Foot Problems In Sheep

There a number of different foot problems found in sheep. At this time of the year, grass seeds, footrot and scabby mouth tend to be the most obvious.

Grass seeds can penetrate the bare skin between the toes of sheep. Sheep become quite lame and the seeds can cause quite nasty infections. Grass seed penetration occurs more if moist conditions are present. Lambs or sheep infected with benign footrot are key candidates for grass seeds. Foot abscess can also predispose sheep to grass seed penetration in their feet. Foot bathing in a 10 per cent zinc sulphate solution will vastly improve the situation by reducing the level of infection and assists to dry out the area making it more difficult for grass seeds to penetrate.  Once the interdigital (bare skin) area is dry, grass seed penetration is not a problem. A consequence of foot bathing is to reduce the level of lameness in the flock.

The wetter than normal conditions experienced this year, in many parts of South Australia, will provide ideal conditions for the spread of ovine footrot. Footrot is a bacterial disease of sheep and goats caused by various strains of the bacteria, Dichelobacter nodosus. The bacteria need warm, moist conditions to survive and this means that the common spread time is from early spring to mid-summer.

The bacteria invade the sheep’s hooves and, once on the hoof, proceed to eat away at the soft horn/hard horn junction. Benign footrot or “foot scald” only causes reddening and wetness in the inter-digital area and some separation of the cracks on the internal walls of the hoof. However, occasionally there has been much more extensive damage done. In such cases, a proportion of the sheep become very lame. This is known as virulent footrot.

Merino sheep are more susceptible to footrot than British breeds and cross bred sheep.
In the spring of 2008, 80 sheep flocks in the high rainfall zone of South Australia were surveyed by PIRSA Animal Health personnel to ascertain the prevalence of benign and virulent footrot. 6.25% of flocks had virulent footrot. Benign footrot was detected in 25% of flocks.

From early October 2012 until the end of February, 2013 surveillance for footrot was undertaken in two abattoirs. There were a total of 477,000 animals inspected from 3,190 lines of sheep originating from South Australian sheep properties. There were only 11 of the 3,190 lines regarded as virulent. By contrast, there were 750 lines (23.5 per cent) of lines where benign footrot was detected.

Scabby mouth, whilst mostly seen on the mouths of sheep, it occasionally infects the feet. The condition is seen as a large infected/scabby area at the back of the foot or above the coronet. In most cases the disease will run its course, however sheep should be monitored to ensure feet do not become infected and/or fly struck.

If you see any feet conditions in your sheep you are unsure about, speak to your local vet, animal health officer or livestock consultant.

Further details on footrot are available in a new SheepConnect Tasmania Footrot Ute Guide.