Preliminary results point to high prevalence of Digital Dermatitis and Claw Horn Disruption

As of November 30, 2012, 578 herds in 3 provinces had contributed trim records and DHI data to The Alberta Dairy Hoof Health Project's hoof health database, providing trim records for 80,533 individual cows. In Alberta, 50.9% of these cows had one or more of the 14 claw lesions being evaluated by hoof trimmers. In BC, 59.8% of cows trimmed had one or more lesions while, in Ontario, only 38.1% had lesions.

  Alberta British Columbia Ontario
Participating Farms 158   85   335  
Total Distinct Cows 40,558   15,930   24,045  
...with Lesions 20,644 50.8% 9,523 59.8% 9,156 38.1%
Lesions:            
Digital Dermatitis 13,241 43.2% 5,464 37.9% 4,488 34.8%
Sole Ulcer 5,284 17.2% 2,149 14.9% 1,684 13.1%
White Line Lesion 4,760 15.5% 2,053 14.3% 1,106 8.6%
Sole Hemorrhage 1,964 6.4% 1,026 7.1% 2,894 22.4%
Toe Ulcer 1,504 4.9% 763 5.3% 213 1.7%
Interdigital Hyperplasia 1,141 3.7% 444 3.1% 968 7.5%
Thin Sole 728 2.4% 306 2.1% 128 1.0%
Foot Rot 733 2.4% 262 1.8% 133 1.0%
Heel Erosion 199 0.6% 91 0.6% 280 2.2%
Corkscrew Claw 403 1.3% 45 0.3% 155 1.2%
Interdigital Dermatitis 178 0.6% 1,612 11.2% 769 6.0%
Axial Fissure 270 0.9% 107 0.7% 40 0.3%
Vertical Fissure 204 0.7% 21 0.1% 30 0.2%
Horizontal Fissure 48 0.2% 62 0.4% 10 0.1%
Total Lesions 30,657 100% 14,405 100% 12,898 100.0%

Digital Dermatitis (DD) is by far the most common lesion among the cows examined, accounting for 40.0% of all lesions recorded. DD, commonly called 'hairy heel warts', 'Mortellaro's disease' or 'strawberry foot rot' is a contagious infection caused by bacteria that thrive in moist, low-oxygen (anaerobic) environments such as manure and wet, contaminated bedding.

Next in order of prevalence are 4 lesions related to 'claw horn disruption' (CRD): sole ulcer, white line lesion, sole hemorrhage and toe ulcer. Together these four lesions account for 43.8% of all lesions recorded to date. Traditionally, these lesions were thought to result from feeding high-energy diets, leading to ruminal acidosis and laminitis - inflammation of the small blood vessels in the claw-forming tissue of the hoof. More recent research evidence suggests that events around calving may cause structural changes in tissues that suspend the pedal bone inside the hoof or in the digital fat pad than provides a cushion under the bone.

30 November 2012