Protein Producers Winter 2016

Clinical Case Review: Foot Rot in Beef Cattle By: Lisa Taylor, Jose Valles and Dr. Tom Noffsinger, Production Animal Consultation and thank you to Dr. Dörte Döpfer, MSc, PhD, University of Wisconsin - Madison for your assistance with this clinical case review.

Foot rot, also known as interdigital necrobacilosis or interdigital phlegmon, is an infectious disease affecting the interdigital region of the bovine foot. Foot rot is a prominent cause of lameness in beef cattle which is associated with substantial economic losses for producers due to performance loss and treatment costs.

Foot rot cases are primarily caused by a synergism between Dichelobacter nodosus and Fusobacterium necrophorum. D. nodosus enters and resides in the epithelium when the interdigital skin is damaged by maceration or microtrauma. Protein break-down by D. nodosus facilitates growth and entry of F. necrophorum. In addition, increased inflammatory response and reduced leukocyte function induced by F. necrophorum lead to inflammatory reactions attracting purulent Trueperella pyogenes to the scene when toxins result in pus formation and tissue destruction. Other bacteria species, such as Bacteroides melaninogenicus, Escherichia coli, and Staphylococcus aureus may also be involved. Super foot rot, a particularly acute and rapidly progressing condition, is thought to involve an antibiotic-resistant strain of F. necrophorum.

Foot rot outbreaks are sporadic and can affect anywhere from a few animals to more than 25% of the herd. Cattle of all ages are affected, and cases are seen year round and worldwide. Cattle are more susceptible to foot rot infection in hot, humid environments or when housed on high-moisture surfaces, such as pens with high accumulations of manure, urine, or mud.

Foot rot usually affects only one limb. Infected cattle will commonly present sudden lameness in the affected limb. Because foot rot is painful, the animal will become hesitant to move. Other symptoms include decreased appetite and possible fever. In severe cases, animals may go off feed completely.

Simple locomotion observation is not adequate to accurately differentiate foot rot from other lameness diagnoses.

The animal must be properly restrained so the affected foot can be lifted and thoroughly examined.

First the foot should be properly washed or wiped clean up to the declaw area. Then the limb and interdigital region should be examined for pain, swelling, redness, lesions, necrotic tissue, and odor. Foot rot cases will present symmetrical swelling throughout the foot.

Three stages of foot rot are differentiated. In stage 1, sudpacdvms.com 21