by Russ Daly
Special to the Farm Forum
When asked to consider the worst time of year for foot problems in feedlot cattle, most area cattle feeders would think of the hot, sometimes muddy conditions of summer on the northern plains. Many of those same producers, however, would also venture that they’re seeing a fair number of foot problems during our frozen winters.
Feedlot cattle lameness can result from a variety of causes. Any process injuring or infecting part of the affected limb, or sometimes even the spinal column, can make a calf gimpy. For example, muscle or joint damage after a slip on an icy surface is not uncommon in feedlots in our northern locales – but usually only affects a few unlucky animals.
When lameness issues become outbreaks, originating from a common root problem, cattle performance and well-being can be significantly affected. Cattle don’t want to move when they’re feet or limbs are sore. They’ll pass up that trip to the feed bunk or water tank in favor of staying where they’re at.
One of the most common causes of lameness “outbreaks” in feedlot cattle is foot rot, the medical term for which is “interdigital necrobacillosis.” Foot rot is a bacterial infection affecting most types of cattle and sheep. It occurs when the bacteria Dichelobacter nodosus and Fusobacterium necrophorum penetrate the skin in between the toes. A nasty, painful, odiferous infection of the skin and underlying tissues results. To the observer, the animal is lame on the infected foot, and a uniform swelling can be observed above the hoof.
In summertime, hot conditions spur animals to cool off by standing in mud or water. This frequent exposure to moisture weakens the normal defenses of the skin and allows these bacteria (which are present everywhere in cattle environments) to penetrate and cause infection. It’s this moisture exposure that makes hot summer conditions a common time of year for foot rot.
We’re finding, however, that wintertime does not give feedlot cattle a break from the risk of foot rot. In frozen conditions, the foot rot bacteria find their opening into the skin through small scratches and abrasions caused by cattle walking on uneven, sharp, frozen clods of dirt or manure.
Foot rot is a treatable condition, and an antibiotic injection can quickly get a lame calf back on track. But it’s much better to never let this painful condition get started in the first place. Wintertime foot rot control means paying attention to the pen surface. Using a box scraper to remove large frozen clods of icy manure, creating a more even (but not slick) surface for cattle to walk on is an effective prevention method.
This attention to pen environments is a much better fix for foot problems than addressing infections after they take hold. Feed grade antibiotics are not labeled (and therefore are unavailable) for treating or preventing foot rot. Water medications and foot baths may help, but are logistically challenging in freezing weather.
Cattle raised in monoslope buildings don’t get a free pass on foot issues, either. While these buildings take a lot of environmental variables out of the equation, frozen surfaces or persistent exposure to moisture can create feet issues here too.
Not every lameness outbreak is a result of foot rot. Infectious issues such as hairy heel warts (painful superficial sores on the heel above the hooves) and Mycoplasma infections (joint swellings) won’t respond to interventions that affect foot rot. Non-infectious issues affecting the whole group like toe abscesses and founder due to acidosis should also be on the list of reasons for a rapid increase in the number of lameness cases.
Because of these other causes of lameness, it’s critical to get feet problems diagnosed. This can’t normally be done with an eyeball over the fence. Close examination in a chute is a must.
Taking time to provide a good pen surface for cattle during the cold and snow of winter is not always convenient, but it will pay off with more mobile cattle that perform better. Once a problem crops up, a timely call to the local veterinarian for an accurate diagnosis, followed by a treatment and prevention plan, is the best way to go.
Russ Daly, DVM, is the Extension Veterinarian at South Dakota State University. He can be reached via e-mail at [email protected] or at 605-688-5171.