Lameness is the third most significant cause of economic loss in the dairy industry, behind reproduction problems and mastitis. Pain from weight bearing on sore feet can cause a decrease in feed intake, milk production and body weight. The combined effect of all these factors can also influence reproduction. The longer the pain lasts, the greater the economic loss.
Hairy heel wart, or Papillomatous Digital Dermatitis, is a major problem causing lameness in dairy cattle. It is estimated that 70% of all US dairy herds have hairy heel wart. The disease is not fully understood, but is believed to come from a spirochete-type anaerobic (non-oxygen utilizing) bacterium that produces wart lesions.
The lesions from hairy heel wart are usually found at the back of the rear feet, near the heel bulb, or between the dew claws. The hairy heel wart bacteria proliferates in the anaerobic environment of slurry and enters through open sores in the cow’s foot.
A primary cause of open sores on the cow’s feet is ammonia gas. The ammonia hydrolyzes from the urea in urine, and burns the hide on the cow’s heel. This burning of the heel tissue results in open sores that are susceptible to invasion by the heel wart bacteria.
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