Lameness in dairy heifers: a narrative review of control strategies

Abstract

Lameness is a prevalent condition in mature dairy cows, but the common underlying diseases — sole bruising-sole ulcers, white line lesions and digital dermatitis — invariably arise from management factors in first lactation or rearing. The published evidence would indicate once infected by the Treponemes causing digital dermatitis, heifers retain these bacteria in the skin despite apparent clinical resolution, meaning the emphasis of control should be placed on minimising risk of early life exposure, largely through biocontainment, foot cleaning and foot disinfection. For sole bruising and sole ulcers, there has been a major switch from the acidosis and laminitis-base models of disease, to a biomechanical pathogenesis for claw horn lesions. This has focused attention on the development and preservation of the digital cushion, with the emphasis on preventive strategies combined with early intervention involving anti-inflammatory drugs among other things. This article reviews the evidence-based underpinning the rationale that heifers should be the focus of foot health control, a message that can be challenging to convey when the perceived problem invariably sits with how to deal with chronic, end-stage lesions.