Lameness Flashcards
What can you add to a ruminants diet if high grain diets to rebalance high P: CaCO3?
Calcium carbonate (limestone)– immediately for growing ruminants, if > 8 weeks full feeding for adults
High serum phosphate from a diet high in cereal grains in growing cattle and sheep does what?
Antagonises serum Ca2+–> Low Ca2+ stimulates PTH–> Ca resorbed from the bone–> tends to cause osteoporosis in sheep and cattle
How can we assess secondary nutritional hyperparathyroidism?
* Urinary P excretion… compare urein: serum % of phosphorous and creatinine (baseline metabolite that the kidney doesn’t reabsorb)
What can happen with low dietary vitamin D?
Vitamin D needed for active Ca & P absorption from gut–> low Ca &/0r P means bone can’t be mineralised–> Rickets in growing animals or Osteomalacia in adults (remodelled bone is soft)
How do you ensure enough vitamin D in a ruminants diet?
Avoid rachitogenic factors (anti vit D) and high NH4 (antagonises dietary Ca absorption) e.g. in oat crops
** can give oral or injectable supplements in young sheep if signs are developing to help in situations of Ca deficiency
* Vit D toxicity causes abnormal tissue mineralization
Keys in a ruminants diet?
* Enough energy, protein, Ca, sunlight, Cu
* Parasitism can have a big effect
* Ca: P balance especially with cereal supplements
How much calcium do you need to add to a diet to fix Ca:P ratio?
How can nutrition affect lameness?
90-90-90 rule?
90% of a herd’s lameness from the feet
90% of those lamenesses are in the back feet
90% lateral claw
Most cattle lameness from what lesions?
Economic losses due to?
Approximate cost of lameness in an individual treatment
$200 per lame cow (1998) in AUS
Average loss of production in a lame cow?
Lameness and reproductive performance?
What percentage of cows that are culled are culled for lameness?
Multifactorial aetiology of lameness in cattle
Predisposing causes of lameness
* Infectious agents- Fusobacterium necrophorum
* Nutrition- rumen acidosis and laminitis
* Hereditary- e.g. cork screw claw, sore ulcer
* most lameness due to over-worn, bruised soles or stones in interdigital cleft
* Increased when farm track had steep slope, course gravel or broken sections
* Bail feeding associated lower incidence lameness
* Cows should not be hurried on farm tracks
** Risk factors on track
- below avg track maintenance, bad cow flow on track (number of congestion points), patience of farmer- motor bikes, biting dogs
**Risk factors in shed
- biting dog, contentment of cows, cow density in yard, aggressive use of backing gate
** Risk factors in animals
- higher Friesians, white feet
Lameness prevalence picture
Examination of the lame cow
* Observe standing free in yard
* History- how long lame, treatment?
* Clean with scrubbing brush, water… hoof knife, rasp or angle grinder
* Look for swelling at the coronary band
* look for defects or penetrations of the sole
* Use hoof testers to check for pain
* Examine for axial, abaxial wall cracks
* Thoroughly explore any defects detected
8 point exam
- Which leg is the cow lame in?
- Is the leg swollen and obviously painful above the hoof?
- Are cracks present in external surface of the hoof wall of lame leg?
- Is there soft tissue swelling with foul swelling discharge and dead and damaged skin in the interdigital space?
- Is there abnormal discolouration in the sole horn? Do not confuse with normal pigment (usually black)
- White line- expanded and filled with mud and gravel especially towards heel area?
- Are there any sensitive areas which cause withdrawal reflex?
- Seek vet advice OR withdrawal response detected– bruising- rest; toe/foot abscess or under run sole- trim, pare, grind until loose sole horn removed back to normal horn; pus detected- establish drainage
How do you lift the hind foot? What is a good idea if there is hindfoot lameness?
* possibly low dose Xylazine with hindfoot
How do you lift the front foot?
* Loop around leg at level of dewclaws
* over rail and back under axilla
* then back over rail and lift
What’s the difference between Holstein and Friesian?
Holstein Friesians are a mixture
Holstein are bigger girls– genes from North America
Friesian gene is from Europe
** our herds are a mixture of the two so a middle size
Why are angle grinders potentially dangerous?
