The Main Causes of Lameness
Contagious Ovine Digital Dermatitis (CODD)
Since 1997 some flocks have had very severe outbreaks of virulent footrot. Close inspection of some of these cases shows that the lesions start on the coronary band and not in the interdigital space. Sheep are severely lame with a high percentage affected. There is often rapid shedding of the whole horn case leaving a raw digital stump. The condition may spread rapidly with often 30-40% of the flock affected.
The essential difference between conventional footrot and CODD is the origin of the initial lesion at the coronary band. These lesions are ulcerative and proliferative and progress to extensive under-running, with complete detachment of the hoof in severe cases. The cause of the condition is not yet understood, although a variety of bacteria, including spirochaetes have been identified in affected feet.
Foot of sheep infected with CODD
It is essential that prompt veterinary advice is sought. Conventional antibiotics and footbaths used for true footrot are not entirely effective. Effective treatment usually involves the use of specific restricted antibiotic injections and footbaths. See Section on Treatment of Lameness for further details.
In muddy conditions, or in poorly bedded buildings, hard lumps of soil or muck collect and harden between the claws. These cause physical damage to the skin between the claws and may predispose the foot to scald.
Action to remove the encrustations, which may need to be softened prior to their removal.
This is a common condition in which the outer wall of the claw becomes loosened forming a pocket, which in turn becomes impacted with soil. If the soil is forced up under the hoof wall, then an abscess may form.
Judicious paring to remove loosened wall. This will prevent further impaction, the foot may require veterinary intervention if the condition is advanced.