Ruminant Lameness Flashcards
Why do we care about lameness in ruminants?
1) 20-50% of dairy cattle have some detectable gait abnormality
2) Second most common clinical disease
3) Third most common reason for culing
4) 20-30% of sheep operations have foot rot
What is the estimated cost of clinical lameness in dairy cattle
$500 per case
costs
1) treatment
2) reduced milk production
3) Reduced fertility (increased days open, increased days to firsts service, increased number of services/conception)
4) Culling
5) Death loss
What are the animal welfare concerns with lameness in ruminatns
lameness interferes with an animal’s ability to exhibit natural behaviors by altering lying time, social itneraction, ovarian acitivty, estrus intensity, and possibly rumination behavior
*producers and vets have a certain obligation to produce an ehthical product and minimize harm
an consumer and retailers have vested interest in animal welfare
90% of ruminant lameness is due to
problems in the foot
(two digits of the limb in artiodactyls)
therefore it means that these issues are in one or both digits of the limb and distal to fetlock
What does foot mean in ruminants
anything distal to the fetlock, not just structures within the hoof capsule and P3
What causes foot issues in ruminants
50% infectious
-foot rot, hairy heel warts (digital dermatitis), interdigital dermatitis
50% non-infectious: originating from hoof conformation issues
In ruminants, is the keratin of the sole or the keratin of the hoofwalls softer
keratin of the sole
-animals need to be walking on the hoofwall
What is the white line in the ruminants hoof
the junction between the vertical hoof walls with the sole
highly vascular and innervated tissue that provides nutrition to the hoof
dense matrix of connective tissue -connects the basement membrane of the dermal epidermal junction to the periosteal surface of P3 and thus suspends P3 from the innerwall of the hoofcapsule
corium
What connects the basement membrane of the dermal epidermal junction to the periosteal surface of P3
Corium
-thus suspens P3 from the innerwall of the hoofcapsule
What attaches bony P3 to the hoof capsule
Laminae
in the wall and tightly attached to lateral and cranial portions of P3 and interdigitate with insensitive lamina in the hoof capsule
sensitive laminae
Why do ruminants have a smaller laminar region of the digit compared to horses
because they have less surface area of contact per unit of supported weight
Conditions that disrupt the corium will result in
significant pain! and non-weight bearing
In ruminants,
The fetlock is __________________ while the pastern joint is ______________
fetlock is proximal to dewclaws
pastern is roughly halfway between coronary band and dewclaw
In ruminants, what might penetrating wounds and deep ulcers or abscess of the heel cause
secondary infection of 1) navicular bone and bursa
2)coffin joint
3) digital flexor tendon
helps fix the bony column in vertical formation and pulls the tip of P3 ventrally transfering the weight forward
deep digital flexor tendon
a complex arrangement of fat deposits between P3 and solar corium (lamina)
cushion and distribute weight trasnferred to the sole
-thickest at heel
-helps with vascular and lymphatic return
Digital cushion
In ruminants, the digital cushion is thickest at the
heel
In ruminants, what is normal growth rate of hoof
5-6 mm per month
influenced by Nutrition, lactation, gestation,cycle, season, substrate/footing
Positive influences on hoof growth
copper
zinc
iron
biotin
What diet in ruminants leads to ruminal acidosis and laminitis (coritis)
excessive carbohydrate in the diet
In ruminants, what hoofs bear more weight
Front feet: medial claws
Hind feet: lateral claws
In the front limb, hoof lesions are more often to occur in the
medial claws - animal bears more weight
In the high limbs, hoof lesions more often occur in the
lateral claw- animal bears more weight
How can you identify a foot-sore ruminant from a distance
1) Arched back
2) Ears are back
3) Restless, shifting weight, tail flicking constantly
4) head position is variable
What is seen with footpain
when touching it with a jet of water or a stick, the animal will rapidly flex the joints of the upper limb to bring the foot up off the ground
How do you notice ruminants with upper limb pain
hesistant to to flex those joint and move those bones and soft tissues.
