Farm lameness etc Flashcards
Bovine Digital dermatitis: Aetiology? Clinical signs? Stages?
MOST IMPORTANT INFECTIOUS BOVINE FOOT DISEASE
Treponema pedis, medium-like, phagedenis-like = most important species (polymicrobial symbiotic pathogenesis suggested as often 5 different treponema species co-infect)
Painful reddened area usually just above interdigital cleft between heel bulbs
May be erected hair around the lesion
M1: early lesions <2cm
M2: classical ulcer, acute, active, >2cm, lame
M3: healing stage with scab formation after topical treatment
M4: chronic stage, dyskeratosis and proliferation, often not painful
M4.1: Chronic with subacute components too (active)
Treatment and control for bovine digital dermatitis?
Get in crush
Clean and dry lesion well gently
Apply topical antibiotic treatment - oxytet spray
Repeat daily for at least 3 days
Other products e.g. salicylic acid?
Formalin/copper sulphate foot baths
Antibiotic footbaths? - shouldn’t do as resistance problems, off label use (7 milk day withdrawal), unresponsible use for whole herd
Control:
- host immunity is not protective
- regular foot bathing
- improve farm hygiene
- appropriate foot trimming with disinfected equipment
- herd biosecurity
(Bovine) Foul in the foot: Other names? Aetiology? Clinical signs?
= Interdigital phlegmon/interdigital necrobacillosis Fusobacterium necrophorum Poss also Bacteroides melaninogenicous Signs: - Acute onset! - Swelling of interdigital space - Characteristic odour - Usually very painful - Severe lameness - Fever, anorexia - Reduced milk yield
Treatment for (Bovine) Foul in the foot? Infection reservoirs? Control?
ASAP!!
Get in crush
Check for foreign body
Clean lesion really well
Remove necrotic tissue
SYSTEMIC antibiotics (tylosin, lincomycin, oxytetracycine, ceftiofur?) - most broad spectrum will work
Infection reservoir = environment and manure
Footbathing with disinfectants to control
(Bovine) Interdigital dermatitis: Aetiology? Clinical signs? Treatment?
Dichelobacter nodosus
Milder infection of interdigital skin than foul in the foot (not very painful, no foul smell)
Can spread across the heels (heel horn erosion) = slurry heel
Foot trimming and poss topical antibiotic treatment
What are (bovine) sole haemorrhages/bruising, sole ulcers and white line lesions called together? What are they traditionally associated with?
Claw Horn Disruption Lesions (CHDL) - trauma/contusions within claw horn capsule
Traditionally associated with subclinical laminitis/SARA (weakening of suspensory apparatus)
(Bovine) sole haemorrhages/bruising: What is it? Cause? Which claws usually affected
= Contusion of the corium
Usually from pressure from pedal bone
Sometimes external pressure (e.g. stones), especially when soles are thin
Usually lateral claw due to weight distribution
Early stage of sole ulcer
Can cause double sole formation
Sole ulcers in cows: What are they? Cause? Result?
More severe manifestation of the same disorder as sole haemorrhages/bruising
Ie mainly caused by trauma/contusions of the corium from the pedal bone
Disrupted sole horn production and exposure of the corium
Treatment for sole haemorrhages and sole ulcers in cows?
Get in crush now, better if early
Functional trimming (Dutch method, 5 steps)
Block unaffected claw (don’t if any lesions even if mild)
NSAIDs - painful!
White line lesions in cows: Cause? What happens? Treatment?
Association with shearing/sideways forces on the feet
Separation, stones/manure
Claw overload, contusions of corium may also be associated
Abscess formation
Get in crush now
Functional trimming (Dutch method, 5 steps_
Remove detached horn
Block unaffected claw
NSAIDs?
Acute laminitis in cows: Cause?
Rare
Associated with grain overload
Weakening of suspensory apparatus/poor horn quality
Association with SARA? Role of systemic inflammation/hormones/hyperinsulinaemia?Endotoxins, increased activity go Matrix Metalloproteinases (MMPs)
Interdigital hyperplasia in cows: Cause? Treatment?
Poss due to chronic skin irritation (DD, IDD)
Hereditary factor?
Surgical removal under regional anaesthesia
Toe ulcers/necrosis in cows: Cause? Treatment?
Associated with overwear or overtiming of toe sole
Can get infected
Non healing toe necrosis associated with DD
Trim/block unaffected claw
Partial or full digital amputation
Vertical wall crack in cows: Clinical signs? Treatment?
Not always painful Exposed corium, granulation tissue Trimming Block unaffected claw? Stabilise hoof wall?
Deep digital sepsis in cows: Cause? Treatment?
Untreated foul in the foot, complicated sole ulcers, untreated white line abscesses, puncture wounds
Extremely painful
Amputation? Euthanasia? Arthrodesis?
Retroarticular abscess in cows: What is it? Clinical signs? Treatment?
Abscess above heel bulb
One claw, extensive painful swelling of the heel region of a single digit
Surgery
Digit amputation
Corkscrew claw in cows: What it is?
Dorsal edge of claw wall deviates from a straight line
Hereditary?
How to differentiate between upper limb lameness and foot lameness when walking in cows?
