Less common causes of lameness Flashcards
1
Q
Less common causes of lameness originating in the foot
A
- foreign bodies
- heel horn erosion (slurry heel)
- fissures
- fracture of P3
- interdigital hyperplasia
2
Q
Foreign bodies
A
- 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)
3
Q
FB clinical presentation
A
- sudden onset severe lameness
- typically only 1 limb affected
4
Q
FB diagnosis
A
- FB visible if still in situ
- black tracks through sole leading to a sub-sole abscess are also diagnostic
5
Q
FB tx
A
- 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
6
Q
FB prognosis
A
- good in straightforward cases
- if very deep, prognosis is poorer
7
Q
FB prevention
A
- keep environment as free from FB as possible
- always pick up dropped needles or advise farmer if cannot find them
8
Q
Heel horn erosion (‘slurry heel’)
A
- 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
9
Q
Heel horn erosion clinical presentation & diagnosis
A
- classic presentation – is diagnostic
10
Q
Heel horn erosion tx
A
- regular foot bathing to harden heel horn
- remove loose and damaged heel horn
- spare healthy heel horn when trimming feet
11
Q
Heel horn erosion prognosis
A
- good in earlier stages
- poorer in later stages when heel significantly eroded as changes in hoof angle predisposes to other claw lesions
12
Q
Heel horn erosion prevention
A
- improved environmental cleanliness
13
Q
Fissures
A
- 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
14
Q
Vertical fissure
A
- ‘sandcrack’
- beef cattle more common than dairy cattle
- hot, dry, sandy environment implicated
- may occur secondary to damage to periople
15
Q
Horizontal fissure
A
- ‘hardship line’
- occur when production of wall horn is interrupted
- usually due to severe illness or metabolic disturbance
- often all 8 claws affected
16
Q
Axial wall fissures
A
- aetiology unclear
- extend longitudinally from sole to coronary band on axial wall of hoof
17
Q
Fracture of P3
A
- 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
18
Q
Fracture P3 clinical signs
A
- 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
19
Q
Fractured P3 tx and prognosis
A
- 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
20
Q
Interdigital hyperplasia
A
= 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
21
Q
Interdigital hyperplasia clinical presentation and diagnosis
A
- 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
22
Q
Interdigital hyperplasia tx
A
- 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
23
Q
Interdigital hyperplasia prognosis
A
- good
24
Q
Interdigital hyperplasia prevention
A
- take measures to reduce infectious causes of lameness
25
Less common causes of lameness associated with the rest of the limb
- blackleg (clostridial myositis)
- osteochondrosis dissecans (OCD)
- fractures
- MSK injuries
26
Blackleg (clostridial myositis) aetiology
- 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
27
Blackleg (clostridial myositis) presentation
- 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
28
Blackleg (clostridial myositis) PM findings
- dx usually achieved through PME
- important ddx is anthrax
- affected muscles are dry and dark on cut surface
29
Blackleg (clostridial myositis) tx and prevention
- 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)
30
OCD pathophysiology and signalment
- 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
31
OCD presentation
- 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
32
Fractures of older and adult cattle
- 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
33
Bovine limb fractures - general principles
- 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
34
Pelvic fractures
- 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
35
Tuber coxae fractures presentation
- 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
36
MSK injuries examples
- hip luxation
- gastrocnemius tendon rupture
- stifle injuries
- hock bursitis
37
Hip luxation
- 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
38
Management of hip luxation
- 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
39
Gastrocnemius tendon rupture
- 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
40
Stifle injuries
- 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
41
Hock bursitis
- 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
42
Hock scoring - score O
- no, or mild (<2cm) hair loss
- generally considered normal
43
Hock scoring - score 1
- 1 or more patches of hair loss measuring >2cm diameter
44
Hock scoring - score 2
- swelling (bursitis) present
- <5% cows in the herd should present like this
- there may also be skin injuries or scabs present
