Foot rot is an annoying - not to mention smelly - problem for both cattle and producers. Though not difficult to treat, its management still takes up valuable time and labor.
Although specific economic data is not available, nearly 20% of farmers surveyed agreed foot rot had a significant economic impact on their cow-calf operations. That's according to a July 1997 National Animal Health Monitoring System (NAHMS) survey.
Also called foul foot or necrotic pododermatitis, foot rot is rated as the second most frequently occurring disease (after pinkeye - see BEEF, August 1997, page 42) in breeding females in cow-calf herds, NAHMS reports.
Painful Infection Foot rot is an infection in the soft tissue of the foot, causing a painful lameness that affects weight gain and breeding performance.
If left untreated, the infection can spread to joints, causing chronic arthritis. In severe cases, an animal can die from complications when the infection spreads throughout the body, veterinarians say. Few cases of foot rot result in death, however.
Still, the resulting damage can be severe if the infection is allowed to spread. "If the infection persists long enough that it provides damage to the joint ... you can sustain substantial loss because of weight loss," says Jerry Olson, associate professor of veterinary medicine at the University of Minnesota. "You have less to sell and the quality and grade of animal are reduced."
Bacteria Are The Culprits The bacteria responsible for foot rot (Fusobacterium necrophorum and Bacteroides melaninogenicus) live mostly in muddy areas. "They do well surviving in mud or wet filth," Olson says.
A cut in the foot lets the bacteria get into the foot's soft tissues. Also, chronically wet conditions can soften the feet, allowing bacteria to infect even if there is no wound, says Bruce Brodersen, veterinary pathologist at the University of Nebraska's Diagnostic Lab. Because the bacteria don't need oxygen to survive, they thrive in the deep tissue of the foot, developing an infection.
Tips For Prevention To avoid potential losses - and to save time and money on the labor to treat affected animals - you can use various methods to prevent foot rot in your herd. However, prevention costs should not exceed potential treatment costs. "Prevention becomes a site-specific issue," says Bill Epperson, Extension veterinarian at South Dakota State University.
Veterinarians recommend that cattle have adequate amounts of zinc, calcium and vitamin A in the diet for good skin health. Keep in mind, though, that too much of any nutrient can cause problems. "The key is balance," Epperson says. "Provide the necessary minerals, but not excessive amounts."
Some producers have prevention success in limiting cattle's access to very wet areas or rocky patches of ground by fencing them off, Epperson says. He also tells producers to vaccinate bulls before the breeding season, especially if they have a history of foot rot. However, the high cost of vaccines generally doesn't justify vaccinating the entire herd, he says.
In feedlot or drylot situations, the best way to prevent foot rot is to maintain the yard. Remove nails, wires and other objects that may cause injury to the feet. Also, keep mud at a minimum and make sure the yard is drained well, says Minnesota's Olson. "Dry is good," he says. Cement around feed bunks and waterers reduces mud and helps to keep the area dry.
Outside the yard, watch for things that could injure feet. Cows grazing on stubble, for example, are more likely to cut their feet, which increases their chances of developing foot rot, Olson says.
Treatment Options If prevention measures fail, foot rot is fairly easy to spot. "Because the animal's lame, it's very clear that something's wrong," Olson says.
Before diagnosing foot rot, rule out other causes of lameness, like a nail in the foot. The lameness in foot rot is usually followed by swelling, spreading of the toes, redness of the tissue above the hoof and, in more advanced cases, a foul odor as the flesh literally rots away because of the infection.
Treatment works best if you catch the disease before it spreads to the joints. "The key is early identification before the infection penetrates to deeper tissues and causes irreparable damage," Olson says. An animal can completely recover from foot rot if treated early.
Penicillin or other antibiotics are cheap cures for the disease in its early stages, veterinarians say. If foot rot is severe, it may be necessary to cut away the dead tissue, soak the foot in an antiseptic solution and bandage the foot.