Minimal erythema dose (MED) in normal canine skin by irradiation of narrow-band ultraviolet B (NB-UVB).

Narrow-band UVB (NB-UVB) is light over a very narrow band of wavelengths (around 311 nm) that is concentrated in the therapeutic range and minimally in the sunburn range. It has therefore become the phototherapy treatment of choice for skin diseases. The minimal erythema dose (MED) on canine skin for standardizing dosage schedules in NB-UVB treatment and histopathological analyses were performed in these dogs. In all 32 dogs tested, the MED ranged from 432 to 864 mJ/cm(2). There were no significant differences in MED among breeds, sex and age groups. Histopathology obtained from areas irradiated by MED showed only mild vascular dilatation. These findings might be valuable for the application of NB-UVB phototherapy to canine skin diseases.