Abstract
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.
Keywords: age, breed, dog, pH, sebum, skin hydration
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. 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.
Zusammenfassung
Hintergrund
Das Verständnis der physiologischen und biophysischen Charakteristika der Haut bringt Informationen, um entsprechende Managementstrategien für Hautkrankheiten zu entwickeln. Bei Hunden ist jedoch über die Variationen bei den biophysischen Parametern der Haut, wie Alter, Geschlecht und Rasse wenig bekannt.
Hypothese/Ziele
Diese Studie analysierte drei biophysische Charakteristika von gesunder Hundehaut (Hydratation, pH und Sebum‐Gehalt) und untersuchte die Auswirkungen von Geschlecht, Alter und Rasse.
Materialien und Methoden
Einhundertneunundvierzig Hunde ohne Hautprobleme wurden in die Studie aufgenommen. Haut Hydratation, pH‐Wert und Sebum‐Gehalt wurden mit einem multifunktionellen Haut‐Physiologiemonitor gemessen. Die Hunde wurden in vier Altersgruppen eingeteilt: <1 Jahr, 1–6 Jahre, 7–12 Jahre und >13 Jahre.
Ergebnisse
Hydratationslevels der Haut waren in der >13 Jahre Gruppe signifikant niedriger als in der 1–6 Jahre Gruppe und der 7–12 Jahre Gruppe. Zusätzlich waren die pH‐Werte der Haut in der >13 Jahre Gruppe signifikant niedriger als in der 7–12 Gruppe. Weiters zeigten die biophysischen Hautparameter unter den fünf Rassegruppen – Beagles (n = 37), Malteser (n = 18), Zwergpudel (n = 24), Cocker Spaniel (n = 11) und Pomeranier (n = 12) – dass die Hydratation der Haut und der pH‐Wert bei Beagles signifikant höher waren als jene der Malteser und der Zwergpudel.
Schlussfolgerungen und klinische Bedeutung
Diese Befunde weisen darauf hin, dass biophysische Eigenschaften wie Haut Hydratation und pH‐Wert zwischen Alter und Rasse variieren können. Diese Studie liefert wichtige Daten über die Auswirkungen von Alter, Geschlecht und Rasse auf die biophysischen Charakteristika der Hundehaut.
摘要
背景
了解皮肤的生理和生物物理特性有助于制定合适的皮肤病管理策略。然而，对于犬而言，其皮肤生物物理参数(例如年龄、性别和品种)的差异仍知之甚少。
假设/目标
本研究分析了健康犬皮肤的三个生物物理特性(水合度、pH值和皮脂含量)，并探讨了性别、年龄和品种对其的影响。
材料与方法
本研究纳入了149只无皮肤问题的犬。使用多功能皮肤生理监测仪测量其皮肤水合度、pH值和皮脂含量。将犬分为四个年龄组:<1岁、1–6岁、7–12岁和>13岁。
结果
>13岁组的皮肤水合度显著低于1–6岁组和7–12岁组。此外，>13岁组的皮肤pH值也显著低于7–12岁组。此外，对五个犬种组——比格犬(n = 37)、马耳他犬(n = 18)、迷你贵宾犬(n = 24)、可卡犬(n = 11)和博美犬(n = 12)——的皮肤生物物理参数进行分析后发现，比格犬的皮肤水分含量和pH值显著高于马耳他犬和迷你贵宾犬。
结论与临床意义
这些研究结果表明，包括皮肤水分含量和pH值在内的生物物理特性会随年龄和品种的不同而变化。本研究为年龄、性别和品种对犬皮肤生物物理特性的影响提供了基础数据。
Résumé
Contexte
La compréhension des caractéristiques physiologiques et biophysiques de la peau fournit des informations utiles pour élaborer des stratégies de prise en charge appropriées des maladies cutanées. Cependant, chez les chiens, les variations des paramètres biophysiques de la peau, telles que l'âge, le sexe et la race, restent mal comprises.
Hypothèse/objectifs
Cette étude a analysé trois caractéristiques biophysiques de la peau de chiens en bonne santé (hydratation, pH et teneur en sébum) et a examiné les effets du sexe, de l'âge et de la race.
