It is treated with large doses of penicillin.This is what we do over here. Foot rot is fairly common due to wet, muddy pasture where the infection lives for up to two weeks.
Firstly, any animal who starts to limp should be inspected, ideally that same day. If foot rot is found, the animal should be isolated from the others and the others moved to clean pasture. Clean the foot up, use an iodine-based spray locally on the hoof and inject with a long-acting tetracycline. May need to be repeated after 3 days.
Our current guidelines say no foot trimming at all, even if the hoof is overgrown. The hoof has overgrown as it is not being worn off by the animal placing its full weight on that leg. Cutting back, particularly the aggressive cutting back (to 'fresh blood')which used to occur, meant the animal was being forced to walk on raw tissue and infection was being poured onto the walking surface. When the hoof becomes less painful and the animal can walk on it again, the hoof will wear off.If there's a large piece if broken hoof which gets filled with soil, then this can be pared back.
Over her a vaccine is available for flocks in which the problem is chronic.
Be sure it is foot rot and not Contagious Ovine Digital Dermatitis which starts in the area where the nail emerges from the leg. The animal is very lame, but the foot doesn't smell like foot rot.
We have a long plastic 'foot bath' into which we put formaldehyde solution. The sheep are run through the bath and then stand on a clean yard until their hooves have dried. The formaldehyde solution hardens the cleats of the hoof and also kills off bacteria. The foot bath is very useful when we have long, stringy wet grass which tends to cause scald in lambs in late spring.
