Foot scoring is a means of objectively describing the severity of footrot lesions. Foot scoring has been used in diagnosis and to study the impact, treatment, and control of footrot.
A simple scoring system was developed by Egerton and Roberts (1971), ranging from Score 0 (healthy, with no signs of disease), through Scores 1 and 2 (interdigital skin lesions) to Scores 3 and 4 (severe lesions with underrunning of the sole of the hoof) (Figure 1).
Score 3 lesions were subdivided into 3a, 3b and 3c according to the degree of underrunning (Stewart et al., 1982b; Stewart et al., 1985) while Score 5 (more severe than score 4, with separation of the walls of the hoof) was defined later (Figure 1) (Stewart and Claxton, 1993; Anonymous, 1990).
Important points about foot scores:
- the underrunning of the keratin horn commences in the interdigital area at the axial margin of the heel and extends abaxially and towards the toe.
- underrun lesions of increasing severity include the area of less severe lesions.
- underrun lesions of the horn may or may not be accompanied by interdigital lesions, according to the stage of the disease (developing, resolving or covert).
- when lesions are long standing, there can be a healing response with overgrowth of keratin, leading to one or more of the following signs: multiple ridges on the axial hoof walls; multiple layers of horn on the soles; deformed hoof; massive overgrowth of the hoof. All of this can be accompanied by impaction of soil and faeces.
Please use the Dropdown menu or click on the links below to study images of Foot Scores of each grade:
Score 3, 4 and 5 lesions are severe: there is underrunning of the horn of the hoof.
Score 3 lesions can be subdivided in increasing order of severity: 3a, 3b, 3c. This is done mostly in research studies.
Figure 1. Schematic drawing of the plantar aspect of an ovine foot showing the extent of lesions of increasing severity: 1, 2, 3a, 3b, 3c and 4. Underrun lesions of increasing severity include the area of the less severe lesions. Underrun lesions may or may not be accompanied by interdigital lesions, according to the stage of the disease (developing, resolving or covert). Adapted from Whittington and Nicholls (1995).
The severity of disease in an individual sheep can be described in several ways including:
- maximum foot score – the score of the worst affected foot.
- average footscore – the mean of scores of the four feet.
- total foot score – the sum of the scores of the four feet.
- total weighted foot score – a summative measure that enables sheep with severe lesions to be distinguished from those that do not (Whittington and Nicholls, 1995).
These measures can be aggregated in order to describe the severity of the disease across a flock.
Sometimes it can be difficult to distinguish the different types of foot lesions. Please click on this link to look at the images in Foot score gallery
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