Ruminant infectious foot diseases

Question 1

What does foot and mouth disease affect?

Answer 1

Cloven hoofed animals

Question 2

Why is bovine digital dermatitis a economic problem?

Answer 2

Causes reduction in milk yield + reproduction

Question 3

Where are digital dermatitis lesions located?

Answer 3

above coronet between heel bulbs

Question 4

What bacteria are present in digital dermatitis lesions?

Answer 4

Fusobacteria
Dichelobacter
Campylobacter
Mycoplasma
Spirochaetes

Question 5

What staining of skin biopsies is used to identify spiral organisms?

Answer 5

Silver nitrate

Question 6

What is always seen in BDD lesions that is not seen in normal skin?

Answer 6

Spirochaetes

Question 7

What are the 3 treponmes?
What are these in humans?

Answer 7

*Treponema medium - human periodontal spirochete
*Treponema phagedenis - human commensal of genital urinary tract
*Treponema denticola - human periodontal spirochete

Question 8

What is the aetiological agent of BDD?

Answer 8

Treponemes

Question 9

What gram is BDD bacteria?

Answer 9

Gram negative

Question 10

How is digital dermatitis diganosed?

Answer 10

Usually visual - lameness + lesion score

Question 11

How is digital dermatitis treated?

Answer 11

*footbaths - formalin (chemical) / lincospectin (antibiotic)
*topical tx - Tetracycline spray
-Penicillin / macrolides

Question 12

When are BDD outbreaks highest?

Answer 12

Winter (housing) months

Question 13

What are infection resevoirs for BDD?

Answer 13

*Ruminant GI
*Slurry
*Direct contact
*Foot trimming equipment

Question 14

How is BDD controlled?

Answer 14

*Regular footbathing
*Improve biosecurity + hygiene

Question 15

How is CODD diagnosed?

Answer 15

*Visual - lameness + lesion score

Question 16

What is the treatment of CODD?

Answer 16

*Footbaths - formalin (chemical)
-Lincospectin (antibiotic)
*Topical treatments - Tetracycline spray
*amoxicillin/penicillin or macrolides (systemic)

Question 17

What are risk factors for CODD?

Answer 17

*Dairy cattle in close proximity
*Foot rot
*Ruminant GI
*Direct contact
*Foot trimming equipment

Question 18

How is CODD controlled?

Answer 18

*Regular footbathing
*Improve hygiene + biosecurity
*Individual systemic LA amoxicillin tx
*Isolate lame sheep

Question 19

What does ovine footrot begin as?

Answer 19

Interdigital dermatitis

Question 20

What is the primary agent of ovine footrot?

Answer 20

Dichelobacter nodosus - gram negative anaerobe

Question 21

What are the virulence factors of dichelobacter nodosus?

Answer 21

*produce extracellular proteases
*Has fimbriae = motility + adherence
*Fimbrial proteins = highly immunogenic

Question 22

What climates do footrot like?

Answer 22

Mild climate with abundant rainfall (UK)

Question 23

What is another gram negative anaerobe found in footrot lesions?

Answer 23

Fusobacterium necrophorum

Question 24

How is footrot diagnosed?

Answer 24

Clinical signs

Question 25

How is footrot treated?

Answer 25

*formalin + zinc sulfate footbaths *Topical disinfectants + antibiotics

Question 26

How is footrot controlled?

Answer 26

 Footbathing, Foot trimming  - antibiotic injections LA amoxicillin  - vaccination: based on fimbrial proteins e.g. 8-10 serogroups  - biosecurity, isolation & selection for resistance (culling)

Question 27

What is the colloquial term for ovine interdigital dermatitis?

Answer 27

Scald

Question 28

What does scald look like?

Answer 28

 Red/pink inflammation of skin between claws with white/grey pasty ‘scum’ on top.

Question 29

What bacteria is found in scald lesions?

Answer 29

Dichelobacter nodosus

Question 30

What is the treatment + control of scald?

Answer 30

Same as footrot

Question 31

What is the treatment + control of scald?

Answer 31

Same as footrot

Question 32

What is bovine foul in the foot?

Answer 32

bovine interdigital phlegmon

Question 33

What bacteria are in bovine foul in the foot?

Answer 33

*Fusobacterium necrophorum *Bacteriodes melaninogenicus

Question 34

What is the clinical signs of foul in the foot?

Answer 34

*Severe lameness *Animal holds leg in the air to relieve pressure *Swelling of interdigital space *Fever *Anorexia *reduced milk yield

Question 35

What is the treatment of foul in the foot?

Answer 35

3 day systemic penicillin, oxytet / macrolide TOPICAL NOT EFFECTIVE

Question 36

What is the control of foul in the foot?

Answer 36

Footbathing with disinfectants

Question 37

What is an infection reservoir of foul in the foot?

Answer 37

Environment + manure