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