Foot Rot in Sheep/Goats

In sheep/goats Foot Rot is a serious herd problem that can affect many sheep/goats and spread rapidly through the entire flock. In most cases more than one foot is affected.

Causes

In Foot Rot two organisms are required to start the infection - Fusobacterium necrophorum and Dichelobacter nodosus. Fusobacterium lives in the sheep's guts and environment and can also affect cattle. Fusobacterium alone cannot cause Foot Rot. Dichelobacter lives only in the affected hooves of carrier sheep/goats and is the main cause for foot rot. During rainy Dichelobacter can survive for maximum two weeks on soil or pasture and infect more sheep/goats. Foot Rot is transmitted via the contaminated environment. If healthy sheep/goats share pasture, watering points and/or the boma with Foot Rot infected sheep/goats they pick up the infection while passing through contaminated areas

Signs

• In sheep/goats the first sign is mild lameness
• When examining the feet of a sheep/goats in the early stage of Foot Rot you can see inflammation of the skin between the hooves
• In more advanced cases the infection begins to spread into the hoof and parts of the hoof begin to separate from the bone, separation spreads under the sole and finally the outer wall so that the horny hoof starts to come off. The dead tissue has a characteristic smell
• Severe Foot Rot causes the sheep/goat to loose its' hooves and walk on its knees while feeding
• Sheep/goats lose condition, rams stop to serve, meat, wool and milk production is down; because ewes and does have too little milk to support the lambs/kids many of them die
• The whole hoof may come off, the sheep/goats cannot stand up any more, maggots may invade infected areas and the sheep/goat has to be culled.

Prevention & Control

• If foot rot affects a flock on wet pasture immediately move the animals to drier places.
• For controlling Foot Rot keep sheep/goats in footbath containing a 10% zinc sulfate solution (10% is 100 grams per one liter of water); adding a little bit of laundry detergent (e.g. Omo) improves the effectiveness of the footbath; the sheep/goats have to remain standing in the foot bath for 1 hour. If no zinc sulfate is available you can also use 10% copper sulphate solution or 5% formaldehyde solution for the foot bath; in this case sheep/goats only remain in the footbath for 5-10minutes.
• The small liquid foot bath in picture above consists of a plastic tray lined with a 5-cm thick layer of foam plastic. The foam is covered by a stout plastic sheet. The tray contains a medicated fluid. As the animal walks on the surface, the foam and plastic are depressed and the liquid flows in. The swirling action of the liquid brings affected tissue into contact with the medication.
• The footbath should be repeated every 5-10 days for 3 treatments.
• Regarding sheep/goats 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 and goats in the flock must be treated at the same time 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 foot lesions; examine all feet at least once every two weeks

Treatment

• Careful examination of all feet; all loose dead material on the hooves and any overgrowth must be trimmed using a clean pen knife, this should be done before putting sheep/goats through the footbath
• Caution: when trimming the hooves inexperienced people may cut too deep causing extra injury - it is very good to watch an experienced herder trimming hooves and learn from him
• In addition Penicillin/Streptomycin given IM at double the recommended dose for three days is effective

The success of any treatment is much greater if the sheep are kept in a completely dry environment after treatment. The feet of treated sheep should be examined every 1-2 weeks to identify those needing further treatment.

Application of aerosol spray to cure fot rot

© William Ayako, Kari

Diseases with similar signs/symptoms

• Foot abscesses in sheep/goats. These abscesses are caused by injury of the skin just above the hooves. The injury results from sharp objects like sharp thorns and hard stubbles. This disease leads to lameness in many animals, but affects mostly only one foot. When examining the affected foot a localized abscess containing pus is visible on the skin above the rim of the hoof. This abscess may be very deep and even affect the joint. But unlike Foot Rot the foot abscesses do not affect the hooves and do not cause the hoof to come off. Early treatment with antibiotic injections is often effective and may prevent joint infection. Once the infection becomes established in the joint, treatment is very difficult.
• FMD (Foot and Mouth disease, see above)
• Bluetongue can also cause mass lameness in sheep/goats.