Impacts (9)
- Eat less
- Thinner
- Less growth
- Less wool
- Fewer live lambs
- Less milk
- Less production
- More other disease
- More management time and cost
Interdigital dermatitis (Scald)
- Dichelobacter nodosus (+fusobacterium necrophorum)
- warm, wet feet (muddy areas, lush grass, high stocking density)
- possible initial stage of foot rot
- no four smell or underrunning of horn
- Tx: oxytetracycline blue spray/ foot bathing
Foot rot
- agent
- pathogenesis
- incidence
- CS (3)
- Tx (2)
- Dichelobacter nodosus (+fusobacterium necrophorum)
- starts at interdigital space, horn becomes underrun and then it affect the sole of foot
- Persists in environment for 10-14days (6 weeks in horn trimming)
- incidence varies with: rainfall, temperature, stocking density, genetics, flock turnover
CS:
- very lame/recumbant
- very sore
- may carry affected leg/ walk on carpi if both feet are affected
Tx: systemic, long acting ABs/cull: must be treated within 3 days of being lame
Footrot
- Pathogenesis (5)
- Consequence
-swelling and moistoning of interdigital space –> break occurs at junction between skin-horn junction –> infection spreads under the horn tissue –> hoof becomes separated and the sole underrun –> characteristic foul smelling discharge
hood wall becomes over grown and misshapen –> traps dirt and inflammatory exudate between inflamed, granulating ST of sole and overgrown horn –> feet become flystuck
Contagious ovine digital dermatitis (CODD)
- Facts (5)
- Tx (3)
- Footbaths (4)
- very painful
- caused by treponemes
- initial lesion at coronary band
- rapid spread, seperates hoof
- whole hood loose and may slough
Tx:
- injection with macrolides, tetracyclines or amoxicillin
- AB foot bat
- NSAIDs
Footbath:
- 2.5-5 % formalin (carcinogenic)
- 10% zinc sulphate
- Copper sulphate (copper can kill sheep)
- ABs not licensed
Erysipelas
- types
- agent
- CS (4)
- Dx
- Tx
- Px
- chronic arthritis in young lambs (from sucking off mothers) and post dipping/muddy pens
- infective arthritis
- erysipelothrix rhusiopathiae (present in soil/stale dip)
CS:
- severe lameness
- hock and carpal joints
- heat and pain
- proliferative synovitis
Dx: joint aspirate smear and culture/PM
Tx: penicillin & NSAIDs
Px: Dip management and vaccination
Tick Pyaemia
- Facts (4)
- Px
- Tx
- staph aureus
- predisposed by tick borne fecer
- acute and chronic forms
- young lambs
Px: spot non pyrethroids prior to tick exposure
Tx: ABs for infection and NSAIDs for comfort
White line disease (5)
- most common
- defect in lamellae between hoof and the foot itself
- hood separates from lamellae
- dirt impacts can result in abscess
Tx: foot trimming!
Abscess (2)
- Trim foot and drain
- ABs can speed recovery
Granulomas (3)
- secondary to overtrimming
- associated with formalin footbaths
- can be cauterised
Interdigital Fibromas (2)
- Skin fold rubs between the cleats and become sore
- Cauterise or excise (bandage if excise to prevent infection)
Control of lameness (6)
- Footbathing
- ABs
- Biosecurity
- vaccination
- Foot trimming
- Culling
