Cattle Foot Lameness Flashcards
Three most important causes of lameness in dairy cattle
Sole ulceration
White line disease
Digital dermatitis
Where does most bovine lameness occur?
Lateral claw of hind feet
What structure can protrude through horn in sole ulcers?
Corium (very sensitive)
What is white line disease?
Bruising/inflammation/infection/separation of white line
Factors causing excess pressure on dermis (3)
Calving effect
Environmental factors (including hoof overgrowth)
Changes to normal structure of the hoof
What is the calving effect?
Relaxin causes tendons and ligaments to relax, including suspensory apparatus leading to rotation of the pedal bone
True or false: the fat pad returns to its original quality after damage
False (it becomes scarred and less springy)
What is the problem with prolonged standing time on concrete/hard surfaces?
Flattens and increases the width of the lateral claw which transfers load to central part of sole, increasing pressure on the dermis
True or false: weight loss affects the fat pads
True (especially in lactation)
Which structure is affected by bony change after lameness of the foot?
P3 (increases likelihood of future lameness)
Mild sole haemorrhage/ulceration
Incorporation of blood into horn as sole is produced
Moderate sole haemorrhage/ulceration
Partial/intermittent interruption of horn production at sole ulcer site
Severe sole haemorrhage/ulceration
Horn production completely arrested at sole ulcer site for a prolonged period
Clinical signs of sole ulceration/haemorrhage
Slight to severe lameness
Often both hind feet (one worse)
Predominantly lateral claw of hind feet and medial claw of fore feet
Haemorrhagic discolouration progressing to complete cessation of horn production at sole ulcer site
Possible secondary infection
Deep digital sepsis can occur
Diagnosis of sole ulceration/haemorrhage
Pathognomic once inspected and trimmed
Can use hoof testers if no obvious lameness
Treatment of sole ulcer/haemorrhage
Corrective trimming
‘Dish’ site
Remove underrun horn/granuloma
Apply foot block to sound claw
NSAIDs
Parenteral antibiotics if signs of infecton
Place on deep straw bed if severe
Prognosis for sole ulcers is generally good, but what are the poor prognostic indicators?
Multiple claws affected
Severe lesion
Deep digital sepsis
Clinical signs of white line disease
Moderate to severe lameness
Lateral claw more commonly affected
Swelling at coronary band
+/- large abscess
Leg abducted to bear weight on medial claw
Does white line disease occur at different frequencies in different parts of the foot?
Yes
Diagnosis of white line disease
Pain if “tweak” claw
White line impaction and abscess if trimmed and explored
Small pin prick size holes to large areas of impaction on the white line (always black)
Where can white line disease abscesses erupt from?
Coronary band
Treatment for white line disease
Trim and balance both claws
Explore impacted white line, drain abscess (if present), remove under run sole (at least enough to prevent re-impaction)
If tracked up wall, remove entire section of wall
Antibiotic dressing?
Foot block other claw
NSAIDs
Parenteral antibiotics may be necessary if necrotic corium is found
How long can antibiotic dressing remain on a claw?
48 hours maximum
Prognosis for white line disease
Good
(Tracks up wall more difficult to treat, occasional deep digital sepsis)
True or false: digital dermatitis is endemic in the UK
True (most farms have had a case, those that haven’t need good biosecurity and should check feet of cows before buying in)
Aetiology of digital dermatitis
Multifactorial infectious bacterial disease
(3 groups of spirochetes plus other opportunistic/secondary invaders)
Spirochete groups involved in digital dermatitis
Group 1: Treponema medium/vincentii
Group 2: Treponema phagedenis
Group 3: Treponema pedis
True or false: many ruminant species affected by digital dermatitis
True (cattle, sheep, elk, goats, also pigs)
What is the main reservoir of digital dermatitis?
Lesions on infected animals (may be only reservoir)
Which common foot lameness has genetic susceptibility?
Digital dermatitis (can breed for resistance)
Clinical signs of digital dermatitis
Mild lameness (may progress to severe)
Interdigital area between heel bulbs
Small (1-4cm), circular, moist, brown/grey, exudative area of epidermal liquefaction and matting of surrounding hair
What occurs if digital dermatitis is untreated?
‘Papilliform’/’hairy warts’: long, thick strands of keratin protruding from underlying granulation bed
What classification system is widely used for digital dermatitis?
‘M’ classification system by Dopfer et al
What is the ‘M’ classification?
M0
What is the ‘M’ classification?
M1
What is the ‘M’ classification?
M2
What is the ‘M’ classification?
M3
What is the ‘M’ classification?
M4
Why is M4 most likely reservoir of infection?
Cows with M4 may not be lame
What is the ‘M’ classification?
