22.5.2: Less common causes of lameness Flashcards
Sole haemorrhage/bruising
Foreign body penetration
Heel horn erosion (Slurry heel)
Vertical fissure (a.k.a. sand crack) with granuloma above
(Mild) Horizontal fissures (Hardship lines)
More severe horizontal fissures (hardship lines) resulting in the formation of thimbles
Comment on this cow’s stance
Classic cross-legged stance adopted by a cow with a fractured phalanx (medial claw, right foreleg)
Interdigital skin hyperplasia (a.k.a. interdigital corns/growth/fibromas/granulomas)
Describe the aetiology of slurry heel
- The result of standing in wet corrosive slurry during the winter housing period leads to the soft horn of the heel becoming eroded
- Pits and fissures form in the heel
- If severe, or left untreated, the heel eventually disappears completely
Treatment of slurry heel
- Regular formalin foot baths through the winter will harden the feet and limit the effects of heel erosion
- Gently trim away loose and fissured horn to remove pocket but spare healthy heel as excessive trimming will exacerbate the problem
- Corrective trimming aims to increase the angle of the front wall to the ground to reduce the pressure on the ulcer site
Prognosis for slurry heel
- Good if treated before the disease has completely destroyed the heel
- If this has been allowed to happen, the foot rotates backwards
- The front wall of the hoof meets the ground at a shallower angle -> leads to overgrowth of the hoof at the toe
- Meanwhile pressure exerted by pedal bone pinches the corium and can lead to development of sole haemorrhage and eventually sole ulcers
Prevention of slurry heel
- Improve underfoot conditions during the winter period will decrease the severity of the condition
- Certain amount of heel erosion is almost inevitable in housed cattle
- Routine formalin foot baths will often limit the severity of disease
Aetiology of vertical fissures (sand cracks)
- Damage to the periople (produces waxy layer that prevents horn drying out) or the underlying corium (produces wall of horn) causes vertical cracks
- Digital damage lesions/trauma/hot dry sandy conditions can cause this
Treatment of vertical fissures (sand cracks)
- Open the crack up and exposed underlying abscesses to allow them to drain
- If the crack is opened and there is movement between the two wall sections, granulation tissue can develop and protrude through -> in these cases, resect granulation tissue and apply block to sound claw to limit sheering forces
Prognosis for vertical fissures
- Generally good although some can be quite difficult to treat and require multiple trims before the wall returns to normal
- If periople has been permanently damaged leading to long-term continual production of defective wall, prognosis is poor
Aetiology of horizontal fissures (hardship lines)
- The production of wall horn is interrupted as it is being produced at the coronary band
- Any severe toxic condition (mastitis, metritis, acute acidosis) can result in temporary but complete absence of horn production
- When horn production restarts, there will be a complete circumferential fissure often round all 8 claws
Clinical signs of horizontal fissures (hardship lines)
- Often asymptomatic unless the fissure and underlying laminae become infected or the pinching forces result in the production of a granuloma
- May show clinical signs when fissure has grown down the wall and led to the formation of fissures -> lameness, infection, granulomas are seen
Treatment of horizontal fissures (hardship lines)
- If infection has been established, crack should be opened and underlying abscesses allowed to drain
- Any granulation tissue should be resected
- Often difficult/pointless to block the other claw as very often all claws are affected
Prognosis for horizontal fissures (hardship lines)
- Prognosis varies according to disease severity
- Sometimes thimbles grow out and are shed asymptomatically
- If all claws are seriously affected, it may be necessary to cull the affected animal
True/false: if disruption of horn production is not complete, thinning of the wall occurs. These thinner edges develop into ridges (hardship lines) as the wall grows.
True
Aetiology of distal phalanx fractures
- Medial claw of front feet - trauma during bulling (slipping off cows whilst mounting)
- Hind feet - slipping in parlour
- Herd “outbreaks” have been associated with fluoride poisoning
Clinical signs of distal phalanx fractures
- Acute onset lameness with no other obvious clinical signs
- If the medial claw of the front feet is affected, animals will often stand “cross-legged” so as to take the weight on the unaffected lateral claw
Treatment of distal phalanx fractures
- Distal phalanx is splinted well by the hoof capsule
- Apply a block to the unaffected claw
- (I can’t help but think some NSAIDs might be in order too?!)
Prognosis for distal phalanx fractures
- Good providing no other complicating factors e.g. fluoride poisoning
Aetiology of interdigital skin hyperplasia
- Chronic irritation of the interdigital area e.g. chronic infection, impaction of small stones/dirt
- Foul in the foot may predispose to the condition later in life
- Hereditary component has been postulated but remains unproven
Clinical signs of interdigital skin hyperplasia
- Often asymptomatic; incidental finding during foot trimming
- Causes lameness is overgrowth of skin becomes infected (foul, DD) or becomes so large that it is pinched between the claws during locomotion
Treatment of interdigital skin hyperplasia
- If hyperplastic area is infected -> treat infection, this will often resolve the lameness
- In cases where pinching is mild, “dishing” out the horn from the interdigital area will often alleviate clinical signs
- In severe cases/where corrective trimming, surgically remove the hyperplastic skin under local or intravenous regional anaesthesia
Prognosis for interdigital skin hyperplasia
Good
Prevention of interdigital skin hyperplasia
- Ensure underfoot conditions are optimal during winter housing period
Aetiology of suprascapular paralysis
- C6 and C7 outflow provides motor innervation to supraspinatus and infraspinatus muscles
- Usually damaged by trama to prescapular or scapular area
Clinical signs of suprascapular paralysis
- Limb can be advanced, but abducts when weight bearing
- Stride may be shortened
- Atrophy of supraspinatus and infraspinatus muscles can be partial or almost complete
Radial paralysis in left foreleg
Radial paralysis of left forelimb
Radial nerve paralysis
In more extreme presentations, where the dorsum of the pastern is in contact with the ground, then paralysis of the whole brachial plexus should be considered.
Radial nerve paralysis
Aetiology of radial paralysis
- C7, C8 ?? and T1 outflow provide motor innervation of carpus and digit extensors and sensation to lateral side of limb
- Excessive traction on limb (e.g. during calving), trauma to scapulohumeral area, and recumbency can damage the nerve
Clinical signs of radial paralysis
- Damage to the nerve proximally leads to the wall being held in flexion with the elbow dropped
- The cranial wall of the hoof “scuffs” the floor during locomotion
- If the nerve is damaged distally, innervation of the elbow is often normal but the carpus and fetlock are held in flexion
Aetiology of brachial plexus paralysis
- C5 to T2 outflow make up the principal nerves innervating the forelimb (radial, median and ulnar)
- Excessive traction on the limb (e.g. during calving), traumatic abduction and prolonged lateral recumbency can all damage the brachial plexus
