Changes

==Why is it Important?==

==Why is it Important?==

Zinc has many essential functions in the body, it is a co-factor or catalyst in at least 200 zinc-containing enzymes that are involved in protein, carbohydrate, nucleic acid and lipid metabolism<ref>Valee, BL, Falchuk, KH (1993). “The biochemical basis of zinc physiology”. Physiol. Rev. 73:79-118.</ref>.   

Zinc has many essential functions in the body, it is a co-factor or catalyst in at least 200 zinc-containing enzymes that are involved in [[Digestibility of Protein|protein]], [[Digestibility of Carbohydrate|carbohydrate]], nucleic acid and [[Digestibility of Fat|lipid]] metabolism<ref>Valee, BL, Falchuk, KH (1993). “The biochemical basis of zinc physiology”. Physiol. Rev. 73:79-118.</ref>.   

==Roles in the Body==

==Roles in the Body==

Zinc plays a '''crucial role in skin function and wound healing, cell replication, the structure and function of biological membranes as well as the  stabilisation of the nucleic acids'''. It is absorbed mainly in the [[:Category:Small Intestine - Anatomy & Physiology|small intestine]], the highest rates occurring in the jejunum. '''Various dietary factors affect the absorption of zinc, in particular high intakes of calcium, [[Iron - Nutrition|iron]] and phytate''', all of which reduce its availability<ref>“Zinc” In: Mineral Tolerance of Animals, 2nd Edition. (2005) National Research Council, National Academy of Sciences. The National Academies Press, Washington DC: p 414.</ref>.   

Zinc plays a '''crucial role in skin function and wound healing, cell replication, the structure and function of biological membranes as well as the  stabilisation of the nucleic acids'''. It is absorbed mainly in the [[:Category:Small Intestine - Anatomy & Physiology|small intestine]], the highest rates occurring in the [[Jejunum - Anatomy & Physiology|jejunum]]. '''Various dietary factors affect the absorption of zinc, in particular high intakes of [[Calcium - Nutrition|calcium]], [[Iron - Nutrition|iron]] and phytate''', all of which reduce its availability<ref>“Zinc” In: Mineral Tolerance of Animals, 2nd Edition. (2005) National Research Council, National Academy of Sciences. The National Academies Press, Washington DC: p 414.</ref>.   

==Consequences of Zinc Deficiency==

==Consequences of Zinc Deficiency==

===Dog:===   

===Dog:===   

'''Zinc is of relatively low toxicity in dogs'''. In fact some studies have shown beneficial effects of zinc at concentrations higher than the accepted nutritional requirement. Marsh et al.<ref>Marsh, KA, Ruedisueli, FL, Coe, SL, Watson, TDG (2000). “Effects of zinc and linoleic acid supplementation on the skin and coat quality of dogs receiving a complete and balanced diet”. Vet. Dermatol. 11:277-284.</ref> reported that feeding a complete and balanced diet containing higher than normal levels of zinc (400 mg/kg DM) and linoleic acid (6% DM) to black Labrador retrievers for 9 weeks was associated with significant improvements in coat condition. Dogs fed the high zinc level on its own showed a significant decrease in transepidermal water loss.  

'''Zinc is of relatively low toxicity in dogs'''. In fact some studies have shown beneficial effects of zinc at concentrations higher than the accepted nutritional requirement. Marsh et al.<ref>Marsh, KA, Ruedisueli, FL, Coe, SL, Watson, TDG (2000). “Effects of zinc and linoleic acid supplementation on the skin and coat quality of dogs receiving a complete and balanced diet”. Vet. Dermatol. 11:277-284.</ref> reported that feeding a complete and balanced diet containing higher than normal levels of zinc (400 mg/kg DM) and linoleic acid (6% DM) to black Labrador retrievers for 9 weeks was associated with significant improvements in coat condition. Dogs fed the high zinc level on its own showed a significant decrease in transepidermal water loss.  

