Transcript Sheep_Lameness

Sheep Lameness Diagnosis, Treatment and
Control
HOW MUCH IS LAMENESS
COSTING THE UK SHEEP
INDUSTRY?
The Cost of Lameness
• Financial losses
• Compromised welfare
• A poor image
The Cost
• With an estimated 3 million sheep lame
each year the industry is losing at least
£20,000,000 a year
How does lameness affect your
profits?
• Poorer performance
lower lambing percentage
lower growth rates
• Increased labour
• Increased vet and medicine bills
For a typical 600 ewe flock
• With a 10 %
incidence of
lameness losses
would be
around £7
per ewe or
£4200 per
year
Lameness in lambs
• Severe scald can stop lambs growing
• Twin lambs growing at 350 g/day reach 40
kg in about 14 weeks
• Scald could slow finishing by 3 or more
weeks - on a falling market this could
mean £5.00 per lamb or more
The Main Causes of Lameness
• Scald
• Foot rot
• White line disease
• Fibromas and granulomas
• Strawberry foot rot (orf)
• Laminitis
Other Causes of Lameness
• Contagious ovine digital dermatitis
(CODD)
• Post-dipping lameness
• Injury - e.g. soil balling, foreign bodies
• Arthritis – old age, joint ill
• Tick pyaemia
• Foot and Mouth Disease
Causes of lameness
4%
4% 2% 5%
2%
1%
Foot Rot
Scald
Foot Abscesses
Post Dipping Lam eness
43%
Sw ollen Joints
39%
Soil Balling
Fibrom a
Other
Foot and
Mouth
Disease
White Line Disease
Injuries - Puncture Wounds
Injuries - Soil Balling
Strawberry Foot Rot
Toe Fibroma
Contagious Ovine Digital Dermatitis
80% of lameness is due to Foot rot and Scald
4%
4% 2% 5%
2%
1%
Foot Rot
Scald
Foot Abscesses
Post Dipping Lam eness
43%
Sw ollen Joints
39%
Soil Balling
Fibrom a
Other
Scald
• Caused by Fusobacterium necrophorum
• Occurs in wet,warm
lush grazing
conditions
• Causes a dermatitis
between the claws
• Non-invasive
• Sporadic outbreaks
• Foot bathing controls
Foot Rot
Caused by
F. necrophorum AND Dichelobacter nodosus
10 strains of D.nodosus
• 7 Benign strains
• 3 Virulent strains
• Does not live on
pasture for more than
10 days
Foot Rot
Clinical signs depend on
• Strain of D. nodosus
• Genetic predisposition
• Environment / Season
Foot Rot
Treatments for Foot Rot
Paring
Foot bathing
Antibiotics
Vaccination
All treatments work best in
non-transmission periods
Foot Paring
• Inspect all feet
• Only trim if necessary
• Never draw blood!
• Use minimum cuts
• Use clean sharp tools
• Disinfect between
feet
• Destroy clippings
• Isolate infected sheep
Foot trimming
Foot Bathing
Foot bathing
• Only worth doing if under the right
conditions and according to
recommendations
• Zinc sulphate (10% solution)
• Formalin (3 % solution) - 3 pints in 12
gallons of water
• Proprietary products
Effective foot bathing
• Choose a dry day
• Run sheep through water bath to clean
feet
• Follow manufacturer’s recommendations
• Let sheep stand on dry clean surface for
up to an hour
• Turn out to fresh, dry pasture
Foot bathing
Cost of foot bathing
• 3 % formalin - 86 litre bath - £1.30
• 10 % zinc sulphate - 310 litre bath - £24
But Zinc sulphate is
1) more effective and
2) re-usable
Formalin
Pros
Cons
Cheap
Toxic
Effective
Tends to harden the hoof
Quick
Some feet missed
Not re-useable
Zinc sulphate
Pros
Cons
More effective
More time in foot bath
Re-usable
Need a larger foot bath
More pleasant
More expensive
Non irritant
Antibiotics
• Infectious disease
• Use in severe cases
• Use correct dose
• Treat before
trimming
• Check 1 week later
• Trim foot
• Cull non-responders
Vaccination
• Promotes improved
foot health
• Must continue with
routine foot care
• Timing important
• Short-term
protection
• Warning - local
reactions
Other Control Measures
• Attend to lameness cases promptly - a serious
welfare issue
• Diagnosis essential(CODD), consult veterinary
surgeon if necessary
• Cull persistently lame sheep
• Breeding - select replacements from ‘resistant’
families
• Seek veterinary advice for the best approach
• Consider eradication in ‘closed’ flocks
Foot Rot Eradication
Highly contagious - A flock problem
BUT
• D.nodosus does
not live on
pasture for more
than 10 days
THEREFORE
• Pasture not
grazed by sheep
for 10 days is
foot rot free
Foot Rot Eradication
Day 0 – Examine all of the flock.
• Footbath all sound sheep and turn out onto clean pasture
• Treat all lame sheep and segregate from main flock
Day 5 – Re-examine infected group and re-treat
Day10 – Re-examine all of the flock and footbath.
Day 15 – Re-examine infected group and re-treat
Day 25 – Re-examine all of the flock and footbath.
• Cull all chronically lame sheep in the infected group
Flock Disease Security
• Try to source foot rot free stock
• Isolate all oncoming animals for 4 weeks
• Examine every foot of every sheep
• Treat foot rot cases and keep isolated
• Mix with resident flock only when
completely free of disease
Code of Recommendations for
the Welfare of Sheep
• A written health and
welfare programme
should be prepared
for each flock
• Developed with
appropriate
veterinary and
technical advice
• Should include foot
care
• Review and update
annually