Production animal lameness 3 - PORCINE AND OVINE Flashcards
Aetiology - porcine arthritis
- rarer in outdoor pigs
- sporadic opportunist infection in individuals (E.coli, Staphs, Streps) through wounds
- Group outbreaks (Strep suis type 14 - via tonsils)
Presentation - arthritis in piglets
- 2d weaning
- can’t stand, dog sitting
- enlarged joints
- death, starved, lai dupon
- may have meningitis CS
Dx - arthritis in piglets
Bacteriology - from discharge or PME
Tx - arthritis in iglets
- Lincomycin
- penicillin
- ampicillin
- ketoprogen
- euthanasia (if no respnse)
- all ABs above are licensed
Causes - lameness in growers
- injury, fractures
- osteochondrosis dessicans
- patothenic acid def (rare)
- ionophore toxiticity (rare)
- infectious: Mycoplasma hyosynoviae, Mycoplasma hypopnuemoniae or Hyorrhinis polyarthritis (and pneumonia), Erysipelas (zoonosis, skin lesions)
Dx - lameness in growers
- hx
- PE
- PM
- paired serology
Tx - lameness in gorwers
Infectious causes: tiamulin, lincomysin, tylosin
What % of sow culls are d/t lameness?
30%
Types of lameness in adults
- Physical
- infectious
- Septic laminitis
Outline physical lameness in adult pigs
- Cartilaginous pathlogy (osteochondrosis, osteochondritis, dyschondroplasia, or DJD)
- bony pathology –> weakness and fracture (osteomalacia)
Outline infectious arthritis in adult pigs
- Erysipelas
- Mycoplasma sp
What is septic laminitis in adult pigs?
= ‘bush foot’ d/t bacterial infection. treat with lincomycin and NSAIDs. Similar to white line abscess in cattle.
What are the 6 main lesions causing lamenes in sheep?
- scald/ strip
- footrot
- Contagious ovine digital dermaititis (CODD)
- shelly hoof
- toe granuloma
- abscess
What is CODD?
= Contagious Ovine Digital Dermatitis
- similar to DD in cattle
How many sheep are lame?
10% UK flock
What is scald caused by?
primarily caused by Fusobacterium necrophorum which is in faeces i.e. ubiquitus and usually Dichelobacter nodosus
What is essential to cause footrot?
Dichelobacter nodosus
What causes CODD?
The same treponemes (bacteria) that cause bovine DD
Aetiology - shelly hoof and toe abscess
Poorly understood
Aetiology - toe granuloma
Largely caused by farmers and vets (overtrimming)
Footrot - control
- manage footrot and scald as one disease
- most important: early action, PN ABs and topical spray, NO trimming
- if possible, separate sheep lame with footrot or scald
Outline routine foot trimming for sheep
- probably unnecessary on many farms
- shouldn’t be art of footrot control programme
- can lead to permanent damage to the shape of the foot
- even sheep with overgrown feet don’t need foot trimming unless it is affecting their ability to walk
What determines whether scald will progress to footrot?
- whether D. nodosus is on the farm
- virulence and dose of D. nodosus
- sheep susceptibility
- whether sheep are tx promptly before separation of hoof horn occurs
Describe D. nodosus
- present on >90% sheep farms
- lives for 7-10d on pasture (warm, moist)
- lives up to 6 wks in hoof clippings
- main reservoir = infected sheep
Outline approach to a group of sheep with some lame
- watch 2x week
- trim just enough for diagnosis
- dispose of clippings
- treat
- record (for culling/selection)
Tx - footrot
- OTC spray (clean foot)
- Long-acting PN AB (OTC or amoxicillin)
- allow sheep to stand on clean concrete
- clean up area
- ideally isolate sheep for 14d
Prognosis - footrot
- 90% recover in 5d
- if recovered after 14d, return to flock
- in not then retreat
Tx - scald (ewes, lambs, group outbreaks)
- ewes - as footrot
- lambs (OTC spray, stand in clean area, re-spray in 5d if necessary)
- group outbreaks: footbath, turnout to clean field, re-treat sheep still lame after 5d
Presentation - scald - 2
- pale white skin
- characteristic smell
When should you cull lame sheep?
- if still lame after 2 AB tx
- if 2 episodes of lameness
- if mishaped claws
What chemicals are used for footbathing?
- 10% ZnSo4
- 3% formalin (most common)
- NOT CuSO4 (risk of toxicity if sheep drink it)
Method - footbathing
- stand sheep in Zn for > 2 minutes
- stand sheep for 1 hour after
- turn into a field rested for >15 d
What is footvax?
= vaccine containing inactivated Bacteroides nodosus
- vaccinate before high risk periods (usually Autumn/ Spring)
- primary = twice, 6 wks apart
- boost 6 monthly (could use every 4-5 months)
- include all sheep (incl. rams)
- CARE: risk of self-injection (MAY loose finger)
Tx - CODD
- Tilmicosin (Micotil) = a macrolide AB
- vet administration only
- footbath with lincomycin (lincosamide) or tylosin (macrolide) (only instance to use AB footbath)
