Musculoskeletal Disease

Question 1

What is lameness?

Answer 1

• Change in pattern of gait
  
  • resulting form injury, disease, or dysfunction of 1+ limbs
• Most often due to PAIN secondary to disease
• Mechanical lameness due to abnormalities in conformation
  
  • may or may not be painful

Question 2

Where do most cases of lameness in cattle originate from?

Answer 2

• `Most often in the foot
  
  • 90% rule:
    
    • 90% of lameness originates in the foot
      
      • 90% of foot lameness in the rear foot
        
        • 90% of rear foot lameness is in the lateral claw
• Many affect the hoof capsule or interdigital space
  
  • Sole ulcers
  • White line disease ⇢ Sole abscesses
  • Footrot, hairy heel warts

Question 3

What were the risk factors for lameness in cattle?

Answer 3

• Nutritional influences
  
  • High energy diets ⇢ rumen acidosis ⇢ laminitis
• Environmental influences
  
  • Confinement
  • Concrete/rocky surface
  • wet/filthy conditions
• Genetics
  
  • Heritability of conformation
  • Abnormal hoof growth
  • Structural weakness
• Infectious agents
  
  • Footrot (infectious pododermatits, Fusobacterium necrophorum)
  • Hairy heel wart (digital dermatitis, Treponema sp)
  • Subsolar abscesses (mixed infectious agents, Trueperella pyogenes)

Question 4

What is the anatomy of the hoof capsule? (lateral view)

Answer 4

Question 5

What is the anatomy of the hoof capsule? (ventral view)

Answer 5

Question 6

Which digit bears the majority of a cows weight?

Answer 6

• Front - Medial claw
• Hind - Lateral

Question 7

What is the Sprecher Lameness scoring

Answer 7

Question 8

What is Footrot? Signs? Causes? Treatment?

Answer 8

• Interdigital necrobacillosis, Interdigital phlegmon, Interdigital pododermatitis, “foul in the foot”
• Signs:
  
  • Symmetrical swelling of the coronary band
    
    • Can extend above the fetlock
  • Erosive lesion of interdigital skin
    
    • Maceration/Injury of skin ⇢ bacteria gain entry ⇢ Necrosis
  • Necrotic smell
• Causes: Gram Negative Anaaerobe
  
  • Fusobacterium necrophorum
  • Bacteroides melaninogenicus
  • Porphyromonas spp.
  • Prevotella spp.
  • Peptostreptococcus spp
  • Dichelobacter nodosus
• Treatment:
  
  • Antibiotics
  • Debride wound +/-

Question 9

What is Hairy Heel Wart?

Answer 9

• Signs: interdigital dermatitis, painful to the touch
• Cause: Treponema spp (spirochete)
• CONTAGIOUS
• Treatment:
  
  • Oxytetracycline, Topical/Bandage
  • Footbaths

Question 10

What is the M-Score?

Answer 10

Question 11

What is the M-Score?

Answer 11

Question 12

What Questions should a Lameness exam answer?

Answer 12

• Lameness exam:
  
  • Which limb(s) are affected?
  • Locomotor scoring
  • Abnormal stance?
  • Swellings? Be precise with location and extent
  • Wounds?
  • Discharge?
  • Other information you can glean from watching an animal walk?

Question 13

What are some of the common foot lesions of cattle?

Answer 13

• Footrot (Interdigital pododermatitis)
• Hairy Heel wart (digitial dermatitis)
• Corn (interdigital fibroma)
• Abnormal growth of hoof wall/claw
  
  • Corkscrew claw
• Sole ulcer
• White line disease
• Sole abscess
• Vertical hoof crack
• heel erosion

Question 14

What is corkscrew Claw? signs? causes? treatmen?

Answer 14

• “Slipper/Scissor/Hooked claws”
• Conformational abnormality - rear lateral claws (almost always)
  
  • Inward (+/- upward) spiral of affected claw
  • Abaxial hoof wall curls under
  • Changes weight distribution
  • Changes to bony structures
  • Excessive pressure white line/sole
    
    • Sole ulcer is extremely common
• Cause: complex and not completely understood
  
  • Heritable
    
    • hereditary condition
    • Lateral claws of rear legs
    • malalignment and angulation of middle and distal phalanges
  • Obesity
  • Other pathology of the foot (abscesses/laminitis)
  • Strong individual-environmental interaction
• Treatment:
  
  • Cull
  • Frequent hoof trimming (3-4 times per year)
    
    • straighten hoof wall
    • Balance sole
    • Re-create normal weight bearing surface

Question 15

What are the basic principles of Corrective hoof trimming?

