Less common causes of lameness

Question 1

Less common causes of lameness originating in the foot

Answer 1

• foreign bodies
• heel horn erosion (slurry heel)
• fissures
• fracture of P3
• interdigital hyperplasia

Question 2

Foreign bodies

Answer 2

• quite common
• sharp FB penetrate through the sole
• e.g. nails, sharp stones, blackthorns, shards of glass or metal
• painful, can result in abscess (from tracking infection)

Question 3

FB clinical presentation

Answer 3

• sudden onset severe lameness
• typically only 1 limb affected

Question 4

FB diagnosis

Answer 4

• FB visible if still in situ
• black tracks through sole leading to a sub-sole abscess are also diagnostic

Question 5

FB tx

Answer 5

• remove FB if still present
• decried sole to open up and drain abscess (using hoof knife)
• apply block to unaffected claw
• pain relief +/- AB as needed

Question 6

FB prognosis

Answer 6

• good in straightforward cases
• if very deep, prognosis is poorer

Question 7

FB prevention

Answer 7

• keep environment as free from FB as possible
• always pick up dropped needles or advise farmer if cannot find them

Question 8

Heel horn erosion (‘slurry heel’)

Answer 8

• common
• prolonged standing in wet slurry
  – erodes soft horn of heel
  – results in pits and fissures in heel horn
• in severe cases fissures form a V shape

Question 9

Heel horn erosion clinical presentation & diagnosis

Answer 9

• classic presentation – is diagnostic

Question 10

Heel horn erosion tx

Answer 10

• regular foot bathing to harden heel horn
• remove loose and damaged heel horn
• spare healthy heel horn when trimming feet

Question 11

Heel horn erosion prognosis

Answer 11

• good in earlier stages
• poorer in later stages when heel significantly eroded as changes in hoof angle predisposes to other claw lesions

Question 12

Heel horn erosion prevention

Answer 12

• improved environmental cleanliness

Question 13

Fissures

Answer 13

• not very common
• poorly understood
• vertical, horizontal and axial wall fissures
• don’t usually cause lameness unless complications e.g. secondary infection present -> this is rare
• if abscess present or corium exposed deriding of the edges of the fissure can be performed and apply a block to reduce shearing forces, otherwise no tx is needed

Question 14

Vertical fissure

Answer 14

• ‘sandcrack’
• beef cattle more common than dairy cattle
• hot, dry, sandy environment implicated
• may occur secondary to damage to periople

Question 15

Horizontal fissure

Answer 15

• ‘hardship line’
• occur when production of wall horn is interrupted
• usually due to severe illness or metabolic disturbance
• often all 8 claws affected

Question 16

Axial wall fissures

Answer 16

• aetiology unclear
• extend longitudinally from sole to coronary band on axial wall of hoof

Question 17

Fracture of P3

Answer 17

• uncommon
• sudden onset, severe lameness
• can be difficult to diagnose clinically -> often presumptive diagnosis made based on clinical signs
• x-ray needed for definitive diagnosis
• US has been described

Question 18

Fracture P3 clinical signs

Answer 18

• sudden onset, NWB lameness
• increased digital pulses
• foot hot to touch, and coronary band is reddened
• flexion of extension digits = painful
• twisting of affected claw = painful
• percussion of affected claw/application of hoof testers = painful
• crossed-leg stance if medial front claw affected -> cow tried to put weight more onto lateral claws

Question 19

Fractured P3 tx and prognosis

Answer 19

• block unaffected claw for 6-8w
• healthy claw will stabilise fractured claw
• good nursing (soft bed)
• pain relief in initial stages
• prognosis is good in uncomplicated cases
• infection is associated with poorer prognosis

Question 20

Interdigital hyperplasia

Answer 20

= corns, tyloma, fibroma, granuloma, growth
- excessive growth of tissue in interdigital space
- not well understood but probably multifactorial
- chronic irritation of interdigital space is primary factor
– dairy: often related to other infectious hoof lesions (e.g. digital dermatitis)
– beef: underlying causes are less clear

Question 21

Interdigital hyperplasia clinical presentation and diagnosis

Answer 21

• classic presentation (often diagnostic)
• often doesn’t cause lameness and are incidental findings when foot is trimmed
• check rest of foot to rule out other (concurrent) causes of lameness associated with interdigital hyperplasia is uncommon

Question 22

Interdigital hyperplasia tx

Answer 22

• if underlying infectious lesion present, treatment of this may lead to resolution of hyperplasia
• small lesions don’t need treating
• mild dishing of hoof may relieve pinching of small to medium lesions
• large lesions unresponsive to other treatment may need surgical resection -> take care to dissect out fat pad and to not cause damage to interdigital ligaments

Question 23

Interdigital hyperplasia prognosis

Answer 23

• good

Question 24

Interdigital hyperplasia prevention

Answer 24

• take measures to reduce infectious causes of lameness

Question 25

Less common causes of lameness associated with the rest of the limb

Answer 25

• blackleg (clostridial myositis)
• osteochondrosis dissecans (OCD)
• fractures
• MSK injuries

Question 26

Blackleg (clostridial myositis) aetiology

Answer 26

• bacterial cause = clostridium chauvoei
• soil-borne infection -> bacteria enters through lesions of skin or mucosa
• calving/lambing injuries and fresh navel are risk factors
• often no known hx of trauma in older cattle

Question 27

Blackleg (clostridial myositis) presentation

Answer 27

• causes severe necrotising myositis -> severe lameness and upper limb muscle swelling
• commonly seen in young growing cattle 6m-2y
• often die soon after CS appear (12-36h)
• but, most common presentation is sudden death so don’t always see lameness

