Jan. 21 2014 07:05 AM

Don't wait for your cows to tell you they have digital dermatitis; take steps now to keep it in control.

Digital dermatitis, commonly known as hairy heel warts, is a major cause of lameness on dairy farms. Digital dermatitis was identified in the early 1970s, came to the U.S. in the 1980s and has been a management challenge ever since.

Arturo Gomez, from the University of Wisconsin School of Veterinary Medicine, explained that digital dermatitis is caused by a combination of moisture, skin conditioning and the presence of bacteria. There are five stages of the disease:

M1 - subclinical stage
M2 - acute clinical stage
M3 - healing stage
M4 and M4.1 - chronic stages

"Chronic warts are the ones that cause problems on your farm," Gomez stated at the Leading Dairy Producers' Conference last week in Wisconsin.

It takes a combination of factors to keep digital dermatitis from flaring up. Gomez explained that constant inoculation to moisture and mud is not required. Even limited exposure to less-than-ideal conditions can lead to hairy heel warts, especially in more susceptible cattle like younger animals or fresh cows.

If a wart appears, early topical treatment is a must. This minimizes the risk for skin proliferation and long-term problems. To prevent an acute incident from turning into a chronic one, "Look for active cases and treat them quickly," said Gomez. "Don't let active cases go."

To turn chronic infections into acute ones, utilize a well-designed footbath. A study found that, in an industry standard length footbath (6 feet long), just over half of the cows put their back feet in twice. A footbath that accommodates at least two immersions per foot would be preferable.

"The dimensions of your footbath are as important as the solution you put in there," Gomez said. "Think first of the dimensions, then think about what you will put in there." Gomez reiterated that footbaths are used to avoid chronic stages of digital dermatitis; they are not used to treat small, active warts.

He also advised farms to hire a hoof trimming professional that "knows what he is doing." Prevention and catching problems early are critical. "You are not going to get rid of it if you are late," Gomez stressed.

"Don't wait for cows to tell you they have digital dermatitis," he said. "By then, you are too late."

Abby blog footerThe author is an associate editor and covers animal health, dairy housing and equipment, and nutrient management. She grew up on a dairy farm near Plymouth, Wis., and previously served as a University of Wisconsin agricultural extension agent. She received a master's degree from North Carolina State University and a bachelor's from University of Wisconsin-Madison.