DISTRIBUTION AND APPEARANCE OF ELASTIC FIBERS IN THE DERMIS OF CLINICALLY NORMAL DOGS AND DOGS WITH SOLAR DERMATITIS AND OTHER DERMATOSES

Objective-To determine the distribution and amount of elastic fibers i n the dermis of clinically normal dogs and dogs with dermatoses, parti cularly solar dermatitis. Design-Skin specimens from 7 anatomic sites were obtained from 19 clinically normal dogs after euthanasia to evalu ate the normal distribution of elastic fibers. Biopsy specimens also w ere obtained from 34 dogs with dermatoses, including 16 with solar der matitis. Tissue sections were stained with H&E, Verhoeff-van Gieson, a nd periodic acid-Schiff. Animals-19 clinically normal dogs and 34 dogs with dermatoses. Procedure-Numbers of elastic fibers were graded subj ectively. Comparisons between clinically normal dogs and dogs with der matoses were made. Results-Normal elastic fibers were present in low n umbers in the dermis of adult dogs, regardless of anatomic site or pre sence or severity of dermatitis. Condensed elastotic material was visu alized in only 2 dogs with solar dermatitis. In both dogs, the elastot ic material was Verhoeff-van Gieson and periodic acid-Schiff stain pos itive but was not visible with H&E stain. The most frequent histopatho logic finding in the dermis of dogs with solar dermatitis was superfic ial dermal fibrosis. Conclusions-The dermis of clinically normal dogs does not contain abundant elastic fibers. Alterations of elastic fiber s in dogs with solar dermatitis are rare. Superficial dermal fibrosis may be a better indicator of solar damage.