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Endocrine & Nutritional Influences on the Skin (view source)
Revision as of 15:53, 23 July 2008
, 15:53, 23 July 2008New page: <big><center>'''BACK TO INTEGUMENTARY - ANATOMY & PHYSIOLOGY'''</center></big> ==Endocrinology of the Skin== There are various hormones that may i...
<big><center>[[Integumentary - Anatomy & Physiology|'''BACK TO INTEGUMENTARY - ANATOMY & PHYSIOLOGY''']]</center></big>
==Endocrinology of the Skin==
There are various hormones that may infulence the structure of the skin. These influences may be made apparent by the repeated long-term administration of various glucocorticoids or their analogues. Endogenous imbalances are generally seen in adult mature animals although congenital forms have been seen, especially with [[Endocrine System - Thyroid Gland - Anatomy & Physiology#Problems associated with the Thyroid Gland|hypothyroidism]]. The hormones implicated as important for maintaining skin structure are '''thyroxine, cortisol''' and '''estradiol'''. Deficiencies or excessive production may result from abberations in the function of the [[Endocrine System - Adrenal Glands - Anatomy & Physiology|hypothalamic-adrenal axis]], the '''adrenal gland, thyroid gland''' and the '''gonads'''.
Cutaneous changes may include [[Hair - Anatomy & Physiology#Hair Types|telogen]] hair follicles leading to [[Skin - glossary|alopecia]], epidermal and dermal thinning, atrophy of [[Skin - Anatomy & Physiology#Glands|sebaceous glands]] and the [[Hair - Anatomy & Physiology|arrector pili]] muscles. There may also be an increased risk of microbial infection due to poor immune surveillance and delayed wound healing. There are significant differences between species in the manifestation of symptoms.
==Nutrition and the Skin==
Most animals are fed balanced diets and are therefore unlikely to exhibit symptoms when in veterinary care. There are some systemic conditions that can reflect deficiency as a result of hepatic or gut diseases for example.
Malnutrition whether due to a deficiency of protein or other nutrients or secondary to a debilitating condition may lead to a dull, brittle and thin haircoat and to dry, scaly skin. This in part reflects the high requirement for dietary amino acids to supply requisite building blocks for epidermal turnover and hair growth. Sulfur-containing amino acids are common in the skin and therefore sulfur supplementation is popular for dealing with skin conditions.
===Trace Elements===
Trace elements such as '''copper''' are rarely deficient in farm animals, although deficiency can be associated with poor fertility, ill-thrift and leukotrichia - leading to perioccular 'spectacles'. This reflects the role of copper in the formation of [[Skin - Anatomy & Physiology#Cells of the Epidermis|melanin]].
Excessive exposure to trace elements can also have harmful effects and again, although rare, examples may include '''selenosis''' which is usually seen as [[Skin - glossary|alopecia]] in geographical areas with high '''selenium''' soil content for grazing animals.
===Vitamins===
*'''Vitamin A''' has a variety of roles that may infulence skin and coat condition. Some conditions may respond to supplementation with vitamin A or zinc, but this may not necessarily reflect a deficiency in the diet.
*'''Vitamin C''' deficiency may be associated with '''scurvy''' in guinea pigs. The impact of various disease processes that influence feed intake may lead to poor quality coat and skin condition.
*'''Vitamin D''' is processed in part in the skin.
==Endocrinology of the Skin==
There are various hormones that may infulence the structure of the skin. These influences may be made apparent by the repeated long-term administration of various glucocorticoids or their analogues. Endogenous imbalances are generally seen in adult mature animals although congenital forms have been seen, especially with [[Endocrine System - Thyroid Gland - Anatomy & Physiology#Problems associated with the Thyroid Gland|hypothyroidism]]. The hormones implicated as important for maintaining skin structure are '''thyroxine, cortisol''' and '''estradiol'''. Deficiencies or excessive production may result from abberations in the function of the [[Endocrine System - Adrenal Glands - Anatomy & Physiology|hypothalamic-adrenal axis]], the '''adrenal gland, thyroid gland''' and the '''gonads'''.
Cutaneous changes may include [[Hair - Anatomy & Physiology#Hair Types|telogen]] hair follicles leading to [[Skin - glossary|alopecia]], epidermal and dermal thinning, atrophy of [[Skin - Anatomy & Physiology#Glands|sebaceous glands]] and the [[Hair - Anatomy & Physiology|arrector pili]] muscles. There may also be an increased risk of microbial infection due to poor immune surveillance and delayed wound healing. There are significant differences between species in the manifestation of symptoms.
==Nutrition and the Skin==
Most animals are fed balanced diets and are therefore unlikely to exhibit symptoms when in veterinary care. There are some systemic conditions that can reflect deficiency as a result of hepatic or gut diseases for example.
Malnutrition whether due to a deficiency of protein or other nutrients or secondary to a debilitating condition may lead to a dull, brittle and thin haircoat and to dry, scaly skin. This in part reflects the high requirement for dietary amino acids to supply requisite building blocks for epidermal turnover and hair growth. Sulfur-containing amino acids are common in the skin and therefore sulfur supplementation is popular for dealing with skin conditions.
===Trace Elements===
Trace elements such as '''copper''' are rarely deficient in farm animals, although deficiency can be associated with poor fertility, ill-thrift and leukotrichia - leading to perioccular 'spectacles'. This reflects the role of copper in the formation of [[Skin - Anatomy & Physiology#Cells of the Epidermis|melanin]].
Excessive exposure to trace elements can also have harmful effects and again, although rare, examples may include '''selenosis''' which is usually seen as [[Skin - glossary|alopecia]] in geographical areas with high '''selenium''' soil content for grazing animals.
===Vitamins===
*'''Vitamin A''' has a variety of roles that may infulence skin and coat condition. Some conditions may respond to supplementation with vitamin A or zinc, but this may not necessarily reflect a deficiency in the diet.
*'''Vitamin C''' deficiency may be associated with '''scurvy''' in guinea pigs. The impact of various disease processes that influence feed intake may lead to poor quality coat and skin condition.
*'''Vitamin D''' is processed in part in the skin.