by A.J. Tarpoff, DVM, MS, extension beef veterinarian
During the summer months many producers run into issues with lame cattle. The effects of lameness may show itself by decreased fertility, weight loss, decreased performance, and increased labor and medicine costs. It has been estimated that 88-92% of lameness in cattle stems from the foot. Several issues could be the culprit, but we will review some of the common causes and treatment considerations.
Footrot is a common disease process that occurs in pasture cattle. However, not every lame animal has footrot. Footrot is a bacterial infection of the foot. The name of the bacteria is called Fusobacterium necrophorum. However, other bacteria can be involved. These bacteria are found naturally in the rumen and manure of cattle. The skin is an amazing barrier and shield to the pathogens in the environment. An insult to the skin, more importantly the skin in-between the two toes, is necessary for the infection to take ahold. Breakdown of the skin can be caused by numerous mechanisms, but physical trauma is often the culprit. Walking on rough abrasive surfaces, rocky areas, puncture wounds from hard stubble or recently mowed pastures, or frozen/dried mud can all be the culprit. Once the bacteria break through the skin barrier, they release a toxin that causes necrosis and destruction of the cells. This cellular destruction leads to large amounts of inflammation that leads to swelling. The foot swells uniformly and obvious lameness occurs. Early in the disease process, swelling may be located on the backside of the foot under the dewclaws. As the disease progresses, the swelling can incorporate all of the space between the fetlock and hooves. Footrot also has a foul pungent type smell that is very indicative of those anaerobic bacteria.
Footrot occurs more commonly in wet humid conditions, but hot dry summers can have high rates as well. Hot dry conditions can lead to cracking and chapped skin in the interdigital space. Managing the external environment can be extremely difficult. Commonly visited areas of the pasture oftentimes are the culprit areas leading to footrot issues in the herd. These commonly visited areas could be wet, muddy areas around water bowls, shaded or resting areas, or mineral feeding areas. These areas will have increased amounts of environmental contamination, particularly from manure. Moving mineral and supplement sites, and monitoring water tanks for leaks can be helpful in limiting these conditions. Controlling access to watering sites in a pond can also reduce the threat.
Other control methods include proper mineral supplementation. It has been indicated that supplementing with proper levels of zinc and iodine may help reduce overall occurrence. There is a footrot vaccine available but there are mixed reports on overall efficacy. The vaccine does need 2 initial doses. It may help in some circumstances to reduce overall occurrence, but will not eliminate foot rot cases entirely.
Work with your local veterinarian to choose the proper treatment regimen. The treatment typically consists of an injectable antimicrobial. There are many antimicrobials approved for treatment of footrot, including oxytetracycline, tulathromycin, ceftiofur, florfenicol and sulfa products. Footrot is a painful condition. There is also a new topical flunixin product available to control the pain associated with this condition. Early treatment in the disease process is typically very rewarding. To find these cases, be sure to check mobility of all animals in the herd while checking and monitoring your pastures. Because as the disease progresses, deeper structures of the foot can be involved, making treatment difficult. If left untreated the infection can spread up the leg causing systemic issues or turn into a “club foot”. In these cases, salvage may be the only option for treatment. Contact your veterinarian to discuss non-responsive cases. Non-responders typically have involvement in the joints, bones, or tendons. If the swelling is consolidated to one toe, it may indicate a septic joint or a sole abscess. Surgical debridement and aggressive treatment by your veterinarian may be indicated to ensure return of function.
Treating cattle in a pasture has its challenges. Have a plan in place to restrain and properly treat cattle. As with any treatment, proper dosing, administration, and documentation is essential. Treating these cases early will help ensure treatment success, as well as a reduced impact on the performance of the affected animal.