* Electricity and water- use circuit breaker
* Only use on well restrained animal
* Must wear safety goggles
* Can generate excessive heat- proceed slowly
* Not recommended for use on front feet of standing animal unless very well restrained
Examination of a lame herd
** A lameness problem on a farm needs to examine farm management factors in the herd rather than treating a long series of individual lame cows
* Define the problem– how many cases, what are the lesions
* Ascertain likely aetiological factors– farm tracks, animal handling, general farm environment, nutritional– SARA and laminitis
Principles of treatment of lame cows
* Adequate restraint +/- sedation
* Appropriate anaesthesia
* Suitabe equipment
* Avoid walking lame cows too far
Anaesthesia of the bovine digit?
* Xylazine an excellent sedative
* Interdigital nerve block- 20 cc lignocaine injected between the digits
Regional intravenous anaesthesia?
* Regional intravenous anaesthesia:
- apply tourniquet
- 20 cc lignocaine IV in digital vein
White line disease (25%)?
* Disintegration junction between sole, wall
* Penetration dirt, stones at this site
* may track up to coronary band
* Usually lateral claw hind digit
* Variable lameness
Sole injury (26%)?
Sole penetration, abscess, under-run sole
* Infection through FB or horn defect
* Acutely lame
* Characteristic “sliding” lameness
* Swelling above coronary band (may be very slight)
* Careful search for hoof defect
Axial wall cracks (19%)?
* Occur adjacent to axial groove of medial claw of hoof
* Often no lameness
* Lameness often follows heavy rain- fine mud forced into crack
Footrot (infectious necrobacillosis 10%)?
* Footrot- Fusobacterium necrophorum
* Necrotising infection interdigital dermis, cellulitis of digital area
* Signs
- sudden onset lameness VERY PAINFUL
- swelling affected area
- responds antibiotics
Bruised sole?
* Commonly affects hind feet
* Sole worn flat
* Sole may be palpably thin
* Bruising, haemorrhage evident
Excess hoof wear?
* Feet kept moist due to environmental conditions
* On concrete at time of milking
* Plus walking laneways
* May lead to excess hoof wear
Sole ulcer?
* More common in housed cows
* Specific lesion sole/bulb junction, usually nearer abaxial margin
* Lateral hind claws
* If exposed dermis, granulation tissue commonly develops at defect
* Treatment- expose diseased tissue, remove necrotic horn
Inter-digital dermatitis?
* Cause- bacteroides nodosus
* Can produce benign footrot sheep
* Inter-digital dermatitis, but little swelling
* Often affects more than one foot, calves particularly susceptible
Digital dermatitis (Hairy Heelwart 1%)? Clinical Signs?
* very painful, contagious disease causing wart-like areas on the back of the hind feet, on the bulb of the heel or near the interdigital cleft
* Common in dairy herds in the US, uncommon in AUS at the moment
* precise cause is unknown, Bacteroides species and an invasive Treponema spiroacheate have both been implicated
* Clinical features- lesions of digital dermatitis can be of at least two distinct types: erosive/ reactive (strawberry like) and the proliferative (wart-like) forms– US, EU, Chile now seeing non-healing lesion; cleansing exposes reddish granulation tissue (strawberry) with concave profile); lesion is very sensitive and easily bleeds but the soft tissue is not swollen; animal is often lame; proliferative form may give rise to the papillomatous type, which is characterised by a mass of hard, fine tendrils which can be several cm in length and cover a considerable area
Interdigital skin hyperplasia?
* Excess epidermal, hypodermal tissue
* More common hind feet
* Appear as protuberance of skin
* Degree of lameness varies
* Treatment surgical
Aseptic Laminitis?
* Diffuse aseptic inflammation of the corium
* Laminitis is inflammation of the soft tissue between the hoof wall and the sole and the underlying pedal bone within the claw
* Inflammation results in a reduction in the quantity and quality of hoof material produced
Acute laminitis?