Therapeutic doses of zinc of about 20 mg/kg bodyweight/day (equivalent to a dietary zinc concentration of approximately 1100 mg/kg DM for a Bedlington terrier weighing 9 kg), have been given to certain dog breeds such as the Bedlington terrier, Labrador retriever, West Highland white terrier and Dobermann pinscher, which have an inherited defect that results in toxic excesses of copper in the liver, causing hepatitis and cirrhosis. Zinc supplementation is continued for 2 to 3 months, followed by halving the dose thereafter to block copper absorption and decrease copper accumulation in the liver<ref>Brewer, G, Dick, R, Schall, W, Yuzbasiyan-Gurkan, V, Mullaney, T, Pace, C, Lindgren, J, Thomas, M, Padgett, G (1992). “Use of zinc acetate to treat copper toxicosis in dogs”. J. Am. Vet. Med. Assoc.  210:564-568.</ref><ref>Hoffmann, G, Jones, PG, Biourge, V, van den Ingh, TSGAM, Mesu, SJ, Bode, P, Rothuizen, J (2009). “Dietary management of hepatic copper accumulation in Labrador retrievers”. J. Vet. Int. Med. 23:957-963.</ref> [WikiVet Link to Copper].

Therapeutic doses of zinc of about 20 mg/kg bodyweight/day (equivalent to a dietary zinc concentration of approximately 1100 mg/kg DM for a Bedlington terrier weighing 9 kg), have been given to certain dog breeds such as the Bedlington terrier, Labrador retriever, West Highland white terrier and Dobermann pinscher, which have an inherited defect that results in toxic excesses of [[Copper - Nutrition|copper]] in the [[Liver - Anatomy & Physiology|liver]], causing [[Hepatitis, Chronic|hepatitis]] and [[cirrhosis]]. Zinc supplementation is continued for 2 to 3 months, followed by halving the dose thereafter to block copper absorption and decrease copper accumulation in the liver<ref>Brewer, G, Dick, R, Schall, W, Yuzbasiyan-Gurkan, V, Mullaney, T, Pace, C, Lindgren, J, Thomas, M, Padgett, G (1992). “Use of zinc acetate to treat copper toxicosis in dogs”. J. Am. Vet. Med. Assoc.  210:564-568.</ref><ref>Hoffmann, G, Jones, PG, Biourge, V, van den Ingh, TSGAM, Mesu, SJ, Bode, P, Rothuizen, J (2009). “Dietary management of hepatic copper accumulation in Labrador retrievers”. J. Vet. Int. Med. 23:957-963.</ref> [WikiVet Link to Copper].

===Cat:===   

===Cat:===   

Sterman et al.<ref>Sterman, M, Shouse, M, Fairchild, M, Belsito, O (1986). “Kindled seizure induction alters and is altered by zinc absorption”. Brain Res. 383:382-386.</ref> fed adult cats a dietary zinc content of 600 mg/kg DM for 6 weeks with no apparent adverse effects, although the blood zinc concentration increased compared with control cats fed a zinc level of 100 mg/kg DM. '''This suggests that, like the dog, cats can tolerate zinc concentrations well above the nutritional requirement'''.

Sterman et al.<ref>Sterman, M, Shouse, M, Fairchild, M, Belsito, O (1986). “Kindled seizure induction alters and is altered by zinc absorption”. Brain Res. 383:382-386.</ref> fed adult cats a dietary zinc content of 600 mg/kg DM for 6 weeks with no apparent adverse effects, although the blood zinc concentration increased compared with control cats fed a zinc level of 100 mg/kg DM. '''This suggests that, like the dog, cats can tolerate zinc concentrations well above the nutritional requirement'''.

==Dietary Sources==

==Dietary Sources==

Zinc is fairly well distributed in raw materials used in dog and cat foods. Animal sources, such as red meats, fish meals and meat meals contain the highest amounts but cereal grains and in particular soybean, peanut and linseed meals also contain reasonable quantities. Nevertheless, to ensure nutritional adequacy most dog and cat foods are supplemented with zinc salts such as the chloride, carbonate, sulphate, lactate or acetate.

Zinc is fairly well distributed in raw materials used in dog and cat foods. Animal sources, such as red meats, fish meals and meat meals contain the highest amounts but cereal grains and in particular soybean, peanut and linseed meals also contain reasonable quantities. Nevertheless, to ensure nutritional adequacy most dog and cat foods are supplemented with zinc salts such as the [[Chloride - Nutrition|chloride]], carbonate, sulphate, lactate or acetate.

==References==

==References==

[[Category:To Do - Nutrition]]

[[Category:To Do - Nutrition]]

[[Category:To Do - Nutrition GGP]]

[[Category:To Do - Nutrition preMars]]