Musculoskeletal - Exam 2: Worked to the Bone

What should the dorsal wall to heel ratio be for the fore claw of a cow?

2:1

What feet are generally affected by screw claw?

Rear

T/F: Screw claw is inherited and should not be used for breeding

True

Why might a bull stand with both front feet close together?

Remove weight on medial claws

What does a supporting limb lameness most commonly indicate?

Lesion in the claw

What does a swinging limb lameness most commonly indicate?

Lesion in proximal limb (joints)

What is the etiology of interdigital dermatitis?

Dichelobacter nodusus

What signalment and factors may predispose to interdigital dermatitis?

Housed dairy cattle with poor hygiene

Severe necrotic infection of the interdigital skin is called what?

Foot rot

What is the etiology of foot rot?

Fusobacterium necrophorum

T/F: Wet conditions, alkaline soils, and abrasive grounds are all factors that can predispose to foot rot

True

What is the main clinical sign of foot rot?

Sudden severe lameness

What is the etiology of hairy heel warts?

Treponema

T/F: Hairy heel warts occur more frequently in cows with increased parity

False, decreased risk with parity

T/F: Hairy heel warts is very contagious

True

What is the main clinical sign of hairy heel warts?

Lameness with heel elevation

What is an antibiotic and non-antibiotic that can treat hairy heel warts?

Tetracycline; soluble copper

T/F: The recurrence rate for hairy heel warts is low once cured

False, high recurrence rate

T/F: There is an effective vaccine for hairy heel warts

False

Laminitis affects ruminants on a diet high in what?

Carbs

T/F: Laminitis is often a herd problem

True

Acute lameness with laminitis is more common with what signalment?

Young stock

What are the five diseases associated with laminitis?

Sole ulcers

White-line disease

Toe abscess

Heel erosion

Double sole

What is the pathophysiology of sole ulcers?

Pressure on the corium from the flexor process, leading to ischemic necrosis

T/F: Corrective trimming, hoof block, and bandages are all useful ways to treat sole ulcers

False, not bandages (adds pressure, retains moisture)

Separation of fibrous connection of sole and wall is what disease?

White-line disease

What are the three sequelae of white line disease?

Localized abscess

Abscess to the coronary band

Infection of deep structures

What is the inciting event for toe abscesses?

Disruption of the hoof horn attachement

Bacterial degradation of the heel due to a moist, unhygienic environment is called what?

Slurry heel

Disturbance of the corium from nutritional or traumatic insult causes what disease?

Double sole

What is the etiology of interdigital fibroma?

Chronic irritation

When is surgical removal of interdigital fibromas necessary?

With concurrent lameness

What technique is used to achieve regional IV analgesia of the hoof?

Bier block

When is removal of the interdigital fat pad indicated?

When it is infected

What is the post-op treatment of interdigital fibroma?

Bandage with topical antibiotics and wire to limit movement

What is the etiology of fescue toxicity?

Neothyphodium coenophialum

What is the main toxin of fescue toxicity?

Vasoconstrictive alkaloids

What are the four clinical syndromes of fescue toxicity?

Dysthermia

Fat necrosis

Reproductive disorders

Fescue foot (mostly cold climates)

What is the most common cause of septic arthritis in adult cattle?

Extension from adjacent site

What is the most common cause of septic arthritis in neonates?

Hematogenous

T/F: Septic arthritis appears with acute onset of lameness

False, progressive

What are the (costly) treatments of septic arthritis if slaughter is not an option?

Facilitated ankylosis or digit amputation

What is the treatment of a non-septic fracture of the coffin bone?

Apply block to sole of adjacent claw

What is the treatment for septic coffin bone fractures?

Claw amputation

What is characteristics of a septic coffin fracture is necessary to perform claw amputation?

Must NOT involve fetlock joint and contralateral claw must be unaffected

What treatment increases the likelihood of treatment failure?

Analgesics, due to increased limb use

What is the most common fracture in calves?

Cannon bone fractures

How long should a cast be applied for a calf that is less than four weeks old?

2 weeks

How long should a cast be applied for a calve that is 1 to 3 months old?

2 - 3 weeks

How long should a cast be applied for a calf that is 3 to 6 months old?

