Infectious foot diseases

Question 1

What type of lesions are shown here?

Describe

Answer 1

Bovine Digital Dermatitis

• Lesions at the heel bulb, above the coronet band
• ++Pain and lameness

Question 2

What possible problems are caused by prevalence of BDD in a herd?

Answer 2

• Major cause of lameness: welfare issue
• Milk drop
• Reduced VFI
• Treatment – efficacy, costs, environment, milk discard
• Increased culling rate
• Increased labour costs

Question 3

What aetiological agents cause BDD?

Which is most commonly identified?

Answer 3

1. Fusobacteria
2. Dichelobacter
3. Campylobacter
4. Mycoplasma
5. Spirochetes
6. Treponemes (secondary to spirochetes)

Question 4

What stain is used to characterise spirochetes from BDD lesions?

Answer 4

Silver nitrate

Question 5

Treponemes are often involved in co-infection with spirochetes.

Name the species commonly involved.

Answer 5

medium, phagedenis, denticola-like

Question 6

Outline a treatment/ control plan for BDD.

Answer 6

• Footbaths
  
  • Chemical (widely used): Formalin/copper sulphate
  • Antibiotic (less used) e.g. Lincospectin
• Topical treatments
  
  • Tetracycline (blue) spray
  • penicillin (systemic) or macrolides (systemic/oral) likely better
• Recurrence is common/normal
• Regular foot trimming

Question 7

In which condition is lameness more severe BDD or CODD?

Answer 7

CODD

Question 8

What sources of BDD and CODD have been identified on farm?

Answer 8

Ruminant GI tract

Slurry

Direct contact and

Foot trimming equipment

Question 9

How can CODD be controlled in a herd?

Answer 9

• Regular fotobaths
• Biosecurity - isolate bought on for 30d
• Vaccines? None currently avaliable
• Ab’s

Question 10

What lesion is characterised in this picture?

Describe

Answer 10

CODD

• Severe lameness
• Loss of horn capsule
• Pain +++

Question 11

What type of lesions are shown here?

Describe

Answer 11

Ovine footrot

• Lameness
• Wt loss
• Interdigital dermatitis
• Interdigital hoof wall lesions
• Separation of hoof from tissue

Question 12

Which aetiological agent has been shown to cause ovine footrot?

What virulence factors are utilised by the bacteria?

Answer 12

Dichelobacter nodosus

• Extracellular proteases
• Fimbrae for motility and attachment - highly immunogenic

Question 13

How are D nodosus serotyped?

Answer 13

Using the serotypes of fimbrae proteins

Question 14

How is ovine footrot transmitted between sheep?

What is the survivability of the bacteria in the environment like?

Answer 14

Direct/ indirect

Poor

Question 15

How can ovine footrot be treated and controlled?

Answer 15

• Foot trimming
• Topical disinfectants/ antibiotics
  
  • formalin
  • sulphate/ oxytet
  • Systemic penicillin/ streptomycin
• Vaccine - fimbril proteins

Question 16

Which aetiological agents has been idetified as causing ovine interdigital dermatitis?

Answer 16

Dichelobacter nodosus

Question 17

Scald

Answer 17

Ovine interdigital dermatitis

Question 18

What clinical signs characterise Scald?

Answer 18

• Red/ pink inflammation of the interdigital space
• Grey scum present
• Painful
• Lameness

Question 19

Foul in the foot

Answer 19

Interdigital necrobacilliosis

ie bovine footrot

Question 20

Which aetiological agents have been identified in causing FITF?

Answer 20

• Fusobacterium necrophorum
• Bacteriodes melaninogenicus

Question 21

What clinical signs characterise Foul in the Foot?

Answer 21

• Severe lameness
• Holds leg in the air (++ pain)
• Interdigital space swelling
• Fever
• Anorexia
• Decreased milk yield

Question 22

How can FitF be treated/ controlled?

Answer 22

• Footbathing
• 3d systemic Ab - penicillin/ oxytet/ macrolide
• Control environmental reservoir/ manure