they will hold the joints in neutral, slightly bent posture and move those joints minimally as they walk. Short anterior phase to the side
How do you distinguish between upper and lower limb pain in ruminants
Lower limb: animal will rapidly flex the limb upwards when touching it
Lower limb: joints held in neutral and will move the joints minimally as they walk
What is seen with medial claw pain
more often the forelimb
it may adduct the limb in order to place more weight on the sound lateral claw
What is seen with lateral claw pain
more often the hindlimb
may abduct the limb in order to place more weight on the sound medial claw; the limb may be held slightly outward rotated position as well
Is abduction seen with medial or lateral claw pain?
lateral claw pain
Is adduction seen with medial or lateral claw pain
medial claw pain
what is a great tool for detecting generalized soft tissue swelling in the ruminant foot **
Dewclaws - compare with the contralateral limb
dewclaws are anchored in soft tissue of the digit, if it swells, the dewclaws will spread apart.
How might you differentials differ with bilateral dewclaw swelling vs unilateral *
Bilateral - more likely interdigital disease (eg bovine foot rot)
Unilateral - more likely septic synovial structure
why are the dewclaws in ruminants a helpful method in assessung swelling
they are loosely anchored in the soft tissues, they are spread further apart in the swollen foot versus the non-swollen foot.
Bovine lameness scoring systems
1-5
1= normal, level back, no lameness
5= significant lameness
modification with feedlot animals as you cant get as close to them
you have a cow with a base-wide hindlimb stance. In what limb and digit does this cow have pain?
hindlimbs, bilateral (lateral claw) disease likely
but get more information on movement
How do you examine the cow’s foot
Restraint is key
1) Tilt tables- common in dairies, puts far less back/low back strain on the individual
2) Ropes- limb that is to be worked on is secured with ropes to the side bars of the chute/stocks
3) Standing chute or stocks
How do you examine the foot of ruminants
1) Wash surface of foot
2) If sole remains dirty, use hoof knife to remove superficial layer of horn
3) Look at the white line as it is a common area for lesions
4) Hoof testers - sole, heel, and hoofwall
non-painful one first, re-apply to see if it repeatable and increase confidence of results
5) Palpate each digit - flex and extend
6) Examine the sole for any dark colored defects
When using hooftesters in cattle, what limb do you want to do first
non-painful claw and limb first
get the cow used to the pressure of the hoof tester so that it increases the likelihood that they are demonstrating a response to discomfort rather than a response to a new stimulus
What do dark-colored defects on cow’s sole indicate
sole absceses- any defects should be carefully pared out with a hoof knife to determine if there is any underlying exudate
How often should ruminant hoofs be trimmed
Dairy: recommended 2 times a year
Beef/Small Ruminants: vaires by operation, terrain, and distance traveled
When hoof trimming ruminants, how much should you trim
Trim to a length of 7.5-8cm
add 3mm for each 75kg over 750kg
maintain adequate sole thickness of ~5mm at the toe tip
excessively long toes shifts weight bearing in the
palmar/plantar direction
puts it over the softer heel horn, can lead to bruising or pressure necrosis of the heel horn
also increased strain on flexor tendons
Sole ulcer/Rusterholz ulcer
an ulcer that is caused by pressure necrosis of the heel horn by overgrown claws sifting the weight bearing in the palmar/plantar direction
ucler could allow bacteria to colonize deeper structures like the DDFT sheath, navicular bursa, coffin joint, etc.