Upper limb - reduced swinging phase/forward stride of affected leg, or shortened stride of sound leg
Foot - normal swinging phase, lame when foot placed
How to identify which leg is lame in upper limb lameness in cows?
Head position at point of weight bearing:
- head up if front leg
- head down if back leg
Level of accessory digits when stood still
- if unequal then the one higher is the leg with the problem
Swing phase length when walking
Diagnostic methods for identifying the cause of upper limb lameness in cows?
Palpation and auscultation of joints - crepitus when taking step
Rectal
Flexion tests - start with distal joints moving up, holding up for 1+ mins, not as controlled as horses
Muscle symmetry - atrophy (disuse, neurological), swelling (haematoma, inflammation, effusion)
Check for wounds/pus, esp areas that look dirty
Ultrasonography - look for joint effusions, pelvic fractures (disruption of continuity of bright white line)
Radiography - bone integrity and position, joint effusions and degenerative changes, ST swelling, tissue integrity
MRI
Scintigraphy
Thermography
Nerve blocks - ring block above fetlock and move up
Contracted tendons in neonatal calf: Presentation? Cause? Treatment? What else to check for?
Usually only front legs
Usually only fetlock
Sometimes also carpus
Flexed position, can’t bear weight
Unknown cause - poss due to position in utero
Use splint to force into straight position with generous padding
If can’t manually force into straight position, can do tendonectomy - skin incision on ventral aspect, cut superficial flexor tendon and deep and suspensory if needed, then splint for couple of weeks
Check for FPT as hasn’t been able to get up and suckle - give colostrum
Check for other congenital problems
Ddx for neonatal calf unable to weight on front legs, which had assisted delivery?
Contracted tendons
Fractures from calving ropes/traction
Calf with carpal flexion: Cause to consider? Treatment?
Schmallenberg
Splint and physio
Gastrocnemius rupture in cows: Causes? Presentation? Ddx for same presentation? Treatment?
Causes:
- rotational force: wooden slatted floor (foot stuck between 2 and rotated as trying to free it)
- sudden weight
- trauma
- weakening
- hypophosphataemia? - high cereal rations, weakens tendons, bilateral, 1yr old beef
- compartment syndrome: downer cow or severe haematoma -> internal pressure necrosis predisposes
Presentation:
- upper leg straight, hock lower, more acute hock angle (flexed)
Ddx: tibial nerve paralysis (differentiating by testing skin sensation over plantar metacarpal area, mainly from spinal paralysis, cull)
Treatment: box rest in young calf, more difficult in older animals with bilateral problem
Flexor tendon injury in cows: Cause? Treatment?
Trauma most common with one wound and contamination
Spontaneous/infectious less common
Treat wound - intra-osseous AB?, debride/flush if can do clean
Infection must be controlled before consider cast
Tenorrhaphy and cast
Cast alone
Confinement +/- block
Can use ultrasound to see how bad effect on tendon is - treatment will not work if severe
How to determine if there is joint involvement in a wound in cows?
Position Synovial fluid present - viscosity Explore with sterile probe Radiography +/- contrast Expand synovial compartment - sterile saline, entry away from wound, if saline exits at wound then lavage
Cellulitis in cows: Prognosis?
Guarded - often poor response to treatment
Bone sequestrum in cows: Presentation? Diagnosis? Treatment?
Typically lower leg due to not much most tissue padding
Classically presents as normal wound, starts healing well but have persistent discharging tract
Take radiographs - radiolucent line around a fragment of bone that has lost its association with the bone
Treatment - surgical removal
When is cruciate ligament rupture often seen in cows? Diagnosis? Treatment?
Breeding bull acutely lame with swelling over stifle - drops down to hock over time
Happens at point of dismount
Diagnosis:
- rule out foot/lower limb
- clicking sound
- joint effusion
- pain
- crepitus
- cranial drawer
- radiography: femoral condyles shift back in relation to tibial crest
Box rest if young bull <400kg, likely to develop DJD, ligament replacement (difficult to find material strong enough for a heavy bull)
Patellar fixation (upward) in cows: Presentation? Treatment? Ddx?
Leg fixed in full extension
Adult steers?
BCS no difference
Treatment: cut medial patellar ligament, both legs!
Ddx: spastic paresis: differentiate as if lift leg up can flex it manually, treat with tibial neurectomy, genetic so castrate if male at same time, or if female allow to fatten but don’t breed
Peroneus tertius rupture in cows: Diagnosis? Cause?
Diagnose by pulling leg backwards - fully extended hock, stifled remains flexed (usually both extend/both flex)
Can be caused by pulling leg too high up in crush
Osteodystrophies in cows: rickets and osteoporosis/osteomalacia - difference? Cause and risk factors? Clinical signs? Diagnosis?
Rickets: growing animal at growth plates
Osteoporosis and osteomalacia - mature bone
Mineral/vitamin deficiency: Ca, P, Cu, D - affects calcification and bone formation
Combined with rapid growth, gender, housing, genetics
Clinical signs:
- stiffness/recumbency
- bone distortion (angular limb deformities e.g. carpal valgus)
- long bone fractures
- swelling joints/epiphysis
Diagnosis:
- joint fluid
- bloods low Ca, high AlkPhos
- PME and histopath
- bone ash concentrations on PM
