to interdigital space
2. regional anesthesia via Bier block (tourniquet placed proximal to dewclaws, 19g butterfly catheter into common digital vein 15-20 mL lidocaine)
3. sterile scrub interdigital space
4. incise border of fibromas and follow incision through interdigital space (be mindful of deeper structures)
5. place sterile 4x4 into interdigital space and bandage foot
6. wire claws together

Question 19

describe 3 changes in management that may be crucial for treatment and prevention of hoof pathology

Answer 19

1. diet: prevent subclinical and clinical laminitis
2. housing: hard flooring, organic debris accumulation
3. handling facilities: grating, impact when leaving chutes

Question 20

describe block application

Answer 20

put a wooden or rubber block (have two toes)

1. relieve weight bearing on affected claw
2. stay in place for 6-8 weeks (can work in just 2 weeks); should fall off on its own but remove if on longer than 8 weeks or if lameness worsens

Question 21

describe antimicrobial use for lameness

Answer 21

in cases of foot rot, digital dermatitis, septic arthritis

beware of extralabel use!!

consider withdrawal time

Question 22

describe use of anti-inflammatories or analgesia for lameness

Answer 22

good for any condition; consider animal welfare, performance and recovery, and withdrawal time