67. Causes of lameness in small ruminants (symptoms, characteristics, treatment) Flashcards
Different diagnosis of lameness Non-infectious?
Differential diagnosis of lameness
• Non-infectious
o Trauma
o Laminitis
o Trace mineral deficiency
o Soil balling between the claws
o Interdigital hyperplasia
o Toe granuloma
o Inadequate hoof trimming
o Osteoarthritis
Differential diagnosis of infectious causes?
• Infectious
o Interdigital dermatitis
o Foot rot
o Contagious ovine digital dermatitis
o White line abscess, white line degeneration
o Pedal joint abscess (septic pedal arthritis)
o Infectious polyarthritis of young lambs (joint-ill)
o E. rhusiopathiae polyarthritis in growing lambs
Name the causes of Lameness in sheep?
Interdigital hyperplasia
Toe granuloma
Foot rot
Contagious ovine dermatitis
White line abscess
Septic pedal arthritis
Infectious Polyarthritis of lambs(Joint ill)
Osteoarthritis of older sheep
Interdigital hyperplasia?
Interdigital hyperplasia
- A fold of skin grows in the interdigital space
- First insignificant, but enlarges with age
- Predisposes to further foot problems(especially interdigital dermatitis)
- May be hereditary -> should be excluded from breeding!
- Large lesions can be removed under local anaesthesia
Toe granuloma causes?
Toe granuloma
- Strawberry-like growths of granulation tissue
- Usually caused by over trimming the tip of the claw
o Profuse bleeding of the corium is followed by formation of granulation tissue
o A thin layer of horn can cover the growth later
- Most animals remain lame even if the granuloma is covered by horn
- Occasionally foreign body or chronic foot rot can also cause granuloma formation
Toe granuloma treatment and prevention and control?
Treatment:
• Careful excision with scalpel, followed by pressure bandaging for 3-5 days
Prevention/control
• Adequate hoof trimming
Interdigital dermatitis Cause?
Interdigital dermatitis (scald)
Cause:
- Wet conditions cause loss of skin integrity, allowing F. necrophorum invasion
- Restricted to the interdigital skin between the claws
Symptoms of interdigital dermatitis?
Symptoms:
- Skin seems moist
- Red/grey discoloration
- Loss of hair
- No horn separation ( foot rot)
- Though the symptoms are relatively mild, it can cause severe pain
Treatment and Prevention/Control of Interdigital dermatitis?
Treatment:
- Foot bathing
- Antibiotics (local or parenteral)
Prevention/control
- Impossible to eradicate (F. necrophorum is ubiquitous)
- Adequate hoof care of the herd will minimize prevalence
Foot Rot Cause?
Foot rot
Cause:
• D. nodosus infection, usually following a F. necrophorum invasion of the skin
o F. necrophorum causes necrosis, therefore facilitates entry of D. nodosus
o D. nodosus produces protease and elastase, damaging the deep tissues of the Foot
o There are benign and virulent strains of D. nodosus
o D. nodosus can survive in the environment for up to 1 week
Symptoms of foot rot?
Symptoms:
- Accumulation of discharge (typical, foul-smelling necrotic material)
- Separation of the sole, sometimes the whole horn capsule is shed
o Begins at the posterior part of the axial side of the horn-skin junction
- Regrowth of the horn can be abnormal
- Severe lameness
Treatment of foot rot?
Treatment
- Early detection is key
- Separation of infected animals
- Parenteral antibiotic therapy
o Penicillin-streptomycin at twice the licensed dose rate
o Long-acting oxytetracycline
o Tilmicosin
• Foot bathing
o Formalin should be avoided, as it irritates the tissues (could cause permanent damage)
o Every 2-3 days for 2-6 weeks
• Vaccination
o Limited protection for 6 months
• Therapeutic foot trimming (?)
o Removing diseased horn, only after healing commenced
Control/prevention of foot rot?
Control/prevention
- Dry pasture/bedding
- Farm biosafety
- General hygiene of the handling systems
- Vaccination
- D. nodosus is hard to eradicate, so other areas of hoof care have to improve in order to decrease
risk of infection
Contagious ovine digital dermatitis cause?
Contagious ovine digital dermatitis
Cause:
• Not fully understood; in a lot of cases, Treponema vincentii could be isolated, but it can be found
on healthy hooves as well. It’s probably caused by multiple bacteria (different strains can be
detected at different phases).
Symptoms of Contagious ovine digital dermatitis?
Symptoms:
• Detachment of the horn on one or more claws
o Starts at the coronary band of the abaxial wall ( foot rot)
o Loss of hair above the coronary band, usually not present in the interdigital space (
interdigital dermatitis)
o Severe lameness
o In severe cases, necrosis and resorption of the 3rd phalanx can occur
Treatment of contagious ovine digital dermatitis?
Treatment
- Footbaths
- Parenteral antibiotic therapy
- Bone resorption: bad prognosis
White line abscess Cause?
White line abscess
Cause:
• Defect of the white line along the abaxial wall gets contaminated, pus formation follows If the pus
is not released by trimming, it will erupt at the coronary band
Symptoms of white line abscess?
Symptoms
- Lameness without any gross lesions; diagnostic foot trimming is needed to find the lesions
- Abscesses show as a dark mark, which will release pus on further paring
- If there was a previous episode of eruption at the coronary band, a horizontal crack forms in the
wall
Treatment of white line abscess?
Treatment
- Careful paring to release the pus
- Local antibiotic treatment
Cause of Septic Pedal Arthritis?
Septic pedal arthritis
Cause:
• In some cases of interdigital infection, bacteria can spread to the distal interphalangeal joint.
Symptoms of septic pedal arthritis?
Symptoms:
- In most cases only one joint is affected
- Severe swelling, widening of the interdigital space
- One or more discharging sinuses at the coronary band (abaxially)
- Marked swelling of the drainage lymph node
Treatment of septic pedal arthritis?
Treatment
- Antibiotic therapy is useless
- Joint lavage (?)
- Amputation: good prognosis
o Adequate technique: through the 1st phalanx (not the joint)
o Adequate postoperative care: Bandage for 5-7 days, AB, NSAID, rest, clean bedding
Joint ill Cause?
Infectious polyarthritis of lambs (joint ill)
Cause:
• Arthritis following bacteraemia. Most common pathogens are Streptococcus spp. and E.
rhusiopathiae. Entry point of infection: lungs, GI system, navel.
- Lambs are infected in the neonatal period, symptoms occur at 5-10 days old
- E. rhusiopathiae: Can cause lameness at 4-6 months, usually following docking/castration, and post
dipping lameness at all ages
Joint ill symptoms?
Symptoms:
- One or more joints are affected
- Carpus>hock>fetlock>stifle joint
- Atlanto-occipital joint -> tetraparesis