Matériels et méthodes
Cent quarante‐neuf chiens sans problèmes cutanés ont été recrutés. L'hydratation, le pH et la teneur en sébum de la peau ont été mesurés à l'aide d'un moniteur multifonctionnel de physiologie cutanée. Les chiens ont été répartis en quatre groupes d'âge : <1 an, 1 à 6 ans, 7 à 12 ans et >13 ans.
Résultats
Les niveaux d'hydratation cutanée étaient significativement plus faibles dans le groupe >13 ans que dans les groupes 1–6 ans et 7–12 ans. De plus, les niveaux de pH cutané dans le groupe >13 ans étaient significativement plus bas que dans le groupe 7–12 ans. En outre, les paramètres biophysiques cutanés parmi les cinq groupes de races – beagles (n = 37), maltais (n = 18), caniches nains (n = 24), cockers (n = 11) et poméraniens (n = 12) – ont révélé que l'hydratation et le pH de la peau étaient significativement plus élevés chez les beagles que chez les maltais et les caniches nains.
Conclusions et pertinence clinique
Ces résultats indiquent que les propriétés biophysiques, notamment l'hydratation et le pH de la peau, varient en fonction de l'âge et de la race. Cette étude fournit des données fondamentales sur les effets de l'âge, du sexe et de la race sur les caractéristiques biophysiques de la peau des chiens.
要約
背景
皮膚の生理学的および生物物理学的特性を理解することは、皮膚疾患の適切な管理戦略を開発するための情報を提供する。しかし、犬においては、年齢、性別、犬種などによる皮膚の生物物理学的パラメーターの変動はまだ十分に理解されていない。
仮説と目的
本研究では、健常犬の皮膚の3つの生物物理学的特性(水和度、pH、皮脂量)を分析し、性別、年齢、犬種の影響を調査した。
材料と方法
皮膚疾患のない犬149頭を登録した。多機能皮膚生理モニターを用いて皮膚の水分量、pH、皮脂量を測定した。犬は4つの年齢群に分けられた: <1歳未満、1~6歳、7~12歳、13歳以上である。
結果
13歳以上の群では、1~6歳および7~12歳の群に比べ、皮膚水和レベルが有意に低かった。さらに、13歳以上群の皮膚pH値は7‐12歳群よりも有意に低かった。さらに、ビーグル(n = 37)、マルチーズ(n = 18)、ミニチュア・プードル(n = 24)、コッカー・スパニエル(n = 11)、ポメラニアン(n = 12)の5犬種グループの皮膚生物物理学的パラメータを比較したところ、ビーグルの皮膚水和度およびpHは、マルチーズとミニチュア・プードルのそれよりも有意に高いことが明らかになった。
結論と臨床的意義
これらの知見は、皮膚水和度やpHなどの生体物理学的特性が年齢や犬種によって異なることを示している。本研究は、犬の皮膚の生物物理学的特性に及ぼす年齢、性別、犬種の影響に関する基礎データを提供するものである。
Resumo
Contexto
A compreensão das características fisiológicas e biofísicas da pele fornece informações para o desenvolvimento de estratégias adequadas de manejo de doenças cutâneas. No entanto, em cães, as variações nos parâmetros biofísicos da pele, como idade, sexo e raça, ainda são pouco compreendidas.
Hipótese/objetivos
Este estudo analisou três características biofísicas da pele saudável de cães (hidratação, pH e conteúdo sebáceo) e investigou os efeitos de sexo, idade e raça.
Materiais e Métodos
Cento e quarenta e nove cães sem problemas de pele foram incluídos. A hidratação da pele, o pH e o conteúdo sebáceo foram mensurados utilizando um monitor multifuncional de fisiologia da pele. Os cães foram divididos em quatro faixas etárias: <1 ano, 1 a 6 anos, 7 a 12 anos e >13 anos.
