 Picture: © Bayer Animal Health
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Even with treatment, digital dermatitis or foot warts remain a chronic problem for many dairy herds. Steven Berry, dairy health and management specialist at the University of California-Davis explains, `Research shows that up to 60 percent of cows that are successfully treated for foot warts have a recurrence within seven to 15 weeks.`
Maybe a new vaccine will change the situation...
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This level of recurrence wasn`t surprising, because animals remain in the same environment where they contracted the disease.
Berry recently made the remarks in a meeting with about 100 foot trimmers in Wisconsin Rapids, Wis. In a UC-Davis study, 22 cows with foot warts were treated with two antibiotics. After three weeks, warts were visibly healed in 18 of the animals. But 10 of these cows still had microscopic evidence of lesion activity in their hooves.
Three factors play an important role in the prevention of digital dermatitis including environment, bacteria and management, Berry explains.
Foot warts, or hairy heel warts, are associated with wet, muddy conditions. In a UC-Davis study to determine how the disease is transmitted, researchers found that foot warts only occurred when hooves were exposed to constant moisture with low exposure to air.
UC-Davis researchers have isolated three types of Treponema bacteria in hooves infected with hairy heel warts. Treponema are anaerobic bacteria, therefore hooves caked in mud are far more susceptible to foot warts.
Management: frequent alley scraping and other manure management techniques can help control foot warts, as well as routine copper sulfate footbaths.
Berry suggests isolating purchased animals for at least a month because the disease is believed to have a three-week incubation period.
With a grant from the California Milk Advisory Board, UC-Davis is currently conducting field trials with Treponema Bacterin, a vaccine for foot wart prevention from Novartis. Results from the five-location trial are due later this year, Berry adds.
Source: Foot warts can be a chronic problem, expert says. In: DVM Newsmagazine May 1, 2003. www.dvmnewsmagazine.com/dvm/
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