Serum concentration and skin tissue expression of insulin-like growth factor 2 in canine generalized demodicosis.

Background: There is increasing evidence that insulin-like growth factor-2 (IGF-2) levels are altered in skin injury; there are no data evaluating the serum concentration and skin tissue expression of IGF-2 in canine generalized demodicosis.

Hypothesis/objectives: To assess serum concentrations of IGF-2 collected from dogs with generalized demodicosis compared to healthy dogs and to determine the location of IGF-2 in the skin of affected dogs.

Methods: Blood and skin samples were collected from 12 dogs of differing breeds and gender at 1-2 years of age that had a confirmed diagnosis of generalized demodicosis. Age-matched control skin and blood samples were collected from 11 normal dogs of different breeds and gender. Serum IGF-2 concentrations were measured by enzyme-linked immunosorbent assay. Skin tissue expression of IGF-2 was analysed by immunohistochemical methods.

Results: Serum concentration and skin tissue expression of IGF-2 were increased in dogs with generalized demodicosis compared with control dogs.

Conclusions And Clinical Importance: These findings indicate that keratinocytes, histiocytes and fibrocytes in the dermis are positive for IGF-2; they may be a source of the elevated serum IGF-2 levels in dogs with generalized demodicosis.