Resultados
Os níveis de hidratação da pele foram significativamente menores no grupo >13 anos do que nos grupos de 1 a 6 anos e 7 a 12 anos. Os níveis de pH da pele no grupo >13 anos foram significativamente menores do que no grupo de 7 a 12 anos. Além disso, os parâmetros biofísicos da pele entre os cinco grupos raciais – beagles (n = 37), malteses (n = 18), poodles miniatura (n = 24), cocker spaniels (n = 11) e pomerâneos (n = 12) – revelaram que a hidratação e o pH da pele foram significativamente maiores em beagles do que em malteses e poodles miniature
Conclusões e Relevância Clínica
Esses achados indicam que as propriedades biofísicas, incluindo a hidratação e o pH da pele, variam com a idade e a raça. Este estudo fornece dados fundamentais sobre os efeitos da idade, sexo e raça nas características biofísicas da pele de cães.
RESUMEN
Introducción
Comprender las características fisiológicas y biofísicas de la piel proporciona información para desarrollar estrategias de manejo adecuadas para las enfermedades cutáneas. Sin embargo, en los perros, las variaciones en los parámetros biofísicos de la piel por factores como la edad, el sexo y la raza, siguen siendo poco conocidas.
Hipótesis/objetivos
Este estudio analizó tres características biofísicas de la piel canina sana (hidratación, pH y contenido de sebo) e investigó los efectos del sexo, la edad y la raza.
Materiales y métodos
Se incluyeron 149 perros sin problemas cutáneos. Se midieron la hidratación, el pH y el contenido de sebo de la piel mediante un monitor multifuncional de fisiología cutánea. Los perros se dividieron en cuatro grupos de edad: <1 año, 1–6 años, 7–12 años y >13 años.
Resultados
Los niveles de hidratación de la piel fueron significativamente menores en el grupo de >13 años que en los grupos de 1–6 años y de 7–12 años. Además, los niveles de pH de la piel en el grupo de >13 años fueron significativamente menores que en el grupo de 7–12 años. Más aún, los parámetros biofísicos de la piel en los cinco grupos raciales (beagles (n = 37), malteses (n = 18), caniches miniatura (n = 24), cocker spaniels (n = 11) y pomeranias (n = 12)) revelaron que la hidratación y el pH de la piel eran significativamente mayores en los beagles que en los malteses y los caniches miniatura.
Conclusiones y relevancia clínica
Estos hallazgos indican que las propiedades biofísicas, como la hidratación y el pH de la piel, varían con la edad y la raza. Este estudio proporciona datos fundamentales sobre los efectos de la edad, el sexo y la raza en las características biofísicas de la piel canina.
INTRODUCTION
The skin is a vital organ that serves as a barrier, preventing micro‐organisms and irritants from causing external chemical or physical damage. Biophysical parameters are commonly used to assess the structural and functional integrity of the skin barrier. 1 , 2 , 3 The biophysical characteristics of the skin include skin hydration, sebum content, transepidermal water loss and pH. Skin hydration, defined as the amount of water in the stratum corneum that maintains a water gradient between the skin surface and deeper epidermal layers, is maintained by natural moisturising factors (e.g. urea, lactic acid and pyrrolidone carboxylic acid) and intercellular lipids (e.g. sphingolipids and ceramides). 4 , 5 Skin pH plays a critical role in protecting the skin from invasion by micro‐organisms and in regulating the surface structure and stability of matrix lipids. 1 Sebum, a liquid composed of nonpolar lipids (e.g. triglycerides, free fatty acids, wax esters, squalene, cholesterol esters and cholesterol) secreted by the sebaceous glands, prevents excessive moisture loss, helps maintain optimal hydration levels and acts as a chemical barrier against potential pathogens. 4 , 6
In humans, skin biophysical measurements vary with age, sex, ethnicity, body site and environmental factors. 2 , 3 , 7 Skin hydration tends to decrease with age, and Caucasians exhibit higher dryness with age than Chinese individuals. 7 Additionally, skin pH tends to be higher in the elderly than in young children. 7 Sebum secretion also decreases slightly with age and is reported to be higher in males in association with higher testosterone levels. 3
In dogs, previous studies have indicated that skin hydration varies with anatomical sites and breed. 1 , 8 Dog skin pH, which is more alkaline than human skin, can vary by age, sex and anatomical sites. 1 Physiological or pathological changes caused by external substances or environmental factors can be quantified by measuring the biophysical parameters of the skin, thereby contributing to dermatological advancements in cosmetics and pharmaceuticals. 7 Therefore, understanding the physiological and biophysical characteristics of skin provides information for developing appropriate management strategies for skin diseases. This study investigated the effects of breed, sex and age on biophysical parameters using noninvasive methods.
