Keratoma of the Hoof - Equine
This patient had a history of an undiagnosed lameness of three years duration. All previous radiographic studies and lameness exams had failed to establish a diagnosis.
A physical examination verified a lameness in the right hind limb but could not localize an etiology.
Physiological Screen with Digital Thermal Imaging
The patient was acclimated to environmental temperature, was not handled during acclimation, and remained calm during image capture. Digital thermal images were captured with a Digatherm IR camera.
Interpretation of the Thermal Images
In an anterior to posterior oblique image of the right hind foot, an area of hyperthermia was noted originating from the coronary band and extending distally throughout much of the hoof wall (Fig. 1).
Fig. 1 – Anterior-posterior thermogram of the right hind foot.
The digital thermal image of the right hind foot convinced the owner that an MRI was appropriate.
The MRI revealed a previously undiagnosed keratoma, located between the hoof wall and underlying structures (Figs. 2 & 3). This corresponded to the area of hyperthermia noted on the digital thermal image.
The patient was referred for surgical removal of the keratoma.
Fig. 2 – MRI of keratoma of the right rear foot.
Fig. 3 – MRI of keratoma of the right rear foot.
Thermal images of the left hind limb displayed hypothermic areas encompassing the entire distal limb from the distal regions of the hock to the entire hoof (Figs. 4 & 5).
The owner reported that a previous surgery on the left hock for removal of a chip fracture had resulted in a chronic, palpable coolness to the touch in the hypothermic area.
This finding is compatible with surgical nerve damage resulting in chronic vasoconstriction in the distal limb.
Fig. 4 – Anterior oblique digital thermal image of the distal rear legs.
Fig. 5– Anterior oblique digital thermal image of the distal rear legs.
Kelly Jewell, MSc
Weston-super-Mare, United Kingdom