Small Ruminants: Lameness in Sheep Flashcards
Where does most lameness in sheep occur?
Most lameness in sheep is in the foot
What are the main diseases and foot lesions that cause foot lameness?
Foot rot- benign footrot, interdigital dermatitis, scald, virulent
CODD
White line disease
Toe granuloma
Foot abscess
Interdigital hyperplasia
Overgrown or misshapen claws
Foreign body
Soil balling
What non-foot diseases are associated with lameness?
Arthritis- infectious, osteo
Fractures
Muscular
Neurological
Always confirm diagnosis youself
What % of flocks are affected by benign footrot/ID/scald
97%
either on its own or part of mixed infection
flock level problem
How does benign footrot/ID/scald appear?
What is the main pathogen?
- Lame
- Interdigitsl skin inflamed ±discharge
- No horn under running (not coming off)
- Damage to skin may predispose to bacterial infection (damp, frost, thistles)
Dichelobacter nodosus- main pathogen
RWhen are outbreaks of benign footrot/scald/ID?
How can lesions progress?
Outbreaks in groups of growing lambs
Lesions can progress to footrot with underrunning of horn depending on sheep, treatment
Risk factors the same a footrot
What is footrot?
Interdigital dermatitis with
progressive under-running of sole of hoof horn starting at medial aspect of sole and progressing laterally
Grey necrostic pungent smelling horn
What are the characteristics of dichelobacter nodosus?
- Aetiological agent of foot rot
- Facultative anaerobe
- Survives 7 days in environment
- Present in normal sheep
- Virulence- fimbrae, proteases
Fusobacterium necrophorum- anaerobe, gut, faeces, often found in foot rot
What are the characteristics of dichelobacter nodosus?
- Aetiological agent of foot rot
- Facultative anaerobe
- Survives 7 days in environment
- Present in normal sheep
- Virulence- fimbrae, proteases
Fusobacterium necrophorum- anaerobe, gut, faeces, often found in foot rot
What are the risk factors associated with ID and foot rot?
- Warm
- Wet under foot conditions
- Muddy
- Housing
- Gathering
- Genetics
How is ID treated?
Topical treatment-
* oxytet spray (dry before grazing)
* Footbathing in antiseptic- formalin, zinc sulphate
Systemic antibiotics- LA oxytet
What is needed with foot-bathing for ID?
- Antiseptic needs to be exposed to inter-digital area for 2 mins approx
- Clean feet before hand
- Correct concentration
- Dry standing afterwards
How is footrot treated?
- Treat as quickly as possible
- Isolate lame sheep
- Treat individuals/groups
- Injectable LA- oxytet/amoxicillin
- May require repeat reatments
- Do not trim feet unless necessary
Should feet be trimmed before treatment?
Farmers often treat after trimming- expose air
But studies show not necessary- trimming not reccomended
What does CODD stand for?
Contagious ovine digital dermatitis
Severe lameness
How does CODD appear clinically?
Ulcerative or proliferative lesion starts at coronary band
Progressive under-running of hoofwall downwards
Hoof sloughs off
Often mixed infections
What grade of CODD is this?
Grade 1- coronary band lesion only
What grade of CODD is this?
Grade 2- <50% of horn capsule seperated
What is the difference between grade 3 and 4 CODD?
Grade 3- 50-100% hoof capsule off
Grade 4- healing but still active lesion present
What is grade 5 CODD?
Healed