|The response to treatment with four topical preparations was evaluated in an 11-year-old Morgan horse mare with histologically confirmed quadrilateral cannon hyperkeratosis.
Each limb was treated for 30 days with 0.1% tacrolimus ointment, 0.1% adapalene gel, 0.2% phytosphingosine spray or a water-based emollient.
Response to treatment was evaluated both histologically and visually.
A water-based emollient and 0.1% tacrolimus ointment produced encouraging clinical responses.
Pre-treatment histopathology identified marked, mostly compact, hyperkeratosis and follicular hyperkeratosis, most prominent in the infundibular area.
Following treatment, histopathology identified a mild reduction in follicular keratin production and stratum corneum thickness.
Source: Hugo Hilton, Verena K. Affolter and Stephen D. White (2008): Evaluation of four topical preparations for the treatment of cannon hyperkeratosis in a horse. In: Veterinary Dermatology
Volume 19 Issue 6, Pages 385 - 390