Food Ani. Med- Bovine- Musculoskeletal Disorders (Lameness) 2

wilsbach's version from 2016-03-18 22:47

Laminitis (Founder) / Pododermatitis circumscripta (Rusterholz Ulcer) / Sole Ulceration

Question Answer
what is laminitis?Inflammation of the sensitive lamina (Corium) of the foot. Corium= Germinal Centers for growth of claw (horn).
explain the pathogenesis of laminitisDisturbance of the micro-circulation within the corium --> Breakdown of the dermal/epidermal junction between the hoof wall & P3.
what is a MAJOR predisposing factor to laminitis in rumis?Rumen Acidosis is a major predisposing factor. also SARA= Sub Acute Rumen Acidosis
explain how rumen acidosis--> lamnitis/P3 rotation Release of vasoactive substances --> Increased Blood flow, Thrombosis, Ischemia, Hypoxia, and Arteriole / Venus Shunting --> Edema / Swelling, Bleeding, and Necrosis of the corium tissue. SO THEN.... Inflammation within the hoof --> Increased pressure, Pain, and Tissue damage. SO THEN... Damage to the dermal / epidermal junction --> Sinking of P3 --> Sets the stage for sole ulceration and the rotation of P3 within the hoof
laminitis is often noted as... (Cs you might see)Noted as swelling of the coronary band.
a rusterholz ulcer is the primary cause of lameness in which cattle?dairy
What is his ulcer caused by?Caused by inferior sole growth over the attachment of the DEEP DIGITAL FLEXOR TENDON. (said in class:) as they wear heel down, they ride back, toes grow faster. but when ride back, put weight where it shouldn't normally be-- near DDFT (bleeding spot on pic)
what are 2 problems a RU can lead to? Can lead to tenosynovitis or osteomyelitis (makes sense bc Caused by inferior sole growth over the attachment of the DEEP DIGITAL FLEXOR TENDON.)
(said in class) what do you do about/how do you treat a RU?You will need to remove all of the tissue including granulation tissue until you reach the fresh tissue which is connected to underlying tissue. This is bc if you leave spot not attached to underneath tissue (flap or pocket left) it will not heal-- will maintain that pocket.
what is a sole ulcer?Circumscribed loss of horny sole that exposes the corium
what causes a sole ulcer?Sole ulcers are caused by added pressure to the area. (said in class: so puts weight in an are where it isn't supposed to carry that weight. bruise and hge. not infection-- can get 2* infxn tho. So take piece of hoof out (remove all discolored hoof etc) )
explain how early and mature sole ulcers differ by appearanceEarly ulcers are circumscribed areas of fresh tissue that is uncovered by trimming. Mature ulcers are usually covered by rough and irregular horn tissue. When trimmed---> Uncover fresh granulation tissue that bleeds easily
how do you treat a sole ulcer? Trim unaffected claw to restore proper confirmation. Removal of the necrotic horn tissue followed by elevation of the affected claw.
how can you prevent sole ulcers? Regular foot trimming to maintain proper balance and weight bearing to the feet.

White Line Disease / Toe Abscess / Corkscrew Claw

Question Answer
what is the white line? Weight bearing area of the claw. Active area of claw formation. (circled in red-- area 1)
where is the active area of claw formation?WHITE LINE!
where is the site of hge during acute laminitis? Site of hemorrhage during acute laminitis. Sites of hemorrhage become visible as the sole grows making a useful indicator of subclinical acidosis. It is a highly vascular area
white line dz= what problem?subsolar abscess
white line dz causes ACUTE LAMENESS due to what underlying problem?metabolic acidosis
explain the pathogenesis of WLD and how it leads to distorted claw growthDiseased corium --> Soft hoof horn prone to separation --> Increased wear & penetration by foreign material. Widening of the white line caused by dermal-epidermal separation --> distorted claw growth.
how do you treat WLD?Paring & drainage of the affected area: Create a drain through the original site, which is Found as a discolored area that is packed with debris. Then Pare away hoof material adjacent to the abscess. This Decreases weight bearing and Prevents material from repacking the tract. You can consider (+/-) a hoof block. Antimicrobials are rarely required.
best way to prevent WLD is to prevent...laminits
which population of cattle are toe abscesses most common in?Most common in feeder cattle entering yard. More common in wild cattle.
**toe abscesses most commonly happen in.... front or rear? M or L?Occurs more commonly in the lateral claw of the hind feet.
what are toe abscesses caused by? How can you ID this problem? Caused by trauma to the toe of the soft claw-- ID by a rounding of the toe.
(said in class) which is worse-- finely ground feed or lots of simple sugars?about the same horribleness- if its finely ground the bact have more access to it
what are clinical signs of toe abscesses like? (early and then progression)Early signs are subtle: Cattle appear to short step, no swelling. If you treat early they can recover. As it progresses, you might see the animal start to stand on 3 legs. Once it is chronic, you might see swelling at the coronary band. If you press on the toe, it will feel soft, and a crack might be noticed.
how do you treat toe abscesses?Relieve pressure by trimming the tip of the toe. If it bleeds, you took too much.
what is corkscrew claw? how do they get this problem?Inherited condition where the claw starts to grow in a twisted fashion.
*which claw is most commonly affected by corkscrew claw? Rear lateral claw most common
what age do you start to see corkscrew claw? Manifests late – 3 years old
what parts of the foot can be affected by corkscrew claw? P3, claw capsule, connective tissue
how do you tx corkscrew claw?Treatment: corrective trimming
ddx for corkscrew claw?laminitic lesions