Question 28

Blackleg (clostridial myositis) PM findings

Answer 28

• dx usually achieved through PME
• important ddx is anthrax
• affected muscles are dry and dark on cut surface

Question 29

Blackleg (clostridial myositis) tx and prevention

Answer 29

• tx of live animals = high dose penicillin (double dose q12-24h)
• prevention is better due to high mortality rate
  – vaccination: monovalent and multi-valent available
  – initial course at 3-6m old followed by annual boosters
• move cattle off affected pasture
• prophylactic penicillin for up 14d is also suggested to prevent losses in outbreaks (but the practicalities and cost of treating every animal needs to be carefully considered)

Question 30

OCD pathophysiology and signalment

Answer 30

• focal defect in articular cartilage resulting from failure of blood supply development during ossification -> focal ischaemic necrosis
• typically young, fast growing animals
  –?genetics
  –?nutritional deficiency

Question 31

OCD presentation

Answer 31

• chronic lameness -> stifles and hocks most commonly affected
  – stiffness, reluctance to stand/move +/- joint swelling
  – lesions usually bilateral but lameness might be 1 leg only
• on PME cartilage deficits are evident

Question 32

Fractures of older and adult cattle

Answer 32

• limb fractures are most common
  – metacarpus/metatarsus ~50%
  – tibia ~12%
  – radius, ulna and humerus combined <12%
• femoral and pelvic fractures and fractures of the axial skeleton can occur but are rare

Question 33

Bovine limb fractures - general principles

Answer 33

• cattle are very good orthopaedic pts because they
  – are happy to spend a lot of time lying down
  – are tolerant of fixation devices
  – have excellent bone healing capacity
• the size and weight of cattle can make fixation difficult
  – sometimes you need to be creative to make a device of appropriate strength and size to be effective
• closed bone fractures are very amenable to external coaptation and have a reasonable prognosis
• open fractures have a poorer and euthanasia should be considered
• increasing body weight makes external coaptation less successful
• more advanced fixation techniques are possible for larger animals but aren’t D1C

Question 34

Pelvic fractures

Answer 34

• uncommon
• tuber coxae fractures can be seen if cows bump into walls/fences/gates when rushing through narrow entrances or are pushed into hard surfaces by other cows
  – other fractures of the pelvis are very rare
• NWB so responds well to conservative tx (rest, analgesia, good nursing)
• occasionally sequestrum forms -> may need surgical removal
• prognosis generally excellent
  – often these are noticed incidentally a long time after the event

Question 35

Tuber coxae fractures presentation

Answer 35

• one tuber coxae present
• other tuber coxae absent as it has fractured
• mild lameness might be present when this is in the acute stages but often these fractures go unnoticed because CS are so mild
• clinical presentation is diagnostic
• if a sequestrum has formed there may be an associated draining tract

Question 36

MSK injuries examples

Answer 36

• hip luxation
• gastrocnemius tendon rupture
• stifle injuries
• hock bursitis

Question 37

Hip luxation

Answer 37

• rarely seen -> most commonly after calving
• ~80% have craniodorsal luxation of the femoral head
• diagnosis is based on CE and palpation
  – these can be very difficult to differentiate from fractures of the femoral head
• most common direction of luxation is craniodorsal so femoral head will be palpable above and in front of normal hip position

Question 38

Management of hip luxation

Answer 38

• hip can often be manually replaced
  – sedate or GA the cow
  – acute cases have better success
• in longer standing cases reduction is difficult as muscles become firm around the dislocated hip
  – euthanasia may be warranted
• prognosis is reasonably in uncomplicated cases
  – better in cases treated quickly
  – recurrence of luxation = poorer prognosis

Question 39

Gastrocnemius tendon rupture

Answer 39

• pathognomonic presentation
• sudden onset
  – tendon typically ruptures when cows struggling to rise
  – typically associated with poor flooring (slipper) or other conditions affecting ability to rise (e.g. hypocalcaemia)
• tx involves splinting or casting affected limbs into (functional) extension for long enough to allow tendon healing
  – in larger animals this is frequently unrewarding -> consider PTS
  – can be effective in calves and small ruminants

Question 40

Stifle injuries

Answer 40

• moderately common
• typically present with non-specific hindlimb lameness
  – joint effusion, crepitus, pain are common CS
  – may be able to elicit cranial drawer if cruciate ligament ruptured
• typically conservative therapy is warranted
  – analgesia
  – soft bed
  – rest
  – good nursing

Question 41

Hock bursitis

Answer 41

• commonly seen in housed cattle
• an indicator of cow comfort -> an indicator of hock abrasions and trauma
  – sporadic cases often seen but if many cases seen, consider investigation into cow comfort
• usually don’t cause lameness
  – unless secondary complications (e.g. infection) present
• usually no tx needed -> can move to straw bed or outside if necessary
• don’t incise and attempt to drain these
  – unnecessary and may introduce infection
  – can be slow to heal due to the inciting cause being chronic trauma/abrasion of the hock

Question 42

Hock scoring - score O

Answer 42

• no, or mild (<2cm) hair loss
• generally considered normal

Question 43

Hock scoring - score 1

Answer 43

• 1 or more patches of hair loss measuring >2cm diameter

Question 44

Hock scoring - score 2

Answer 44

• swelling (bursitis) present
• <5% cows in the herd should present like this
• there may also be skin injuries or scabs present