METHODS AND MATERIALS
Animals
In order to assess skin biophysical parameters in healthy dogs based on age, sex and breed, 149 dogs without skin problems were enrolled. Dogs were enrolled that were not diagnosed with skin diseases at the time of measurement and did not have skin lesions such as erythema or scale. Additionally, to minimise underlying diseases, skin measurements were performed primarily on dogs that came to the hospital for regular medical check‐ups. Age groups were defined as: <1 year (average age 0.71 ± 0.25 years, n = 37), 1–6 years (5.03 ± 1.41, n = 44), 7–12 years (8.9 ± 1.78, n = 38) and > 13 years (14.33 ± 1.20, n = 30). Additionally, there were four sex groups consisting of female (n = 6, average age 7.10 ± 3.10 years), spayed female (n = 68, 7.6 ± 5.30), male (n = 8, 4.44 ± 3.70) and castrated male (n = 67, 6.28 ± 4.76). Breed comparisons were conducted across five groups: beagles (n = 37, average age 5.13 ± 3.39 years), cocker spaniels (n = 11, 12.56 ± 4.08), Malteses (n = 19, 4.80 ± 5.51), Pomeranians (n = 12, 6.50 ± 3.28) and miniature poodles (n = 27, 6.23 ± 5.73). All experimental procedures used in this study were approved by the Jeonbuk National University Institutional Animal Care and Use Committee (NON2024‐153‐001).
Measurement of skin biophysical parameters
In order to minimise the influence of hair on the measurements, the inguinal region, which had relatively thin hair, was selected. Assessments were performed on areas with the least hair. Skin hydration, pH and sebum levels were analysed using a multifunctional skin physiology monitor (Skin‐O‐Mat [corneometer for skin hydration, pH meter for skin pH, sebumeter for sebum]; Cosmomed GmbH). Skin hydration and pH were measured repeatedly in the same area of inguinal region. Sebum was measured in a different area of inguinal region because sebum level could have changed once absorbed by the sebumeter. Mean values were calculated for analysis. Additionally, to minimise the seasonal influence, the experiment was conducted mainly in autumn and spring (September to November and March to May).
Statistical analysis
Statistical analyses were performed using spss statistics v29 (IBM Corp.). Normality was assessed using the Shapiro–Wilk test. As the data were not normally distributed, they were analysed using the Kruskal–Wallis test with post hoc Dunnett's test. Statistical significance was set at p < 0.05. Spearman's rank correlation test was used to analyse the correlation between skin biophysical parameters. Correlation coefficients (r) of <−0.2 and >0.2 indicate weak negative and positive correlations, respectively, and r‐values <−0.4 and >0.4 indicate significant negative and positive correlations, respectively. Data were presented as medians and interquartile range (IQR).
RESULTS
Skin biophysical parameters in different age groups
Median (IQR) skin hydration levels [arbitrary units, a.u.] were 18.96 (17.57) for dogs <1 year, 24.44 (14.31) for dogs 1–6 years old, 24.26 (18.76) for dogs 7–12 years old and 15.31 (7.44) for dogs >13 years old (Figure 1a). Statistical analysis revealed that the skin hydration levels in dogs >13 years old were significantly lower than in dogs 1–6 years old (p = 0.031) and 7–12 years old (p = 0.024). Median (IQR) pH values were 6.18 (1.33) for dogs <1 year old, 6.58 (1.63) for dogs 1–6 years old, 6.55 (0.91) for dogs 7–12 years old and 5.92 (0.79) for dogs >13 years old (Figure 1b). Skin pH values in dogs >13 years old were significantly lower (more acidic) than in dogs 1–6 years old (p = 0.039). Median (IQR) sebum levels [μg/cm2] were 1 (2.5) for dogs <1 year old, 0.75 (1.88) for dogs 1–6 years old, 0.5 (0.5) for dogs 7–12 years old and 0.5 (2.38) for dogs >13 years old (Figure 1c). No significant differences in sebum levels were found between the age groups.
FIGURE 1.
