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
White muscle disease in cows: Aetiology? Age? Trigger? Serum changes?
Vitamin E and selenium deficiency
Rising 1yo
Trigger: increased activity e.g. when released into field
Serum levels: low vit E and Se, high AST and CK
Hip dysplasia in cows: breeds more often affected? Age seen?
British natives, Charolais, Aberdeen Angus, South Devon, Galloways
3mo-2yo
Bilateral - one leg often worse
Dorsal acetabulum and femoral head
Osteochondrosis in cows: Aetiology? Stages? Presentation? Diagnosis?
Aetiology uncertain - poss genetic O dissecans O latens O manifesta Little lameness until OCD Often bilateral - atlanto-occipital and femoro-patellar joints Diagnosis: - joint tap: mild inflammation, mild inc protein
Degenerative joint disease in cows (DJD): What is it? Joints affected?
Severe, progressive diffuse cartilage lesions
Distal interphalangeal joint in calves
Fetlock, carpus, tarsus
Dislocated hip in cows: Presentation? Direction? At risk time? Treatment?
Reduced anterior phase of leg
Swelling of greater trochanter
Most common is dorso-cranial - still walking
Second common is ventro-caudal - recumbent
At risk after calving
Treatment by closed reduction - 40-75% prognosis, walking normal in 3-4d
How can ultrasound help differentiate between a haematoma and an abscess?
Clear fluid suggests haematoma
Echogenic fluid suggests abscess
Causes of fractures in cows?
Trauma
Spontaneous - hypophosphataemia
Pathological - infection/necrosis
Mc/Mt fractures in calves - cause? problems?
Mc/Mt fractures from calving ropes
Deep sedation/GA to realign and cast
If blood supply has been disrupted will fail to work (can’t predict)
How to splint fractures in cows? How to transport?
Lower limb (below just above carpus or below hock): 2 splints Between carpus and elbow or hock and stifle: 1 lateral splint Above elbow or stifle: no splint Transport with good legs forward
Prognosis of fractures in cows?
Young better Distal better Closed better Simple better than comminuted Ambulatory better than recumbent
Options for fixing/treating fractures other than simple
splints in cows?
Box rest for humerus/femur if no displacement or joint involvement and animal is ambulatory (cull if not)
Amputation - depends on meat price
External co-aptation below elbow and hock
Hanging limb pin cast (trans-cortical pins) - pins above fracture only, full leg cast, include foot
Thomas extension splint
External fixation
Internal fixation
Complications of fractures in cows? What to do when removing support?
Osteomyelitis Dislocation/non nunion Reduced long bone development Ischaemic necrosis Nerve damage Disuse atrophy
Gradually reduce support by bandaging/box rest etc to rebuild muscle
Causes of septic arthritis in cows? Clinical signs? Diagnosis? Treatment?
Haematogenous - umbilicus, intestines
Traumatic
Clinical signs: pain, effusions, lame
Diagnosis: arthrocentesis with 16G needle as pus thick (high protein and cell levels, poss pus)
Conservative treatment - aggressive ABs, anti-inflammatories
Surgical - GA, IVRA, lavage, arthroscopy, arthrotomy
Hygroma in cows: Cause? Treatment?
Inadequate bedding or poor cubicle design Excessive pressure on hock/carpal joints Clip and prep Local infiltration Incision top and bottom Break down septa and drain Lavage Pressure bandage
Indications for digital amputation in cows?
Deep digital sepsis/sepsis arthritis of the distal interphalangeal joint
Complications associated with sole ulcers, white line abscesses, foul in the foot, penetrating injuries
Retroarticular abscess
Non healing wall lesions
Toe necrosis
What are the 3 methods for digital amputation in cows? Prep?
Method 1 = disarticulation of proximal interphalangeal joint Method 2 = cut through middle phalanx - not indicated (disruption of blood supply to the part of the second phalanx that is left/prolonged recovery) Method 3 = cut through distal proximal phalanx
Wash and disinfect food
IV regional block
Bandaging after
What is arthrodesis? Method?
Alternative to digital amputation
Fusion of one of the interphalangeal joint -> pain eventually then goes
Incise at heel bulb Usually remove navicular bone Drill through joint Takes time for joint to fuse Need drains
Wash and disinfect foot
IV regional block
Block unaffected claw
Post op care for digital amputations and arthrodesis in cows?
Dressing changes
Antibiotics
Analgesia
What can go wrong with digital amputations and arthrodesis in cows?
Poor post op care Problems with remaining claw (amp) Ascending infections Chronic pain Failure to achieve ankylosis of the joint (arthrodesis)
Signs of cattle being in pain?
Attempts to minimise pain: - reduced activity - lying down - reduced load - posture Clinical signs: - HR, RR, temp - food intake, body weight, impaired rumen function - mentation (dull, depressed, little interest in surroundings) Communicate pain: - cow's stoical nature - vocalisation, facial expression
Clinical signs of lameness in cattle?