What are the result of overgrown claws in ruminants
1) Weight bearing shifted in palmar/ plantar direction
2) Sole ulcer (could allow bacteria to colonize deeper structures of DDFT sheath, navicular bursa, coffin joint)
3) Increased strain on the flexor tendons
What may result of the entire thickness of the corium undergoes pressure necrosis
it may allow surface bacteria to colonize the digit deep to corium
corrective trimming
the well trimmed foot has a center of weight bearing that is moved more toward the center of the digit where the sole horn is much thicker and there is additional weight bearing support provided by the hard vertical walls of the center of the hoof
What are the 4 most. common causes of foot lameness in ruminants
1) Digital dermatitis (hairy heel warts)
2) Laminitis
3) Sole abscesses
4) Interdigital necrobacillosis (foot rot)
The most common cause of lameness in dairy cattle *
Digital dermatitis
What are other names for digital dermatitis
hairy heel wart
strawberry goot
verricois dermatitis
digital warts
interdigital papillomatosis
What causes digital dermatitis in cattle
Contagious polybacterial disease
-Treponema spp. involved
-Bacteria invade epidermis
T/F: Treponema alone causes digital dermatitis
False- Tremonema is thought to be the cause but several studies investigated potential role of D. nodusus, F necrophorum, bacteroides, porphyromonas spp
With digital dermatitis, what does the lesion look like
Starts as red, eroded granular lesion, exudative, hairs at periphery matted
Progresses to look like a big wart with raised conical projections of epithelium (blackened keratin)
typically in the palmar/plantar aspect of the interdigital skin and/or skin just above the heel bulb
lesion progresses over time, takes 130-150 days
Where does digital dermatitis typically occur in cattle
palmar/plantar aspect of the interdigital skin and/or skin just above the heel bulb
What will early digital dermatitis lesions look like
red, eroded granular lesion, exudative, hairs at periphery matted
What will late digital dermatitis lesions look like
Big wart: skin responds to bacteria erosion with hypertrophy over 1-3 weeks
Raised conical projections of epithelium- can have blackened keratin extending 1-1.5 cm from surface (hairy wart stage)
NO generalized soft tissue swelling
T/F: no generalized soft tissue swelling is seen with digital dermatitis
True- only epidermis involvement
Do early or advanced digital dermatitis lesions shed more organisms
advanced
Will you see dewclaws being spread apart with digital dermatitis cases
NO - no soft tissue swelling
Is digital dermatitis more common in the front or hind limbs?
Hind feet more common- likely more exposure to manure/urine, lower hoof angle, more potential for trauma from stall mats even when the cow is lying in normal position
What changes to the hoof is seen with digital dermatitis over time
hoof can be misshapen
-short, rounded toes
-longer heel
-weight off loading
Risk factors for digital dermatitis
1) Poor hygiene and wet conditions- excess manure and urine
2) Early lactation animals: immune suppression of parturition and lactation
3) Introduction of new animals
4) Fomite spread - biosecirty is very important as it is a contagious disease
What can be a fomite for digital dermatitis
traveling hoof trimmers
How do you treat digital dermatitis
1) Isolation if possible
2) Topical oxytetracycline or antiseptics
3) Flunixin meglumine or aspirin if significant pain/lameness
with treatment, lesion and lameness improve in 2-5 days
recurrence is common (infection does ot produce protective immunity)
What antibiotic can you use to treat digital dermatitis
Topical oxytetracycline
topical is good because it is just the epidermis, PO antbiotics are not needed, they may work but will have to observe withdrawal times
What is the withdrawal time for topical oxytetracycline
no milk withdrawal but may want to stil consider testing the milk
can have contamination depending upon handling/milkers
How do you prevent and control for digitial dermatitis
spray feet with topical disinfectant, antiseptic or antibiotic - spray the palmar and plantar aspect of the interdigital skin, spray as soon as you can when the milking process begins
typically in milking parlor
footbaths- with clean feet first, not as ideal
clean hoof trimming equipment and other potential fomites
vaccine- of treponema spp (ineffective
T/F: The Treponema spp bacterin vaccine is effective against digital dermatitis
False- it is polybacterial (other ocmponents are at play)
Digital dermatitis is typically on the hind feet but when it is on the front feet it commonly occur
on the dorsal aspect
Why do topical antibiotics like oxytetracycline work to cure digital dermatitis
because the bacteria only invades the epidermis
laminitis is inflammation of the lamina but inflammation is seen in more than just the lamina as it is
laminar corium