4 weeks

How long should a cast be applied for a calf that is greater than 6 months old?

6 - 8 weeks

What are the two treatment options for fractures of the femur?

Slaughter or stall rest

What pathology is an indication for leg amputation?

Septic distal limb fractures

Osteochondrosis is associated with what predisposing factors?

Rapid growth

Grain-rich diets

High phosphorous : calcium ratio

T/F: Osteochondrosis presents with mild to moderate lameness and affects multiple joints

True

List the traumatic lesions of the stifle in progressive order of pain

Collateral ligament tears

Meniscus tears

Cruciate ligament tears

(Just collateral, a miniscule injury, and crucial damage)

What meniscal ligament tears most often?

Medial

What unique feature may indicate a meniscal tear?

Audible click when walking

What sign may be palpable with a cruciate ligament tear?

Drawer sign

Describe the stride of a cow with upward fixation of the patella

Leg locks in posterior phase, and abducts as in the anterior phase to unlock

What sign may indicate upward fixation of the patella?

Blunted toe from dragging

What is the typical cause of coxofemoral luxation?

Trauma from poor footing

What stance do cows with coxofemoral luxation have?

Toes out

How can you diagnose coxofemoral luxation?

Compare the distances from the greater trochanter to the dorsal sacrum and tuber ischii

What is the treatment of coxofemoral luxation, and what time frame must it be done in?

Closed reduction; 24 hours

What are the most common luxations of the spine?

Subluxations at lumbosacral junction

Involuntary muscle contractions involving the hind limbs is known as what?

Spastic syndrome

Progressive spastic contraction of the hindlimb is what?

Spastic paresis (Elso heel)

What are the postmortem lesions of spastic syndrome/paresis?

None

What is the etiology of slowly progressive arthritis in goats?

Caprine Arthritis Encephalitis virus (CAE)

What is the etiology of chlamydial polyarthritis?

Chlamydophila pecorum

What are the two major signs of chlamydial polyarthritis?

Polyarthritis (duh) and conjunctivitis

What signalment is most often affected by mycoplasmal polyarthritis?

Kids of dairy goats

How is mycoplasmal polyarthritis transmitted?

Milk

What is the etiology of contagious ovine digital dermatitis (infectious footrot)?

Dichelobacter nodosus

What is a characteristic sign of contagious ovine digital dermatitis?

Overgrown toes

How is contagious ovine digital dermatitis transmitted?

Through the soil

What is the prognosis of downer cow syndrome?

Guarded to grave

What is the cause of white muscle disease?

Increased need for vitamin E/Selenium, often nutrition deficiency

What are the two forms of white muscle disease and the age they affect?

Acute myocardial dystrophy (young)

Subacute skeletal dystrophy (old)

What is the pathophysiology of white muscle disease?

Lipoperoxidation of membranes (selenium/vit E are antioxidants)

What lab values would you expect to be increased with white muscle disease?

CK and AST

What is the etiology of blackleg?

Clostridium chauvoei

How is blackleg transmitted?

Through soil

How should blackleg be treated and prevented?

Penicillin and vaccination

How is malignant edema transmitted?

Through soil contaminating wounds

What environment does malignant edema prefer?

Anaerobic

What wild and domestic species are involved in the life cycle of trichinellosis?

Bears and pigs

What are the three recommendations to prevent parasitic infections?

Separate herbivores from carnivores

Remove carcasses

Don't feed raw meat

Sarcocystis has a high infection rate in what species?

Cattle, sheep, and horses

What is the toxin of cottonseed?

Gossypol

Gossypol is toxic mostly to which species?

Swine

What what percent of cottonseed in the diet presents a risk of toxicity?

10%

What is the pathophysiology of ionophore toxicity?

Disrupt normal ionic equilibrium, leading to calcium overload

What species is most affected by ionophores?

Horses

What plant common in cultivated fields can lead to diarrhea, anorexia, weakness, lethargy, hind-limb tremors, and death?

Senna

What cells are responsible for bone resorption?

Osteoclasts

What cells are responsible for osteoid and mineralization?

Osteoblasts

What cells are signaling molecules of the lacunae?

Osteocytes

What cells are stem cells for bone?

Osteoprogenitor cells