Arching of spine Hanging or nodding head as she walks Shortened stride length Adduct/abduct hind limbs Paddling and shuffling feet Unwilling to walk Reduction in weight bearing of affected limbs Highlight a lameness by gently walking up and down a slope
Why are lame cows thinner and thin cows more likely to become lame?
Lame -> thin: DMI falls due to: - increased lying times - less time spent eating - less meals/day - pain/reluctance to walk to feeding areas Thin -> lame due to: - thickness of digital cushion - increased metabolic load - BCS<2.5 has increased risk for lameness in next 2 months (so best to maintain BCS 2.5+)
How long must medicines record be kept for legally for cows?
3 years
What is the transport legislation for farm animals?
Not fit for transport if ‘unable to move independently without pain or to walk unassisted. Injured or present physiological weakness or pathological processes’
Lame animal cannot be transported
DEFRA welfare codes for lameness which are not a legal requirement but can be used to support prosecution?
Very lame cows should be taken off concrete and placed on a suitably bedded pen
If lame cow does not respond to treatment a vet must be called immediately
If a lame animal does not respond to the vet’s treatment, should be culled rather than left to suffer
Which NSAID has no milk withdrawal?
Ketoprofen
How long should cows lie down with comfortable well designed cubicles (therefore less lameness)?
12-14 hours/day
What is the best cubicle bedding for cow comfort?
Deep sand bedding
How does stocking density affect cow behaviour? Ideal resting area per cow in straw yards? Number of cows per cubicle?
Overcrowding -> increased standing times and more aggressive interactions between cows
Straw yards - at least 10 square metres resting area per cow, 10-15m for transition
Cubicles - stocking density at 100% or less
How big should the feed barrier space be per cow?
76cm yokes, one/cow
70cm when not using yokes
75-100cm for transition cows
Why is calving a risk factor for lameness?
Weakening of the connective tissue of the claw suspensory apparatus
So increased susceptibility to SU and WLD
Why are transition cows more susceptible to lameness?
Reduced DMI, fat mobilisation
Diet changes
Scoring of hock lesions in cows?
Score rear hock (one or both) of 20+ cows
Work out % of cows with each score
Score 1 = no swelling or missing hair
Score 2 = no swelling, bald area
Score 3 = swelling evident or a lesion through the hide
When should routine foot trimming be done in cows?
At drying off, 60d before first calving
60-100d in milk
And always as soon as lame - that day!
Ideal BCS at calving?
3
How often should footbaths be used in a herd of cows?
?
Effect of lameness of fertility of cows?
Delayed cyclicity
Prolonged CI and calving-conception intervals
Ovarian cysts
Less likely to conceive
Costs of lameness? Average cost per affected cow?
Treatment costs: drugs, vet, milk withdrawal Labour costs Reduced yield/repro performance Involuntary culling/low carcass quality £273/cow
What makes up the suspensory apparatus of the digit in cows? What can this be compromised by?
Collagen fibres keeping pedal bone attached to dermal lamellae
Can be compromised by increased activity of matrix metalloproteinases (MMPs)
What is the white line?
Junction between wall horn and sole horn
Foot and mouth disease: Type of virus? Animals affected? Signs?
Cloven hooved animals - cattle, pigs, sheep, goats Highly infectious Aphthovirus Signs: - fever - lameness - tongue, feet, snout and teat lesions - high morbidity, low mortality
Prevalence of bovine digital dermatitis?
70% of UK dairy herds have it
Prevalence of 40% on each farm
Economic costs of bovine digital dermatitis?
Milk drop
Treatment costs
Increased culling rate
Increased labour costs
When is bovine digital dermatitis usually seen?
Housing periods
Rear feet
Features of treponemes?
No virulence factors identified yet
Fastidious anaerobes which require complex media supplemented with serum for growth
Infection reservoirs/transmission routes for bovine digital dermatitis?
Ruminant GI tract
Slurry
Direct contact
Foot trimming equipment
Which condition of dairy cows occurs because the suspensory mechanism within the claw horn capsule has been disrupted around calving and poor management has hindered the remodelling of connective tissue, particularly of the lateral hind claw?
Overloaded claws with associated sole bruising
Which condition is this:
- found in breeding stock mainly, affecting individual pigs.
- E.g. when on concrete floor in wet underfoot conditions with little straw bedding.
- Now severely lame putting no weight on leg.
- Affected foot is vert swollen and painful.
Deep sepsis affecting the navicular bursa or digital flexor tendon
A cause of lameness seen in individual cattle, mostly when they are outside at pasture. For example, a 22 month-old Hereford-cross steer was found severely lame whilst outside at grass along with 15 other similar cattle. Its right hind leg was affected. Visual examination of the limb, before it was restrained, revealed the limb below the fetlock was very swollen, particularly around the heel.
Inter-digital skin lesion, which presents as a necrotic focal epidermitis; the animal is often acutely lame
Which condition is this:
- milking goat
- lameness of forelimb
- horn capsule has separated from the skin at the coronary band in the middle third of the abaxial wall
- dirt and debris has impacted where the wall and sole meet and in the middle third of the foot
White line disease with abscess which discharges at coronary band
