Page 457 - Veterinary Toxicology, Basic and Clinical Principles, 3rd Edition

424 SECTION | V Metals and Micronutrients

VetBooks.ir 100 200 ppm dietary iodine. Puppies have been reported demineralized bone will be replaced by fibrous connective
tissue, with the facial bones often becoming enlarged
to have depressed thyroid gland function and bone abnor-
(Joyce et al., 1971), leading to the common term of big
malities when fed diets high in iodine (Castillo et al., 2001,
2003). Removal of the excess iodine from the diet, as well head disease in horses. It is also known as bran disease,
as supportive care, usually result in rapid return to normal. since feeding high dietary levels of bran, which is high in
Maximum tolerated levels of iodine in the diet vary phosphate and low in calcium, has historically been a
widely, including swine (400 ppm), chicken and turkey cause of the disease. In all animals, optimum animal per-
(300 ppm), cattle and sheep (50 ppm), horses (5 ppm) formance will be closely associated with optimum dietary
(NRC, 2005b), dogs (11 ppm), and cats (9 ppm) calcium and phosphorus balance.
(AAFCO, 2017). Phosphorus, white or yellow, has historically been
used as a rodenticide, which is uncommon today. Initial
PHOSPHORUS clinical signs following ingestion would include gastroen-
teritis with vomiting and diarrhea. If the animal survived
Most phosphorus in nature exists in combination with several days, it would often develop a secondary phase of
oxygen in the form of phosphates, primarily in igneous severe liver damage, with renal insult also occurring.
and sedimentary rocks. Inorganic phosphates are com-
monly used as chemical fertilizers and food and feed sup- REFERENCES
plements, and have many industrial uses. Phosphorus is
abundant in the animal body, primarily as a structural AAFCO, 2017. Association of American Feed Control Officials. 2017
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Anwar, R.A., Langham, R.F., Hoppert, C.A., et al., 1961. Chronic toxic-
Phosphate ions also function in acid base balance and
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other essential body functions. Phosphorus is an essential
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macroelement in nutrition, and is an important consider-
Castillo, V.A., Lalia, J.C., Junco, M., et al., 2001. Changes in thyroid func-
ation in the formulation of animal diets. The largest die-
tion in puppies fed a high iodine commercial diet. Vet. J. 161, 80 84.
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include plant-origin feeds, as well as bone, meat, poultry, cial diet. J. App. Res. Vet. Med. 1, 45 50.
and fish meals. Normal phosphorus nutrition and metabo- FDA-CVM, 2011. Target animal safety review memorandum. ,https://
lism requires adequate calcium in the diet with an appro- www.fda.gov/downloads/aboutfda/centersoffices/officeoffoods/cvm/
priate calcium-to-phosphorus ratio (Ca:P). While adverse cvmfoiaelectronicreadingroom/ucm274327.pdf. (accessed 01.03.17.).
effects of excess phosphorus are rare, they can occur with Grevatt, P.C., 1998. Toxicological Review of Hexavalent Chromium.
Support of Summary Information on the Integrated Risk
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rus levels (NRC, 2005c).
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The high dietary phosphate will depress the intestinal Talcott, P.A., Haldorson, G.J., Sathre, P., 2005. Chromium poisoning in
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