The Basics of Foot Rot

by Heather Smith Thomas

Foot rot causes swelling, heat, and inflammation in the foot, and severe lameness. Swelling and lameness appear suddenly. One day the animal is fine, and the next day the foot is so sore the animal may not put any weight on it.

Several bacteria can cause foot rot, but most common is Fusobacterium necrophorum, according to Dr. S.D. Lincoln, Caine Veterinary Teaching and Research Center, University of Idaho. Cattle pick up infection if there's a break in the skin. Wet areas, where cattle walk through mud, are likely places to pick up foot rot. The skin of the feet becomes softer and more tender when wet, so foot rot is common in wet weather or when cattle walk through wet ground, says Lincoln.

Symptoms
Once bacteria gain entrance to the foot, inflammation starts quickly. Generally the swelling is around the coronary band just above the hoof, between the toes or at the heel, depending on site of entry. Toes on the affected foot may become quite spread apart by the swelling. The enlargement may include the whole foot above the hoof, extending upward past the fetlock joint in some cases.

If an animal has foot rot more than a few days, there will be noticeable weight loss. Lameness hinders travel to feed and water, or severely cuts down on time spent eating; the animal spends most of its time lying down. Swelling in the foot usually breaks and discharges pus after a few days. This drainage contains bacteria and can further contaminate the pen or pasture.

Treatment
Many cases of foot rot eventually clear up without treatment, but the animal is lame longer, and spreads the bacteria while the foot is discharging. It's always better to treat foot rot; if cleared up quickly, there will be less contamination of the pen or pasture, and less risk of permanent damage to the foot.

With treatment, most cases heal swiftly, especially if caught early--preferably first or second day of swelling and lameness. Most cases don't need more than three to five days of antibiotics. Long-standing cases may be hard to clear up, and the joint or tendon sheaths may be permanently damaged.

Dr. Lincoln recommends long acting oxytetracycline or procaine penicillin for footrot, and says sulfa drugs are also effective in acute cases. Severe cases clear up faster if sulfa and tetracycline are used together--for three to five day. Disappearance of lameness is a sign of recovery.

"In chronic cases it may be necessary to clean the wound, apply local antiseptics, and bandage the foot, in conjunction with systemic therapy," says Lincoln. "If joints or tendon sheaths are involved, the prognosis for recovery is poor, and surgery to remove an affected claw may be the only option."

Prevention
Any management procedure that eliminates hoof damage and aids hoof health can help prevent footrot, says Lincoln. Clean pens--free of stones or frozen rough ground--to minimize hoof injury and infection in feedlots. "Footrot in feedlots can often be avoided by thoroughly cleaning pens after cattle are removed, and liberally spreading lime over the pen surface. Leaving the pen vacant for at least a week after liming helps control footrot organisms. Maximum drainage is essential to any feedlot arrangement and helps prevent constant contact with manure-laden mud or water," he says.

One of the best prevention measures is use of mounds of soil or bedding where cattle can be on dry ground. Concrete slabs also give a dry place to stand. "Use of concrete around water fountains and feed bunks where animals frequently congregate are most helpful in preventing contact with extremely wet, muddy conditions." He also recommends good nutrition for preventing footrot.

There is now a vaccine--F. necrophorum bacterin--for control and prevention of footrot, says Lincoln, and tests have shown a 64 percent reduction in cases when vaccinated cattle were compared to nonvaccinated animals. But Lincoln feels that "total reliance on vaccination for control is unwise. The bacterin should be used in conjunction with other time-tested preventative measures such as maintaining good hoof health." ©