OVINE foot rot was first reported in 1869. It is an infectious, contagious disease of sheep that causes severe lameness and economic loss from decreased flock production. Contagious foot rot is caused by the synergistic action of two anaerobic bacteria.

The bacterium Fusobacterium necroborum, which is commonly present in soil and manure, colonizes the soft tissues between the toes of the sheep. This is followed by penetration of the skin by a second bacterium, Bacterioidio nodusus. Both bacteria have to be present to cause foot rot, along with improper environmental conditions. There are around 20 strains of B. nodusus, with various infective capacity and severity of infection. When controlling foot rot, it is the B. nodusus organism that most attention is focused towards. Environmental conditions conducive to outbreaks of foot rot are warmth, moisture, and an anaerobic (no oxygen) state.

Foot rot is also introduced to the flock by another sheep infected with the disease. The B. nodusus organism will live in the soil for 14 days and this facilitates the sheep-to-sheep infection. Lameness is usually the major sign of an infected animal, even though the animal might not exhibit this vital sign during the early stages of infection. The area between the toes first becomes red and moist. Then the infection invades the sole of the hoof, undermining and causing the separation of the horny tissues. The infection causes a foul odour and may infect more than one foot at the same time. Not all lame sheep have foot rot. Before taking an eradication or control programme, it is best to consult a veterinarian for positive diagnosis and advice. Foot rot bacteria can live in cracks, crevices, etc. of the sheep’s feet for an extended period of time, thus the sheep can serve as a carrier for a period without any symptoms. This is an important consideration when trying to prevent foot rot.

Other conditions related to foot rot are foot abscesses, and foot scald. Abscesses can be caused by punctures by sharp objects and are not always related to foot rot. Foot scald is often a precursor to foot rot.

The least expensive method of controlling foot rot is by prevention. Ever so often, carrier animals are introduced into a flock after purchase without being quarantined. After purchasing an animal, it is always recommended that it is tested and checked for illness and infection before it is introduced into the flock.

Treatment Available
Today, there are various techniques available for the treatment of foot rot, and these range from foot baths, foot trimming, oral therapy, and foot rot vaccine. The use of portable equipment has also been proven to be of great help in the fight against this infection.

Since the organism that causes foot rot is anaerobic, the introduction of oxygen to its environment will help eradicate it. Thus, it is important to keep the animal’s hooves trimmed. The elimination of overgrown hoof tissues will result in less mud and manure accumulation which aids in the environmental condition conducive to foot rot development.

When treating foot rot, the following steps should be taken:

* Isolate the infected animal from the flock;

* Trim hooves on all the animals;

* Be careful not to spread foot rot to non infected animals by using contaminated hoof trimmer, pocket knives or any other equipment.

After trimming, use a foot bath made up of copper sulphate solution (10% w/v). This can greatly eradicate the disease. For the best results, the animal should be made to stand in the foot bath for at least five minutes, two to three times a week. Also, when trimming the hooves of a severely affected animal, allow for the penetration of the copper sulphate solution. The use of copper sulphate can be toxic to the animal if consumed. There are several solutions that can be used immediately after paring. These are oxytetracycline in alcohol, and copper sulphate in pine tar.

Vaccination of animals with a history of foot rot can aid in the prevention of animals from being stricken with this malady and the treatment of current cases. However, just because a sheep has been vaccinated for foot rot doesn’t mean it is immune to infection. The vaccine doesn’t cover all the strains of the disease.

Antibiotics can also be used to help treat cases of foot rot. Please consult your veterinarian before using antibiotics. Antibiotics should not be used on animals that are intended for slaughter before an adequate withdrawal time.