Skin hydration, pH and sebum levels in different age groups. (a) Skin hydration levels in dogs aged 13 years were significantly lower than those in dogs aged 1–6 and 7–12 years. (b) Dogs aged 13 years had significantly lower (more acidic) pH levels than those aged 1–6 years. (c) Sebum levels were not statistically significant. Kruskal–Wallis test with post hoc Dunnett's test (*p < 0.05)
Skin biophysical parameters in different sex groups
Median (IQR) skin hydration levels [a.u.] were 20.92 (0.97) for intact females, 19.14 (15.53) for spayed females, 20.83 (9.43) for intact males and 22.96 (17.38) for castrated males (Figure 2a). Median (IQR) pH levels were 6.10 (0.83) for intact females, 6.18 (1.07) for spayed females, 6.53 (1.44) for intact males and 6.44 (1.37) for castrated males (Figure 2b). Median (IQR) sebum levels [μg/cm2] were 0.5 (1.88) for intact females, 1 (2.54) for spayed females, 0.25 (1.38) for intact males and 0.5 (1.25) for castrated males (Figure 2c). No significant differences in skin hydration, pH or sebum levels were observed between the sex groups.
FIGURE 2.
Skin hydration, pH and sebum levels in different sex groups. Statistical analysis revealed no significant differences in skin hydration (a), pH (b) and sebum levels (c) between the sexes. Kruskal–Wallis test with post hoc Dunnett's test.
Skin biophysical parameters in different five breeds
Median (IQR) skin hydration levels [a.u.] by breed were 29.22 (16.86) for beagles, 20.28 (8.44) for cocker spaniels, 18.06 (10.42) for Malteses, 19.448 (22.22) for Pomeranians and 14.91 (5.74) for miniature poodles (Figure 3a). Beagles had significantly higher skin hydration levels than Malteses (p = 0.023) and miniature poodles (p < 0.001). Median (IQR) pHs by breed were 6.82 (1.3) for beagles, 6.52 (0.67) for cocker spaniels, 5.94 (0.91) for Malteses, 6.375 (1.1) for Pomeranians and 5.75 (0.72) for miniature poodles (Figure 3b). In terms of pH, Beagles also showed significantly higher values than Malteses (p = 0.003) and miniature poodles (p < 0.001). Median (IQR) sebum levels [μg/cm2] by breed were 1.5 (5) for beagles, 0.5 (0.75) for cocker spaniels, 0 (1.75) for Malteses, 0.5 (1.13) for Pomeranians and 1 (4.62) for miniature poodles (Figure 3c). No significant differences in sebum levels were found between the breed groups.
FIGURE 3.
Skin hydration, pH and sebum levels in different breed groups. (a) Beagles had significantly higher skin hydration levels than Malteses (p = 0.049) and miniature poodles (p < 0.001). (b) Beagles also showed significantly higher pH than Malteses (p = 0.008) and miniature poodles (p < 0.001). (c) No significant differences were observed in sebum levels between different breed groups. Kruskal–Wallis test with post hoc Dunnett's test (*p < 0.05; **p < 0.01)
Correlations between biophysical parameters
Spearman's rho data were used to identify correlations among skin hydration, sebum and pH. A positive correlation was observed between skin hydration and pH (p < 0.001; r = 0.403) (Figure 4). No statistically significant correlations were observed between skin hydration and sebum levels or between skin pH and sebum levels (data not shown). Figure 4 shows the scatter plots of these correlations.
FIGURE 4.
Correlation between biophysical parameters (skin hydration, pH and sebum levels). A positive correlation was observed between skin hydration and pH. Spearman's rho (**p < 0.001; r = 0.403).
DISCUSSION
This study investigated skin hydration, pH and sebum levels in the inguinal region of dogs of different breeds, ages, and sexes, revealing variations in these parameters with age and breed.
