February 8, 2016 - 8:31am -- Anonymous

Hoof trimming and treatment is a regular, consistent program on most dairy farms, the goal being to prevent, minimize and reduce issues with lameness and hoof health problems in the herd.  Lameness directly impacts productivity and profitability and in some cases may also become an animal welfare concern.  Most dairy operations are concerned about bacterial infections that lead to digital dermatitis.  The bacteria that cause digital dermatitis will produce a painful wart on the heel of the infected cow.

Digital dermatitis is also known as hairy heel warts and when severe enough can cause lameness.  According to a University of Kentucky dairy extension article authored by Alexis Thompson and Jeffrey Bewley and entitled “Understanding Digital Dermatitis”, the wart-like growths are classified in 5 categories including not present, small growth, large growth, healing and chronic.   Digital dermatitis in the large growth and chronic growth categories can produce lameness.  Cows that have more severe warts tend to walk on their toe, which wears down the toe.  Early detection of digital dermatitis can increase the possibility of successful treatment and reduce animal suffering.    If controlled, the bacteria can go dormant, but will become active again if there is irritation.  Infected cows with large growth warts or cows classified as chronic can transmit the bacteria to non-infected cows.

Digital dermatitis, especially when it leads to lameness is costly.  Lame cows have decreased feed intake, lower milk production and poor reproductive performance.  The University of Kentucky article says that a case of lameness costs an average of $133.  An on-line article in Progressive Dairy from August 31 of 2015 says that there are estimates that put the cost of each case of lameness at close to $700 when the costs of treatment and loss of productivity are included. 

Hoof health is influenced by a number of factors.  An environment that is clean and dry helps to minimize hoof health problems.  Cows standing in manure are more prone to poor hoof health and manure acts as a breeding ground for bacteria that can infect hooves.  Another factor that impacts hoof health is stocking density.  Cows ideally will lie down for 12 hours a day.  That time in a stall lying down takes pressure off the feet, reduces the stress of standing on concrete and allows hooves to dry.  Quoting a University of Kentucky Extension dairy article; “The cleaner and drier the foot is maintained, the lower the prevalence of digital dermatitis.”  When stocking density is too high, access to freestalls is limited and timid cows spend more time on their feet, have less opportunity for hooves to be in a dry environment, and may have increased time standing in areas with more manure.  Production stage may also be a factor in susceptibility to digital dermatitis.  The University of Kentucky article by Thompson and Bewley says that transition cows are among the most susceptible to digital dermatitis because stress from calving and pen movements have reduced their ability to fight off infections.

Digital dermatitis is treated with foot baths, hoof trimming, topical medications and bandaging or wrapping.  A September, 2015 article in bovine vet online entitled “Rethinking claw-lesion treatment” reported on the results of a survey by Iowa State University veterinarian Dr. Jan Shearer regarding treatment practices for claw lesions and the outcome of those treatments.  The article stated that the use of topical medications was cited by 59% of the veterinarians and 53% of the hoof trimmers and that a bandage or wrap was considered a routine procedure for 53% of both veterinarians and hoof trimmers.  What is of interest, according to Dr. Shearer is that none of these treatment procedures are supported by scientific literature.  With regard to topical treatment Dr. Shearer says that there are no scientific studies documenting either a benefit or a detriment from the use of topical treatments.   A Cornell study indicates that bandages are unlikely to provide benefit and may even delay healing of claw lesions.  According to the article results of the survey may lead to changes in treatment decisions.

            Quoting from the article, the major findings of the study were:

  • Topical treatment may increase inflammation and delay healing and recovery rate of claw lesions.
  • Topical treatment with tetracycline, oxytetracycline and copper sulfate may increase post-treatment discomfort.
  • Topical tetracycline and oxytetracycline powder formulations may cause detectable residues in plasma and milk.

 

References: Click on the link for more information

Understanding Digital Dermatitis, Thompson and Bewley, University of Kentucky Extension

Managing and Controlling Digital Dermatitis; Thompson and Bewley, University of Kentucky Extension

Rethinking claw-lesion treatment; Wren, Bovine Vet online article

Mobility Matters: pay attention to hoof health, Henshaw Progressive Dairy article