Ruminant infectious foot diseases Flashcards
What does foot and mouth disease affect?
Cloven hoofed animals
Why is bovine digital dermatitis a economic problem?
Causes reduction in milk yield + reproduction
Where are digital dermatitis lesions located?
above coronet between heel bulbs
What bacteria are present in digital dermatitis lesions?
Fusobacteria
Dichelobacter
Campylobacter
Mycoplasma
Spirochaetes
What staining of skin biopsies is used to identify spiral organisms?
Silver nitrate
What is always seen in BDD lesions that is not seen in normal skin?
Spirochaetes
What are the 3 treponmes?
What are these in humans?
*Treponema medium - human periodontal spirochete
*Treponema phagedenis - human commensal of genital urinary tract
*Treponema denticola - human periodontal spirochete
What is the aetiological agent of BDD?
Treponemes
What gram is BDD bacteria?
Gram negative
How is digital dermatitis diganosed?
Usually visual - lameness + lesion score
How is digital dermatitis treated?
*footbaths - formalin (chemical) / lincospectin (antibiotic)
*topical tx - Tetracycline spray
-Penicillin / macrolides
When are BDD outbreaks highest?
Winter (housing) months
What are infection resevoirs for BDD?
*Ruminant GI
*Slurry
*Direct contact
*Foot trimming equipment
How is BDD controlled?
*Regular footbathing
*Improve biosecurity + hygiene
How is CODD diagnosed?
*Visual - lameness + lesion score
What is the treatment of CODD?
*Footbaths - formalin (chemical)
-Lincospectin (antibiotic)
*Topical treatments - Tetracycline spray
*amoxicillin/penicillin or macrolides (systemic)
What are risk factors for CODD?
*Dairy cattle in close proximity
*Foot rot
*Ruminant GI
*Direct contact
*Foot trimming equipment
How is CODD controlled?
*Regular footbathing
*Improve hygiene + biosecurity
*Individual systemic LA amoxicillin tx
*Isolate lame sheep
What does ovine footrot begin as?
Interdigital dermatitis
What is the primary agent of ovine footrot?
Dichelobacter nodosus - gram negative anaerobe
What are the virulence factors of dichelobacter nodosus?
*produce extracellular proteases
*Has fimbriae = motility + adherence
*Fimbrial proteins = highly immunogenic
What climates do footrot like?
Mild climate with abundant rainfall (UK)
What is another gram negative anaerobe found in footrot lesions?
Fusobacterium necrophorum
How is footrot diagnosed?
Clinical signs
How is footrot treated?
*formalin + zinc sulfate footbaths
*Topical disinfectants + antibiotics
How is footrot controlled?
Footbathing, Foot trimming
- antibiotic injections LA amoxicillin
- vaccination: based on fimbrial proteins e.g. 8-10 serogroups
- biosecurity, isolation & selection for resistance (culling)
What is the colloquial term for ovine interdigital dermatitis?
Scald
What does scald look like?
Red/pink inflammation of skin between claws with white/grey pasty ‘scum’ on top.
What bacteria is found in scald lesions?
Dichelobacter nodosus
What is the treatment + control of scald?
Same as footrot
What is the treatment + control of scald?
Same as footrot
What is bovine foul in the foot?
bovine interdigital phlegmon
What bacteria are in bovine foul in the foot?
*Fusobacterium necrophorum
*Bacteriodes melaninogenicus
What is the clinical signs of foul in the foot?
*Severe lameness
*Animal holds leg in the air to relieve pressure
*Swelling of interdigital space
*Fever
*Anorexia
*reduced milk yield
What is the treatment of foul in the foot?
3 day systemic penicillin, oxytet / macrolide
TOPICAL NOT EFFECTIVE
What is the control of foul in the foot?
Footbathing with disinfectants
What is an infection reservoir of foul in the foot?
Environment + manure