* Acute laminitis is not common in cattle in our environment- may follow acute illness
* Clinical signs similar to horse, but more variable
* Affected animals
- move slowly, arched back
- stand with hind legs extended forward, fore legs forward
Subclinical laminitis
* Occurs much more commonly than acute laminitis
* It’s an important cause of other hoof diseases, for example, white line disease, sole abscesses, sole ulcer and claw deformities
* Produces no immediate signs but is recognized by the changes in the hooves which occur several months after episodes of sub clinical laminitis– claw changes shape, becomes longer and the front wall of the hoof is concave when viewed from the side… sole becomes wider and flatter, wall develops horizontal ridges or ripples due to partial interruptions in its production
* Changes are a deterioration in hoof horn quality and haemorrhages in the sole of the hoof
* The white line develops a yellow colour and has small red dots of haemorrhage along it
Subclinical laminits/ chronic laminitis
Sand Crack- vertical split in the hoof wall extending from coronet to a variable distance along the direction of growth
* Large incomplete sandcracks often not associated lameness
* two distinct vertical fissures– fissures of coronet, fissures of wall
* Horizontal fissures of hoof wall– discontinuity of wall of hoof in a plane parallel to coronet
- often occurs in all hooves
- related to severe upset of metabolism– mastitis, metritis, other acute diseases
Abnormalities of hoof growth
Indications of amputation of a digit? Considerations?
Could be?
Applying blocks or cowslips
* Clean (defat) area with alcohol
* Mix glue and use this to attach block or cowslip
* Keep foot restrained until glue dry
* must be sure the claw is sound
* Use angle grinder to clean sole, walls. Place shallow grooves on sole
Footblocks
* Wood or rubber blocks attached to the sound claw opposite the affected claw of the lame foot
* Block attached to sound claw with Bovibond
* Very effective, well accepted by farmers
Diagnosis? Treatment?
Coxofemoral luxation
* Dianosis: stance of animal, crepitus is usually evident, palpation head of femur, affected limb abducted excessively, palpate greater trochanter– upwards and forwards, upwards and back, downwards and forward- rectal, downwards and back- rectal
* Treatment- sedate heavily with Xylazine… lateral recumbency, affected limb uppermost, restrain the animal with rope through inguinal region, traction- block and tackle or calving jack…. rotate limb while applying traction, can change direction of traction if needed, feel clunk– immediately release traction
** Better prognosis if cow able to stand before reduction, cow less than 3 years, less than 400 kg, duration dislocation less than 12 hours
Pelvis fractures– body of ilium, ischium or pubis
* rest
* beware of risk bony callus- dystocia
Partial or complete separation joint surfaces sacrum, ilium
* Mild cases- slight ataxia, knuckling fetlock
Patellar luxation
* Patellar temporarily fixed on upper part of femoral trochlea
* Clinically the animal progresses with jerky action, leg remains extended back until patellar frees itself
* Treatment- medial patellar desmotomy (incision or divison of a ligament)
Patellar luxation- correction:
* Identify middle and medial patellar ligaments
* Prepare area anterior to and over medial patellar ligament for surgery
* local anaesthesia
* 1.5 cm incision just anterior to medial patellar ligament, insert tenotome beneath medial patellar ligament, incise ligament completely, clunk, suture skin
11? 12? 13?
Peroneal paralysis- susceptible where it runs down over the lateral femoral condyle, head of fibula
* knuckling of fetlock, over-extension of hock- in severe cases dorsal aspect fetlock joint contacts the ground
*very little effect on the middle group of cows in the mob
* Overall speed of herd will hardly change- this is set by the dominant cow group in the herd
THEREFORE
* impatience and attempting to hurry cows will save little time
* but may lead to a marked increase in a number of lame cows in the herd
What else can present a problem?
* Exits from the dairy can also present a problem
Stage one– trim the medial toe to the correct length- commonly the dorsal wall at the toe measures 75 to 80 mm… the lateral toe is then trimmed to a similar length
Stage two– remove excess sole horn- most importantly at the toe.. the weight bearing services across both toes should be flat and balanced
Stage three– equalize weight bearing on the medial and lateral claws
Stage four– remove the axial ledge- the central sole area beneath the flexor tuberosity over the pedal bone should be non-weight bearing
Stage five– if necessary remove excess overgrowth of horn heel horn, commonly on the outside the heel of the hind limb
