Following periods of prolonged rain, outbreaks of foot rot appear in cattle, sheep and goats, even those kept under extensive production systems. Humid, warm conditions favour the organisms responsible. Foot rot can be a major disease problem under intensive dairy production systems. Other factors such as breed and housing are known to influence the occurrence and severity of the disease. Under intensive systems where exotic breeds are kept the disease occurrence is more severe than in extensive systems where most indigenous breeds are normally kept.

Fusobacterium necrophorum is considered to be the major cause of Foot Rot in cattle although other bacteria such as Bacteroides species can also be involved. Fusobacterium necrophorum can be isolated from faeces which may explain why control is difficult. The organism is a normal resident of the environment of cattle. Injury to the interdigital skin provides a portal of entry for infection. Maceration of the skin by water, faeces and urine may predispose to injury. The animals contract the disease when they walk in wet, muddy places where infected animals have been. It can also start after an injury to the foot. The disease has negative economic consequences to the farmer because it hinders the animal from feeding at the time when there is plenty of good feed.

Adult cattle are more commonly affected than younger animals and Bos indicus cattle appear to more resistant than those of European breeds.

In sheep there are two degrees of Foot Rot - Benign Foot Rot and Virulent Foot Rot plus another called Ovine Interdigital Dermatitis. In Virulent Foot Rot two organisms are required to initiate infection - Fusobacterium necrophorum and another called Dichelobacter nodosus. The former lives in the sheep's environment, the latter in carrier sheep and the latter is required for transmission. It cannot live for more than two weeks on soil or pasture but according to its degree of virulence sheep develop Benign or Virulent Foot Rot or Ovine Interdigital Dermatitis. In Virulent Foot Rot very severe lameness is caused with serious damage to the hoof.

Foot rot in cattle is a subacute or acute necrotic infection originating from a lesion in the interdigital skin that leads to a cellulitis in the digital region. Pain, severe lameness, fever, anorexia, loss of condition and reduced milk production are the major signs. The condition in cattle is usually sporadic, affecting individual animals. Usually one limb only is affected, usually a hind leg. Open lesions can become infected with secondary invaders and the interphalangal joint can become infected. Typically the claws are markedly separated, the inflammatatory oedema is uniformly distributed between both digits, the animal is reluctant to bear weight on that foot,the skin between the toes is discoloured, later it begins to slough and has a whitish appearance and has a foul smell.

Foot Rot in sheep is a herd disease, unlike the condition in cattle and must be treated as such. Lameness may be severe such that the sheep remain recumbent or on their brisket and knees. Sheep lose condition, rams may be unable to serve, wool prouction is reduced and areas of the hoof become detached and maggots may invade infected areas.

Move the animals to sandy (drier) places to control foot rot. Keep the ground clean and dry, especially in bomas

With regard to cattle drain areas around drinking toughs, gateways and frequented tracks. Contaminated concrete must be frequently cleaned and scraped free of manure. Preventive use of a footbath with an antiseptic and astringent solution eg copper ir zinc sulphate- 7 - 10% in water - is beneficial.

Regarding sheep any sheep added to the flock must be examined for evidence of Foot Rot and if lesions are found these sheep should either be treated and isolated for a month, or rejected. All sheep in the flock must be treated and any which do not respond to treatment should be culled. Alternatively two flocks should be created - a clean flock and one separate from the group with no lesions.