Variations in skin biophysical parameters with age, sex and breed in dogs

Background: Understanding the physiological and biophysical characteristics of skin provides information for developing appropriate management strategies for skin diseases. However, in dogs, variations in skin biophysical parameters, such as age, sex and breed, remain poorly understood. Hypothesis/Objectives: This study analysed three biophysical characteristics of healthy dog skin (hydration, pH and sebum content) and investigated the effects of sex, age and breed. Materials and Methods: One hundred forty-nine dogs without skin problems were enrolled. Skin hydration, pH and sebum content were measured using a multifunctional skin physiology monitor. The dogs were divided into four age groups: <1 year, 1–6 years, 7–12 years and >13 years. Results: Skin hydration levels were significantly lower in the >13 years group than in the 1–6 years and 7–12 groups. Additionally, skin pH levels in the >13 years group were significantly lower than in the 7–12 group. Furthermore, skin biophysical parameters among the five breed groups – beagles (n = 37), Malteses (n = 18), miniature poodles (n = 24), cocker spaniels (n = 11) and Pomeranians (n = 12) – revealed that skin hydration and pH were significantly higher in beagles than those of Malteses and miniature poodles. Conclusions and Clinical Relevance: These findings indicate that biophysical properties, including skin hydration and pH, vary with age and breed. This study provides fundamental data on the effects of age, sex and breed on the biophysical characteristics of dog skin.