Measurement definition
On a lateromedial hoof radiograph, sole depth is commonly measured from the distal tip of the third phalanx to the solar surface. On a dorsopalmar projection, medial and lateral depth can be measured separately using the corresponding P3 and solar references.
The measurement depends on a valid calibration factor and clearly visible endpoints. The radiographic definition should be recorded because values derived from different landmarks or imaging methods may not be interchangeable.
Acquisition factors
Review the following before using or comparing a sole-depth value:
- Weight-bearing and foot position
- Beam alignment and projection
- Visibility of the distal P3 margin and solar surface
- Calibration and magnification
- Presence and position of external markers
- Landmark placement
Research comparing radiographic and magnetic resonance measurements has demonstrated that measurement agreement varies by parameter and method. A radiographic value should therefore be interpreted as a measurement from that radiograph—not a direct substitute for another imaging modality.
Clinical interpretation
Sole depth is one component of the hoof assessment. It should be interpreted with the examination, history, hoof conformation, image technique, other radiographic findings, and management context.
No single universal threshold applies to every horse. Breed, foot size, age, use, pathology, projection, and measurement method can affect interpretation. DigiHoof does not classify a sole-depth value as diagnostic or prescribe a trimming or shoeing plan.
Serial use
Serial comparison is strongest when acquisition and measurement methods remain consistent. The veterinarian should review the original images as well as the numerical change.
DigiHoof retains the structured value, unit, limb, projection, examination date, calibration information, method version, and final landmark geometry. This supports retrieval and comparison after the source image reaches the end of its retention period.
References
- Grundmann INM, et al. Quantitative assessment of the equine hoof using digital radiography and magnetic resonance imaging. Equine Veterinary Journal. 2015.
- Measurements of equine foot parameters show limited agreement between radiographs and low-field magnetic resonance imaging. Veterinary Radiology & Ultrasound. 2025.
- Sellke L, et al. Measuring Equine Hooves in Radiographs and Computed Tomography Images Reveals Unexpected Size Differences. Anatomia, Histologia, Embryologia. 2026.