Sand Crack / corns / Horizontal Grooves

Question Answer
is a sand crack a vertical or horizontal crack?vertical
are sand cracks more common in beef or dairy?More common in beef cattle; Unknown cause
severity of sand crack depends on..Severity of disease depend on amount of separation of crack
how do you tx sand crack?(vertical crack) Clean out crack. Check for underlying abscess. If separation of margins, can use polymethylmethacrylate or wires to hold together.
what are "corns" ?Interdigital Fibroma
what is happening in corns/interdigital fibromas?Thickening of interdigital skin & Sub Q tissue.
where are corns most common-- and what factors can this vary with? Front Feet of Bulls VERSUS Rear Feet of Cows
do you need to tx corns? how do you tx?No treatment necessary unless it is causing lameness (like its growing below the hoof so theyre walking on it) Surgically remove for tx
wut dis? corns (interdigital fibroma)
when do horizontal grooves happen? Usually occur during time of stress or sudden nutritional change (consider talking to them about feeding practices- might mean acidosis. )
do horizontal grooves cause lameness? No lameness with simple grooves, but Deep grooves may cause distal toe to break off
how do you tx horizontal grooves?Trim feet, monitor nutrition

Hoof trimming

Question Answer
hoof grows how much a month? (prolly not important but on slide)5mm
overgrowth of hoof leads to..overloading of claws
overgrowth leading to overloading of claws is more pronounced on which claws of the hind feet, and which of the front?lateral claw hind and medial claw front.
overgrowth leading to overloading of claws is more pronounced on which part of the hoof? explain. More significant in the toe. Claw is harder & there is less wear, and Heel is softer, has slower growth --> Increased ware. Both lead to lengthening and raising of the toe.
The angle of the dorsal surface (front of hoof) should be?45* (DONT WANT IT LOWER THAN THAT)
overgrowth of the toe will be greater if there are what 2 factors at play?Overgrowth will be greater if the animal has experienced laminitis or is housed on concrete.
how often/when do you do hoof trimming?1 – 2 times a year, usually at Dry Off and Mid-lactation ( Most operations only trim at dry off.)
Objective for Preventive Foot Trimming (3)(1) Restoration of proper balance & weight bearing on each claw. (2) Hoof overgrowth is the most significant problem ( Lateral claw of the rear foot. Medial claw of front foot) (3) Correction of lesions at an early stage.
(said in clasS) how can you determine the length the toe should be?lay hand sideways over dorsum with top of hand touching -- where your hands end should be where they are
Step #1 is Judge the length of the claws-- in the hind legs, which claw is considered more "normal" and used as a model for the other claw? Medial hind claw= More normal claw & is used as a model for the lateral claw. (the lateral hind is where all the probs are, so judge based on the other one lol)
the front wall of the claw should be how long?3 inches
how thick should the sole be?Sole should be a minimum of a 1/4 inch.
Spare as much of the heel on the ____ (M or L?) claw as possible medial
pic explaining how overgrowth affects pressure distribution in foot
always start by trimming which claw of the rear foot?medial
list the 6 basic steps of hoof trimming(1) Judge the length of the claws (+trim medial claw of hind foot) (2) Trim the lateral claw of the hind foot (3) Shape & Slope the sole. (4) Balance the heels (5+6) Therapeutic & Corrective
how do you trim the dorsal wall/toe? Sole? heel?Reduce dorsal wall of the medial claw (in rear do medial first) to 3” but trimming the toe at 90* to the sole. Then trim the sole and wall to flatten. DO NOT trim the heel unless absolutely necessary. The sole & toe should be solid-- Applying pressure should not deform the sole.
When finished the weight bearing surfaces should be flat at _the toe
which part of the sole and where should you slope the sole towards? Slope the innermost back portion of the sole toward midline (Avoid excessive cupping or sloping).
why do we slope the sole/ what does a proper slope allow? Proper slope --> Decreased pressure at the site of sole ulceration. Should also open the interdigital space.
Weight bearing surfaces should be flat at the -- (3 places)toes, walls, & heels.
if there is a dzs claw, where do you want to inc weight bearing?on the healthy claw. Lowering the damaged or injured claw --> Decreased wt. bearing & allows recovery. A hoof block may be placed to further reduce load on the damaged claw.