Farm Animal Lameness Pigs and Sheep Flashcards
Aetiology of arthritis in piglets?
- rarer outdoors
> individual infections: sporadic opportunist infection (E. COli, Staph and strep) through wounds (tail, teeth, skin, navel)
> group outbreaks: Strep suis type 14 via tonsils
Presentation of arthritis in piglets
2d - weanling
- cant stand, dog sitting
- enlarged joints
- death (starved/laid on)
Dx of arthritis in piglets
- bacteriology
- discharge from wounds or PM samples
Tx arthritis in piglets
- lincomycin
- penicillin
- ampicillin
- ketoprofen
- euthanasia if no response
Lameness causes in growers
- injury (fx)
- osteochondrosis dessicans
- pantothenic acid deficiency (rare)
- ionophore toxicity (rare)
> infectious - mycoplasma hyosynoviae
- mycoplasma hyopneumonia or hyorhinis polyarthritis (and pneumonia)
- erisypelas (zoonotic: note skin lesions)
Dx cause of lameness in growers
- hx
- PE
- PM
- paired serology
Tx for infectious lameness in growers
- tiamulin
- lincomycin
- tylosin
What proportion of sows are culled d/t lameness?
30%
Main causes of lameness in sows?
> physical lamenss - cartilaginous pathology (osteochondrosis, osteochondritis, dyschondroplasia, degenerative joint disease (DJD)) - bony pathology -> weakness and fracture (osteomalacia) > infectious - erysipelas - mycoplasma spp. > septic laminits -"bush foot" d/t bacterial infection - tx: lincomycin and NSAIDs
How can lameness causes be identified in adult sows?
> inspect foot
- NAD on PE?
- visable abnormalities, pig off food / febrile, swellings?
sudden or chronic onset?
Causes of sudden onset lameness in sows with NAD on PE. Most likely? *
- acute leg weakness OCD*
- back muscle necorisis
- broken back
- calcium phosphorus deficiency
- Fx*
- laminitis
- muscle tear
- muscular dystrophy
- trauma *
Causes of chronic onset lameness in sows with NAD on PE. Most likely? *
- abscesses
- erisypela*
- myscoplasma arthritis*
- leg weakness OCD*
- rickets
Causes of sudden onset lameness in sows with abnormalities on PE (swelling/fever/off food). Most likely? *
- back muscle necrosis
- erisypelis *
- fx
- haematoma
- PSS
- streptococcal infecton *
- vascular dz
Causes of chronic onset lameness in sows with abnormalities on PE (swelling/fever/off food). Most likely? *
- bursitis
- bush foot*
- erysipelas*
- Glassers disease*
- Mycoplasma arthritis*
- Vascular disease
6 lesions causing sheep lameness
> scald (70%) = interdigital dermatitis - red, wet interdigital space, +- white grey scum, loss of hair > foot rot (30%) - separation of horn from live tissue, starts between claws, foul smell, grey oozing puss > CODD (25%) = contagious ovine digital dermatitis - loss of hair above coronary band, separation of hoof and coronet, blood + grey scum, not smelly, hoof can detach completely > shelly hoof (10%) = white line degeneration - some separation of horn from wall - pocket impacted with soil - half moon appearance > foot abscess (10%) - sheep v lame - swelling of skin/pus above coroncary band - separation of white line/penetration with stone/thorn may be vis > toe granuloma (10%) - strawberry like growth @ toe - sometimes hidden by overgrown horn - bleeds when handled
What % of the UK flock is affected by lameness?
10%
What pathogen causes scald? Foot rot?
- Fusobacterium necrophorum (in feaces, ubitquitous)
- usually also Dichelobacter nodosus (required for ‘foot rot’)
What pathogen causes CODD?
Treponemes
Pathogenesis of shelly hoof and toe abscess?
Poorly understoof
Cause of toe granuloma?
Farmers and vets!!
Footrot control?
- manage and tx footrot and scald as one disease
- most important: early Tx with parenteral Abx + topical spray
- NO foot trimming
- separate affected sheep out
Is routine foot trimming usually necessary?
- probably not many farm
- should NOT be part of footrot control
- can -> permenenant damage to shape of foot
- unless affected ability to walk, even seemingly ‘overgrown’ feet do not need trimming
What is the risk of scald progressing to foot rot dependant on?
- D. nodosus present on farm?
- virulence and dose of D. nodosus
- susceptibility of sheep
- Prompt tx before separation of the hoof horn?
Is Dichelobacter nodosus commonly present on farm?
Yes >90% UK sheep farms
What conditions does Dichelobacter nodosus thrive in? How long can it survive on pasture?
- warm moist conditions
- 7-10d on pasture
- 6 weeks in hoof clippings
Main reservoir of D. nodosus?
Infected sheep
Outline the approach to a group with some lame sheep
- watch group walking 2x weekly
- trim just enough for dx
- DISPOSE of clippings
- tx
- record for culling/breeding selection
Tx of footrot
- oxytet spray (clean foot first)
- long acting parenteral ABx (oxytet, amoxicillin)
- allow sheep to stand on clean concrete
- clean up after!!!!
- ideally isolate sheep for 14d
Prog footrot?
90% recover in 5d
- if recovered by 2 weeks return to flock, otherwise keep separate and continue treating
Tx of scald? Ewes and lambs?
- ewes = footroot
- lambs: oxytet spray, stand in clean area, respray q5d if necessary
Tx of group outbreaks of scald?
- footbath
- turnout into clean field
- re-tx sheep still lame after 5d
> cull IF - still lame after 2 Abx tx
- 2 episodes of lamenss
- misshapen claws
What footbaths are available for tx of scald in sheep?
> 10% ZnSO4 > 3% formalin * NOT CuSO4 - stand for >2mins - stand for 1hr post dip - turn into a field rested for >14d
What preventative tx is available for scald?
> footvax
- vax before high risk periods (autumn/spring)
- 1* course: 2x 6 weeks apart
- boost q6months (could use every 4-5months)
- include ALL Sheep inc rams
- care risk of self injection -> severe pain and swelling*
What equivalent disease in sheep causes bovine digital dermatitis? What pathogen?
CODD (contagious ovine digital dermatitis)
- treponemes
Tx treponemes CODD?
- Tilmicosin (micotil, vet only)
- Footbath with lincomycin or tylosin
5 main points for treating lameness in sheep?
- check twice weekly
- tx scald/footrot with Abx
- avoid trimming
- cull repeat offenders
- Vaxx
