What are trichograms and what use are they in making a diagnosis?
Quite simply, a trichogram is the microscopic examination of hair shafts. Quite a lot of information can be gleaned from this simple test. For instance, if a cat is losing its fur and there is no inflammation we can often prove that the fur is being chewed or licked off, as the ends of the hair shafts are frayed or blunted rather than tapering to a point. Certain diseases, such as black hair follicular dysplasia and colour dilution alopecia, can be determined by the appearance of abnormal clumping of melanin (pigment) granules in the hair shafts and roots.
Causes of ringworm can be diagnosed sometime by finding the fungal filaments invading the hair shaft if special stains are used. Hormonal alopecia will have the hair roots all in the same stage of the hair cycle.