Radiography uses electromagnetic radiation that is projected onto the part of the horse under investigation. The denser the tissue, the more it absorbs the radiation and shows up as white on the radiograph.
Horses need to be anaesthetised for thermography.
Tick the advantages for Thermography.
Relatively cheap.
Only used on limbs.
Can indicate pain up to 3 weeks before the horse exhibits any clinical signs.
Non-invasive and can be done in the field.