coritis - inflammatory insult affecting coronary, laminar, perioplic, and solar regions of the corium
inflammatory insult affecting coronary, laminar, perioplic, and solar regions of the corium
Coriosis (Coritis)
With coriosis, what makes the hoof walls weaker and abnormally formed
involvement of the coronary corium accelerates the growth of wall horn and altered blood flow reduces keratinization of horn cells
dorsal walls are concave and axial/abaxial walls are flattened
What is specific about horn produced in subclinical coriosis
horn being produces is softer and may appear yellowish or reddish in color as a consequence of poor keratinization and staining by transudates that leak into extravascular tissues
Laminitis is primariy a degenerative or inflammatory process in CATTLE
degenerative
inflammation is largely a secondary event occuring subsequent to an increase in interstitial tissue pressure associate with vascular events of vasodilation, congestion, transudation and diapedisis occuring within corium
laminitis in cattle is highest in cattle that
fed high concentrate diet
-High producing dairy cows (peripartum period and 100 days of lactation)
-Feedlot calves
-Show animals
check the diet for an underlying cause is ruminal acidosis
What diet causes laminitis in cattle
too rich in rapdily fermentable carbohydrates (starches and sugards)
-less saliva (bicarb)
-increased fermentation
In dairy cattle, when is laminitis most common
Peripartum period
-peak incidence of claw lesions at 100 days of milk
What is the pathogenesis of laminitis in cattle
1) Increased readily fermentable CHOs causes die off of microflora
2) Steprotoccus bovis and Lactobacillus increade in number, causing rumen acidosis
3) Bacteria translocation
4) Vasoactive compounds, endotoxin and inflammatory cytokine act on vasculature of laminae, leading to inflammation and degeneration
5) Reduced oxygen and nutrient delivery to corium
6) Corium may stop producing hoof or product poor quality hoof
What overgrowth of this bacteria cause rumen acidosis
Streptococcus bovis
Lactobacillus spp
What factors might contribute to rumen acidosis and subsequent laminitis
-Sorting of ration
-Lack of effective dietary fiber
-Inability ot buffer
How does inflammation and degeneration of the laminae cause hemorrhage into the sole
the affected areas of the laminae can lose their attachment to the overlying horn creating dead space that fills with blood from leaky, inflammed laminar vessels
this can be seen as streaks of hemorrhage in the sole and along the white line
when sole abscesses develop along the white line
“White line disease”
“White line abscesses”
How does laminitis lead to sole abscesses
whe the overlying horn separates away from the inflamed laminae and crack open, creating pockets that can be colonized by bacteria
How does laminits event cause white line disease
1) Laminitis weakens the sole-wall attachment at the white line
2) White line can split open and allow bacteria to enter, creating an abscess
laminitis can induce separation of the white line anywhere along its circumeference of the sole of the foot
T/F: laminitis can induce separation of the white line anywhere along its circumeference of the sole of the foot
True
White Line disease
weakened, defective, or poor quality horn
-prone to separation ad bacterial/fungal colonization
stones, debris, manure entrapped in the white line that can move deeper into tissue
bacterial colonize the region
abscess forms
a term for there being an abscess at the white line that ascends between the corium and the hoofwall, and the abscess ruptures out at the coronet
“Gravel”
hardship rings are visible
weeks after bout of laminits
represent prior interruption of hoof production by germinal cells of laminae
hoof grows 5-6 mm per month, takes time to see lines and ring.
rings associated with past insult in normal hoofwall growth
hardship rings
T/F: acute laminitis is rare in ruminants
True
What does acute, severe laminitis look like in ruminants
pain of all four feet, arched back
walking on eggshells gait
pain
recumbent for far longer than horses
defects in the hoofwall that lead to subsequent, secondary condition such as white line abcesses
How do you treat laminitis in ruminants
Acute phase: NSAIDs, deep bedding
Pare out any abscesses- regional anesthesia
Prevention: Nutritional management to prevent ruminal acidosis
In ruminants, sole abscesses develop subsequent to
1) Laminitis
2) Sole ulcers
3) Penetrating wounds
4) White line disease
results from introduction of environmental bacteria through the hoof horn or subsequent to systemic changes in the microvasculature of the hoof
What causes pain associated with sole abscesses
focal pressure and inflammation on the corium/ sensitive laminae
What are common locations of sole abscesses
Hind feet- lateral claw
front feet- medial claw
Do sole abscesses have generalized soft tissue swelling?