In human, hydration levels decrease in infant skin and significantly decrease in the elderly, primarily as a result of a reduction in natural moisturising factors. 3 Likewise, in this study, although no statistically significant difference was observed in dogs <1 year old, median hydration levels in dogs <1 year old were lower than in the 1–6 and 7–12 year groups. Additionally, dogs >13 years old showed significantly lower skin hydration than those 1–6 years and 7–12 years old. This result aligns with a previous study reporting a decline in ceramide levels, a key factor in skin moisture retention, with aging in dogs. 9
Regarding pH, dogs >13 years old had significantly lower (more acidic) pH levels than those 1–6 years old. Although pH values in dogs 7–12 years old were higher than in dogs >13 years old, the general trend suggests that pH decreases with age, which is contrary to previous findings in humans. 7 The strong correlation between skin hydration and pH observed in this study may explain these findings. pH can vary depending on several factors, including skin hydration, atmospheric conditions, sweat secretion and the level of physical activity. 4 Unlike humans, whose skin contains eccrine glands distributed across the body, dogs predominantly have apocrine glands. Because apocrine sweat has a higher pH than eccrine sweat, it has been suggested that secretions from the apocrine glands could contribute to elevated pH levels in dogs. 10 , 11 In fact, one study found that excited dogs had higher cutaneous pH levels than nonexcited dogs and that hyperhidrosis patients exhibited a more alkaline pH than normal dogs. 10 Therefore, secretions from apocrine glands may contribute to higher skin hydration, with their components further elevating pH, leading to a strong positive correlation between hydration and pH levels.
No variance in biophysical parameters was observed between sex groups, differing from previous studies in both humans and dogs, which found higher sebum content in males. 7 In this study, most dogs were neutered; thus, the biophysical parameters of the skin were less affected by hormones. Additionally, as the number of enrolled female dogs was too small, it might be difficult to establish any significant correlation. A future study including large numbers of intact female and male dogs will provide further understanding of the skin biophysical parameters between the different sex groups.
Among the biophysical skin parameters, sebum levels are generally low, with large variations between individuals. Sebum levels measured in the inguinal area of the enrolled dogs were lower than those reported for the human leg, a low‐sebum area. 3 In humans, large variations in sebum levels occur at different anatomical sites, with lower levels in the leg and dorsal areas compared to other body sites. 3 Future studies should evaluate sebum levels at various anatomical sites.
This study evaluated skin hydration, pH and sebum content across five breeds, and observed significant breed‐related differences. Beagles exhibited relatively higher values for all three parameters. Few studies have compared the skin parameters between different breeds. In previous studies comparing beagles with large breeds, such as hounds, Labrador retrievers and fox terriers, beagles were reported to have lower skin hydration levels. 8 , 12 However, the present study observed higher skin hydration levels in beagles. Because the subjects were mainly small breeds, the observed differences might have been influenced by breed‐specific factors. Thus, further research involving a broader range of breeds is required to conduct a comprehensive comparative analysis of skin parameters.
This study has several limitations. Environmental factors such as living conditions (temperature and humidity) and bathing frequency were not fully controlled, potentially influencing the biophysical parameters. Furthermore, measurements were limited to the inguinal area, precluding determination of differences based on body area. Additionally, the relatively small sample size may limit the generalisability of the findings. Further research with large numbers of dogs is needed to investigate additional biophysical factors such as TEWL or other influencing factors, such as anatomical sites and seasonal differences.
In conclusion, the present study revealed that skin biophysical parameters of 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. These skin biophysical parameters should be considered when understanding skin diseases and developing skincare products, especially for older individuals.
AUTHOR CONTRIBUTIONS
Je‐Seong Kwon: Methodology; Investigation; Writing – original draft; Formal analysis. Eun‐Yeong Bok: Methodology; Investigation; Writing – original draft; Conceptualization. Daekyoung Kim: Investigation; Formal analysis. Chae‐Yeon Hong: Investigation. Yong‐ho Choe: Investigation; Writing – review & editing. Jaemin Kim: Formal analysis; Writing – review & editing. Tae Sung Hwang: Formal analysis; Writing – review & editing. Sung‐Lim Lee: Writing – original draft; Writing – review & editing; Conceptualization; Methodology. Ji‐Seon Yoon: Conceptualization; Investigation; Writing – original draft; Writing – review & editing; Methodology.
FUNDING INFORMATION
This study was supported by a grant from the Cooperative Research Program for Agriculture Science and Technology Development (project no. RS‐2022‐RD010282) were obtained from the National Institute of Animal Science, Rural Development Administration, Republic of Korea.
CONFLICT OF INTEREST STATEMENT
The authors declare no conflicts of interest.
