Bovine lameness is an important condition in commercial dairy and beef operations worldwide. Its economic impacts include decreased reproductive performance and milk yield and increased culling rates, milk losses and labor. One relatively new finding in the field of lameness is the non-healing lesions (NHL) such as toe necrosis (Blowey, 1999; Tozzo, 2000) and wall ulcers (Holzhauer, 2008; Cook and Burgi, 2008). These lesions typically are unresponsive or poorly responsive to standard treatments, have a moist granular appearance on exposed corium and a distinct fetid and pungent smell, and have been associated with Treponema spp, the etiologic agent of Digital Dermatitis (DD) (Blowey, 2011; Evans et al, 2011). To date, there have been no reports of the findings of this type of non-healing lesions in Argentina.
Materials and Methods
A field study was conducted in three dairy herds, ranging from 300 to 1.200 lactating cows in two different dairy regions in the Buenos Aires Province, Argentina. The herdsmen were asked to select lame cows after the morning milking. They were mobility scored by a team of veterinarians and then had their hooves examined. Lame cows with clinical lesions were examined and their hooves trimmed (n=20).
All animals were given a mobility score 3 (scale 0 to 3). The findings included toe necrosis (n=3), nonhealing sole ulcers (n=7), non-healing white line disease (n= 3) without clinical evidence of BDD, other lesions such as wire cuttings (n=3) and typical DD lesions (n=4). All of the non-healing lesions observed involved extensive loss of horn and damage to corium. In one particular case, the pedal bone was exposed. All non-healing lesions had a characteristic pungent fetid smell and a topical, wet and bright red colored granular appearance.
To our knowledge, this is the first report of non-healing lesions in dairy cows in Argentina, although we are aware of unpublished reports of a recent increase in similar lesions in Uruguay and Chile. Further studies are to be conducted to establish the epidemiology and etiology of the lesions observed in this study and their impact in dairy production in Argentina.