NO- unless it spreads to deeper tissues involved
How do you ID sole abscesses in cattle
apply pressure
-can be pinpoint sized entire
-pare out all dark discolored areas with a hoof knife
How do you treat ruminant sole abscesses
1) Local anesthesia
2) Using top of curved hoof knife- extirpates pus pocket to ensures complete drainage of all trapped pus
3) Cone shaped paring of abscess and adjacent horn- prevent sole defect from sealing over and re-trapping bacteria
3) Apply hoof block to unaffected claw via epoxy
4) NSAIDS
5) Systemic antibiotics typically unnecessary unless abscess extends deep in corium
6) No bandages
How should you pare out a sole abscess?
Cone shaped paring of abscess and adjacent horn- prevent sole defect from sealing over and re=-rapping bacteria
Why is a hoof block applied to the unaffected heel in sole abscess treatment
take weight bearing off of the affected digit unless some hoof horn can grow back in over the pared away lesion
wooden bloc kcan be left on until it wears down in a week or two
In sole abscess treatment, systemic antibiotics are unnecessary unless
typically unnecessary unless abscess extends deep in corium
Should you bandage sole abscesses in ruminants
No- do not place a bandage as you want the infected material to drain out of the abscesses
What bacteria causes bovine foot rot
Fusobacterium necrophorum
What are other names for bovine foot rot
interdigital necrobacillosis
interdigital phlegmon
foul of the foot
gram negative anaerobe, normal inhabitant of GI tract
causes bovine foot rot
Fusobacterium necrophorum
very malordorous
Pathogenesis of bovine foot rot
1) Interdigital skin damaged
2) Wetness and feces (maceration) and abrasions lead to Fusobacterium necrophorum to colonize
3) releases potent toxins to induce necrosis and inflammation of the interdigital skin
4) Anaerobic- enables organism to multiply and spread through the deeper layers of dermis and into the SQ tissues
What causes entry of Fusobacterium in bovine foot rot
Maceration- softened skin and prolonged moisutre exposure
Physical trauma- abrasions from rough ground, coarse sand, frozen mud, low-lying cacti and rocky ground
Is bovine foot rot contagious
NO - environmental components
-moisture and poor hygiene (pens with poor hygiene and pastures- areas of congregation)
no protective immunity from prior infections - can have recurrence
What environmental conditions is conducive to BFR
warm, moist
T/F: there is no generalized swelling of the foot in bovine foot rot
False - symmetrical generalized swelling of the foot
What does the lesion of bovine foot rot look like
-Symmetrical, generalized swelling of the foot
-Fissure in the interdigital skin with underlying tissue necrosis (dark in color)
-May have watery exudate
-Stinky (anaerobic)
Bovine foot rot diagnosis
Acute onset lameness
-Symmetrical, generalized swelling of the foot
-Fissure in the interdigital skin with underlying tissue necrosis (dark in color)
-May have watery exudate
-Stinky (anaerobic)
What kind of swelling does bovine foot rot cause *
swelling that is symmetrical down the axial midline of the foot
the interdigital space is on the axial midline so soft tissue swelling is originating from and centered on this region
How do you treat bovine foot rot **
Parenteral antibiotics (topicals wont work)
-Ceftiofur
-Oxytetracycline
-Penicillin
-Ampicillin
-Florfenicol
-Tulathromycin
-Tylosin
-Sulfadimethozine
NSAIDs for pain
Do not bandage (anaerobe and they will like it more)
What topical antiobiotic do you use to treat bovine foot rot *
NONE- they will not work, can use as aid (Copper or zinc)
bacteria is located deep in the skin and SQ space so these will not reach the wound
Why might oral antimicrobials not work with cattle
1) Rumen microbes may degrade the antimicrobial
2) even of they do not, absoption of AB from ruminant gut is slowed by the need for drug to pass through all 4 stomach chambers so you get delayed in getting high ECG levels
What might occur if the swelling and lameness fro BFR does not resolve in 1 week or less
1) Misdiagnosis
or