M4.1
Is progression of digital dermatitis from M0/1 to M4.1 linear?
No
Diagnosis of digital dermatitis
Clean and examine, lesions are pathognomic
Treatment of digital dermatitis in the individual
Clean (remove matted hair/scab)
Dry and apply topical antibiotic (oxytetracycline spray) or bandage with antibacterial products
Should herd wide antibiotic footbaths be used to control digital dermatitis?
No
(Alternative: targeted topical treatment following identification of lesions in milking parlour)
Prognosis for digital dermatitis
Good, but with concerns that newer presentations are harder to treat
(Except lesions on front of foot which damage periople impairing production of wall –> under running)
What disease is colloquially referred to as ‘foul’/’claw ill’/’lewer’?
Interdigital necrobacillosis
Aetiology of interdigital necrobacillosis
Damage to skin (FBs, course straw etc.)
Introduction of Fusobacterium necrophorum (and secondaries e.g. A. pyogenes/Streptococcus spp.)
Acute necrotising inflammation of intedigital skin
Clinical signs of interdigital necrobacillosis
Sudden onset moderate to severe lameness
Inflammation of soft tissues around coronary band/between digits
‘Split’ in interdigital space which discharges pus/necrotic tissue
Characteristic foul smell
Anorexia/milk drop/weight loss/pyrexia?
Diagnosis of interdigital necrobacillosis
Pathognomic
Treatment of interdigital necrobacillosis
Check for FBs
Wash and flush with clean water
Debride necrotic tissue
Topical antibiotics
Parenteral antibiotics 3-5 days (oxytetracycline)
Prognosis for interdigital necrobacillosis
Good if treated early
Can lead to deep digital sepsis in aggressive cases/if left untreated
What is ‘super foul’?
More aggressive and severe interdigital necrobacillosis which quickly invades deep structures of foot
Treatment of ‘super foul’
Early and aggressive therapy
Clean, debride and flush (IVRA?)
Pack with antibiotics and bandage
Systemic antibiotics until signs resolve
What causes heel horn erosion/’slurry heel’?
Standing in wet corrosive slurry during winter housing causes erosion of soft horn of heel –> pits and fissures in heel
What can occur if slurry heel is left untreated/become severe?
Heel disappears completely
What condition is this?
Heel horn erosion/slurry heel
How is slurry heel diagnosed?
Pathognomic clinical signs
Treatment for slurry heel
Regular formalin foot bathing
Trim away loose horn, spare healthy heel
Corrective trimming
Prognosis for slurry heel
Good if treated before heel is destroyed
If heel is destroyed foot rotates backwards and there is overgrowth/sole ulceration
Prevention of slurry heel
Improve underfoot conditions
Routine bathing in formalin footbaths
What condition leads to this presentation?
Verticle fissures/sand cracks (damage to periople, otherwise asymptomatic unless infected)
Treatment and prognosis of sand cracks
Open crack and allow underlying abscess to drain if present
Generally good prognosis unless periople permanently damaged
What can appear if horn production is interrupted (often with severe toxic condition e.g. metritis, mastitis, acute acidosis)?
Hardship lines/horizontal fissures
When are clinical signs seen with hardship lines?
‘Thimbles’ (movement results in lameness, infection and granulomas)
Treatment of hardship lines
Open up cracks if there is infection and resect granulation tissue
Prognosis of hardship lines
Varies with severity, if all claws seriously affected by thimbles may need to cull animal
What condition of the foot might you suspect with rapid acute onset lameness and no other clinical signs?
Fracture of distal phalanx
Causes of fracture of distal phalanx
Trauma during bulling (medial claw of front feet)
Hind feet slipping off steps
Herd fluoride poisoning
Diagnosis of distal phalanx fracture
Radiograph
Treatment of distal phalanx fracture
Application of block to unaffected claw
Prognosis for distal phalanx fracture
Good unless there is a complicating factor e.g. fluoride poisoning
What can occur with chronic irritation of the interdigital skin due to infection or impaction of grit?
Interdigital skin hyperplasia (interdigital corn/growth/fibroma/granuloma)
What condition may occur later in life to a cow that has suffered from fowl?
Interdigital skin hyperplasia
Clinical signs of interdigital skin hyperplasia
Often asymptomatic
Lameness if infected or so large it is being pinched
Diagnosis of interdigital skin hyperplasia
Pathognomic but if cow is lame look for other causes of lameness
Treatment of interdigital skin hyperplasia
Treating infection will resolve lameness
Mild pinching: dish out horn from area
Severe pinching: surgical removal (local or IVRA)
Prevention of interdigital skin hyperplasia
Optimum underfoot conditions in winter housing period