ACKNOWLEDGEMENTS
We would like to thank Editage (www.editage.co.kr) for editing and reviewing this manuscript for English language.
Kwon J‐S, Bok E‐Y, Kim D, Hong C‐Y, Choe Y‐h, Kim J, et al. Variations in skin biophysical parameters with age, sex and breed in dogs. Vet Dermatol. 2025;36:689–695. 10.1111/vde.13367
Je‐Seong Kwon and Eun‐Yeong Bok shared joint first authorship.
Contributor Information
Sung‐Lim Lee, Email: sllee@gnu.ac.kr.
Ji‐Seon Yoon, Email: jiseonyoon@jbnu.ac.kr.
DATA AVAILABILITY STATEMENT
The data that support the findings of this study are available on request from the corresponding author. The data are not publicly available due to privacy or ethical restrictions.
REFERENCES
- 1. Oh W‐S, Oh T‐H. Mapping of the dog skin based on biophysical measurements. Vet Dermatol. 2010;21:367–372. [DOI] [PubMed] [Google Scholar]
- 2. Kleesz P, Darlenski R, Fluhr JW. Full‐body skin mapping for six biophysical parameters: baseline values at 16 anatomical sites in 125 human subjects. Skin Pharmacol Physiol. 2012;25:25–33. [DOI] [PubMed] [Google Scholar]
- 3. Firooz A, Sadr B, Babakoohi S, Sarraf‐Yazdy M, Fanian F, Kazerouni‐Timsar A, et al. Variation of biophysical parameters of the skin with age, gender, and body region. ScientificWorldJournal. 2012;2012:386936. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 4. Boer M, Duchnik E, Maleszka R, Marchlewicz M. Structural and biophysical characteristics of human skin in maintaining proper epidermal barrier function. Postepy Dermatol Alergol. 2016;33:1–5. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 5. Gunnarsson M, Mojumdar EH, Topgaard D, Sparr E. Extraction of natural moisturizing factor from the stratum corneum and its implication on skin molecular mobility. J Colloid Interface Sci. 2021;604:480–491. [DOI] [PubMed] [Google Scholar]
- 6. Yoon J‐S, Nishifuji K, Ishioroshi S, Ide K, Iwasaki T. Skin lipid profiling in normal and seborrhoeic shih tzu dogs. Vet Dermatol. 2013;24:84–89. e21‐2. [DOI] [PubMed] [Google Scholar]
- 7. Man MQ, Xin SJ, Song SP, Cho SY, Zhang XJ, Tu CX, et al. Variation of skin surface pH, sebum content and stratum corneum hydration with age and gender in a large Chinese population. Skin Pharmacol Physiol. 2009;22:190–199. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 8. Young LA, Dodge JC, Guest KJ, Cline JL, Kerr WW. Age, breed, sex and period effects on skin biophysical parameters for dogs fed canned dog food. J Nutr. 2002;132(S2):1695S–1697S. [DOI] [PubMed] [Google Scholar]
- 9. Yoon J‐S, Sasaki A, Shimada K, Ide K, Iwasaki T, Nishifuji K. Effects of age, sex, and breed on the composition of free extractable ceramides in the stratum corneum of healthy dogs. Vet Res Commun. 2022;46:121–126. [DOI] [PubMed] [Google Scholar]
- 10. Matousek JL, Campbell KL. A comparative review of cutaneous pH. Vet Dermatol. 2002;13:293–300. [DOI] [PubMed] [Google Scholar]
- 11. Schlake A, Devriendt N, Talloen L, Dadi TB, de Rooster H. Influence of age, sex, body condition score, rectal temperature, anatomical location and hair on skin pH in dogs. Vet Dermatol. 2022;33:3 –e2. [DOI] [PubMed] [Google Scholar]
- 12. Hester SL, Rees CA, Kennis RA, Zoran DL, Bigley KE, Wright AS, et al. Evaluation of corneometry (skin hydration) and transepidermal water‐loss measurements in two canine breeds. J Nutr. 2004;134(8 Suppl):2110S–2113S. [DOI] [PubMed] [Google Scholar]
Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.
Data Availability Statement
The data that support the findings of this study are available on request from the corresponding author. The data are not publicly available due to privacy or ethical restrictions.