2) Complicated BFR- infection can spread to deeper structures leading to deep sepsis or DIP joint of P3 bone)
Septic DIPJ
can occur due to failure of diagnosis and prompt treatment of bovine foot rot
-extensive debridement of infected bone, cast application, and a prolonged course of analgesic and antibiotic therapy to induce ankylosis of the infected coffin joint
-could also do claw amputation but the other digit is going to break down other time
T/F: artiodactyls can become sound with fusion of one coffin joint on a foot
True
How can facilitated ankylosis be achieved
1) Tissue debridement, resolution of infection, cast application, and extended period of time
2) Drilling a joint
NOT doing arthrodesis - not placing implants
Claw amputation
-good restaint
-Bier block region IV anesthesia
-Ampitate point distal to fetlock/dewclaws- ideally want intercruciate ligaments attached
-Apply compression bandage to reduce hemorrhage
-Parenteral antbiotic for 7-10 days
-healing takes 4-6 weeks
animals can bear weight on the single digit for 10-20 months after which the single digit tends to develops other problems due to increased weight load it is bearing
When might digit amputation not resolve the problem
if there is significant involvement of structures common to both digits- fetlock joint, flexor tendon sheath
unlikely that amputation will resolve the problem
How do you prevent against bovine foot rot
1) Environmental hygiene- ensure proper slope and drainage of pens, scrape and remove manure
2) Adequate nutrition for hoof/skin health - zinc, copper, biotin, iodine
3) Footbaths
4) Education- early intervention, contact vet if tx fails
5) Vaccination efficacy is poor
6) Rotate pastures to minimize manure build up
7) feed cattle in elevated areas
8) minimize wet time
9) Can recur- no protective immunity
what is the number one cause of ovine lameness
ovine foot rot (OFR)
What causes ovine foot rot
Dichelobacter nodosus
-gram negative anaerobe
-up to 2 weeks survival off of the host (best in cool muddy conditions)
Is BFR or OFR contagious
OFR is contagious
How does OFR differ from BFR
OFF is contagious and caused by Dichelobacter nodosus
Dichelobacter nodosus causes
ovine foot rot (OFR)
OFR diagnosis
location, lesion, swelling and smell similar to that of BFR
painful
if caight early skin may simply be red (Scald)
then penetrates deeper through dermis and into the SQ leading to symmetrical generalized swelling of the foot, necrotic fissures, malodor, and thin greyish exudate
How do you treat OFR
1) Isolate if possible (contagious)
2) Parenteral antibiotics (7 days, longer than with BFR)
3) NSAIDs for pain
4) Cull sheep that do not respond to ABs- do not want carriers
foot trim and footbaths not wrong to do but data is not clear at present if necessary
What should you do for sheep that do not respond to OFR parenteral antibiotic tx
cull them- do not want carriers
How do you prevent OFR
1) Dont buy lame sheep
2) Consider all off-farm sheep to be coming in with isolate x 2 week minumim, footbath at least 1x week, clean and disinfect trailer
3) Watch for lame sheep and rapidly diagnose, treat, and if possible isolate
4) Vaccines not available in the US
You have a cow with both their hind legs fanned out. What digits are they lame in?
Both hind limb lateral claws
How should you pare out a sole abscess
Pare out by creating a cone-shaped channel into and surrounding the abscess pocket -
Which of the following statements correctly describes how overgrown (untrimmed) feet/claws change the distribution of the weight in the foot?
Overgrown claws shift weight bearing in a palmar/plantar direction
You have just finished herd check at your favorite dairy, when the client calls to ask you for some input on lame cows and hoof lesions. The worker who routinely trims the cows on farm has reported seeing nearly two dozen cows in the last couple of days with abscesses along the white line (white line abscesses). Based upon this information, you already have a hunch of what might be going on. With this differential in mind - which of the following things will you ask about first?
Has there been a change in the diet fed or a mixing error?
