by Jo Woodnutt

Created on: May 07, 2011   Last Updated: May 12, 2011

Foot rot in sheep is caused by two bacteria, F.necrophorum and D.nodosus. It is common in sheep that are in wet, warm conditions, such as deep bedding in a barn, as well as sheep that have sustained trauma to the feet. F.necrophroum live in the gut and will therefore always be present in sheep faeces and on sheep feet. This bacterium enters damaged feet and creates perfect conditions for D.nodosus to live, providing an entrance to the hoof horn. Foot trimming sheep that do not need it is also considered to be a risk factor- large groups of sheep will tread over the same area again and again, and hoof trimmings possibly containing bacteria will be rife on the ground.

Prevention:

•Keep housing clean and dry, including changing straw regularly.

•Walk sheep through a foot bath of formalin or zinc regularly, including before and after being in indoor housing, or when moving to a new field.

• If possible, walking sheep through a stream regularly will keep the feet clean and avoid foot rot.

•Avoiding foot trimming except on an individual basis wherever possible.

•Give indoor sheep room to go outside- being out in the grass will clean out the feet and the cooler ground will provide less favourable conditions for the foot rot bacteria.

•There is a vaccine available, but it is expensive and is rarely used in most herds.

•Cull sheep that are lame with foot rot more than twice a year, or ones that do not respond to treatment.

Identification:

Sheep with foot rot can be identified at a distance by lameness, from a slight limp to refusing to use the foot entirely. On closer examination they often have overgrown feet, which may or may not have dirt caked in them. Removal of the dirt can reveal a characteristic foul smell and a sore-looking foot. In serious cases, the horn of the foot can be completely falling off, revealing a bloody foot beneath. The foot is likely to be warm.

Treatment:

Sheep with foot rot are best treated by trimming the horn (preferably in an area no other sheep will come into contact with) to ensure that nowhere can harbour dirt and muck. All dirt and muck around the foot should be removed as well. The foot should then be sprayed with antiseptic spray or dipped for at least 30 seconds in formalin. Isolate these individuals for at least 14 days if possible. The formalin/antiseptic treatment can be repeated every few days if required to ensure the feet are kept free of bacteria, or an injection of long-lasting antibiotics can be given.

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