Locomotor disorders in small ruminants Flashcards
What is the most common cause of lameness in sheep
= ‘scald’ Interdigital dermatitis
What is a toe granuloma caused by
= proliferation of highly vascularised connective tissue
Can be a response to excessive paring and exposure of the corium
May treat via surgery but potential for regrowth
Which antibiotic is in blue spray; useful long acting one
Oxytetracycline
What is the causative agent of interdigital dermaitits (scald)
Dichelobacter nodosus
Present with acute lameness and interdigital inflammation
What can happen when scald is left untreated
Can develop into footrot
How does footrot develop
With untreated interdigital dermatitis; some strains of D nodosus will produce proteases that liquefy horn and cause separation from underlying tissues (starts at heel)
Present with pain, foul discharge, down on knees
What are predisposing factors for footrot
High density and poor hygeine, wetness, untreated scald
+ breeds e.g Merino and Dorset horn
How can we protect against scald/footrot
Good hygiene
Vaccinate; FootVax = D nodosus vaccine
Quarantine
Foot bath use
What medication must we NOT use in sheep vaccinated against D nodosus
Moxidectin
What chemical options do we have for footbaths
1) Formalin: 3-5%
2) Copper sulfate: 5%
4) Zinc sulfat: 10% NB needs 2-3 mins contact time
What can be added to footbaths to increase the penetration of the chemicals
lauryl sulfate
Which bacteria species are involved in CODD syndrome (contagious ovine digital dermatitis)
Spirochaetes e.g Tremponemas
F necrophorum and D nodosus
When do we get more severe, progressive CODD
When there is pre-infection with scald and footrot
Treating CODD
ISOLATION IMPORTANT
- Very sensitivie to amoxycillin/penicillin
- Can give long acting macrolides but expensive
How does contagious ovine digital dermatitis spread
From sheep to sheep
And from cows to sheep