Background: A new canine subgroup defined as 'old-dog' or 'hyperkeratotic' erythema multiforme (HKEM) with marked hyperkeratosis and parakeratosis has been proposed without any detailed description of larger case series.
Objectives: We report herein the signalment, clinical signs, treatment outcome, and histopathological and immunological findings in 17 dogs with HKEM.
Animals: Inclusion criteria were the presence of (i) scaly skin lesions with or without crusting; and (ii) microscopic lesions typical of EM (i.