Answer 15

• Trim the dorsal toe length (7-8cm for mature bovine)
  
  • trim to just inside the white line
  • trim perpendicular to the weight-bearing surface
  • Straight line across both toes
• Trim heel to ⅔ length of the toe
• Trim sole parallel to weight bearing surface
  
  • Straight line from abaxial hoof wall to abaxial hoof wall
  • Straight line from heel to toe
• Re-create natural concavity of each toe
• Grind to finish

Question 16

What is a Sole Ulcer?

Answer 16

• Starts as bruise ⇢ pressure necrosis, becomes devitalized and leads to granulation bed at sole
• Can become septic
• Etiology: Genetics, nutrition, trauma
• Treatment:
  
  • feather edge of sole around granulation tissue
  • Wooden blocks or other lift

Question 17

What is White Line Disease?

Answer 17

• Inferior quality laminar horn that is at increased susceptibility to mechanical damage
• Separation of hoof wall from sole near the heel
• Often see gravel, stones or dirt/mud packed into separation ⇢ abscessation
• Is an indication of altered growth of horn and is often associated with laminitis

Question 18

What are Vertical Hoof Cracks?

Answer 18

• Vertical cracks in the hoof wall, more common in beef than diary animals
• Extremely dry hooves appear important
• Very long (overgrown hooves) are important
• Trauma/disruption of coronary band
• Treatment:
  
  • Shorten toe in which crack is present
  • Thin dorsal hoof wall, clean crack out down to sensitive tissue (do not disrupt corium)
  • Drain and clean out abscess material
  • Some advocate epoxy type resins
  • Re-evaluate hoof every 2-6 weeks depending upon lameness severity in animal

Question 19

What is Deep Digital Sepsis?

Answer 19

• Deep complicated infections
  
  • Chronic local lesions: sole ulcers, sole abscesses, extension of footrot
• Involves:
  
  • tendons, ligaments, bone, bursae, tendon sheaths, joint

Question 20

What conditions require surgery?

Answer 20

• Digital septic arthritis
  
  • Distal Interphalangeal Joint (DIP)
  • Proximal Interphalangeal Joint (PIP)
  • Navicular Bursa
• Tenosynovitis
  
  • Deep Digital Flexor tendon (DDF)
  • Superficial Digital Flexor Tendon (SDF)
  • DDF tendon sheath
• Pedal Otitis
• Typically all have a history of unsuccessful treatment for foot rot or sole ulcers

Question 21

What is Septic Arthritis?

Answer 21

• Most commonly affects the DIP joint
  
  • Unilateral painful swelling of coronary band
  • Draining tract: proximal aspect of coronary band, or under sole
  • Diagnosis can usually be confirmed with radiographs
  • Usually caused by extension of sole ulcer, abscess or footrot

Question 22

What is Pedal Osteitis?

Answer 22

• Septic process of distal phalanx
• Result of
  
  • extension of solar abscess
  • exposure of P3 by trauma
• Sole, infected corium, and distal phalanx are debrided until healthy, hard bone is felt

Question 23

What is Facilitated Ankylosis?

Answer 23

• Treatment indicated for deep sepsis of a digit
• Approaches
  
  • Solar
  • Bulbar (plantar)
  • Abaxial
• Depend on structures involved and location of draining tract
• Goals:
  
  • Resection of infected/necrotic bone and synovial structures
  • Adequate drainage to allow healing by second intension
  • Pain management

Question 24

What is Claw amputation? indications? Advantages/Disadvantages?

Answer 24

• Indications:
  
  • Pedal osteitis
  • Luxation or fracture of distal phalanx
  • Deep sepsis of the digit
  • Septic arthritis
• Advantages:
  
  • Rapid & Inexpensive
  • Resection of all affected tissues
  • Cattle rapidly become sound
• Disadvantages:
  
  • Reduced productive lifespan
  • Heavy animals do poorly
  • Cosmetic result is poor

Question 25

What is Tenosynovitis?

Answer 25

* Inflammation/Infection of the flexor tendons, especially within the common tendon sheath * Strongly suspect involvement if swelling extends from foot to just proximal to fetlock or dewclaw * Asymmetrically on palmar/plantar aspect just medial/lateral of long axis of limb * Can occur alone but almost always accompanies infection of another synovial structure * Can be aseptic (traumatic, idiopathic) or septic (direct extension, iatrogenic, hematogenous)