Changes

[[Image:Renal_osteodystrophy.jpg|thumb|right|200px|"Rubber jaw" in renal osteodystrophy. Image courtesy of Biomed Archive.]]

[[Image:Renal_osteodystrophy.jpg|thumb|right|200px|"Rubber jaw" in renal osteodystrophy. Image courtesy of Biomed Archive.]]

[[Image:parathyroidhyperplasia.jpg|thumb|right|200px|Parathyroid hyperplasia. Image courtesy of Biomed Archive.]]

[[Image:parathyroidhyperplasia.jpg|thumb|right|200px|Parathyroid hyperplasia. Image courtesy of Biomed Archive.]]

Hyperparathyroidism is an '''[[Endocrine System - Anatomy & Physiology|endocrine]] disease''' caused by overactivity of the [[Parathyroid Glands - Anatomy & Physiology|parathyroid gland]] and consequent '''raised body levels of [[Calcium#Parathyroid Hormone|parathyroid hormone (PTH)]]'''. It occurs in many veterinary species and can be primary or secondary.  

Hyperparathyroidism is an '''[[Endocrine System - Anatomy & Physiology|endocrine]] disease''' caused by overactivity of the [[Parathyroid Glands - Anatomy & Physiology|parathyroid gland]] and consequent '''raised body levels of [[Calcium#Parathyroid Hormone|parathyroid hormone (PTH)]]'''. This in turn results in chronic hypercalaemia. It occurs in many veterinary species and can be primary or secondary.  

 

<big>'''Primary hyperparathyroidism'''</big> originates within the parathyroid gland itself and can be due to '''glandular hyperplasia or [[Neoplasia - Pathology|neoplasia]]'''. It is most commonly due to a '''solitary benign [[Adenoma|adenoma]]''' of either the [[Parathyroid Glands - Anatomy & Physiology|internal or external parathyroid gland]].<ref>Merck Veterinary Manual, '''Primary Hyperparathyroidism''', accessed online 25/07/2011 at http://www.merckvetmanual.com/mvm/index.jsp?cfile=htm/bc/40407.htm</ref>

<big>'''Primary hyperparathyroidism'''</big> originates within the parathyroid gland itself and can be due to '''glandular hyperplasia or [[Neoplasia - Pathology|neoplasia]]'''. It is most commonly due to a '''solitary benign [[Adenoma|adenoma]]''' of either the [[Parathyroid Glands - Anatomy & Physiology|internal or external parathyroid gland]].<ref>Merck Veterinary Manual, '''Primary Hyperparathyroidism''', accessed online 25/07/2011 at http://www.merckvetmanual.com/mvm/index.jsp?cfile=htm/bc/40407.htm</ref>

Secondary '''renal hyperparathyroidism''' is a complication of '''chronic renal failure'''. This is due to '''hyperphosphataemia developing as a result of impaired glomerular filtration rate'''. '''Reduced vitamin D''' synthesis is also thought to contribute to low serum calcium levels and subsequent stimulation of the parathyroid gland. Renal production of [[Calcium#Calcitriol|calcitriol]] is also reduced, exacerbating the resulting [[hypercalcaemia]].  

 

Secondary '''renal hyperparathyroidism''' is a complication of '''chronic renal failure'''. This is due to relative '''hyperphosphataemia developing as a result of impaired glomerular filtration rate'''. '''Reduced vitamin D''' synthesis or absorbtion is also thought to contribute to low serum calcium levels and subsequent stimulation of the parathyroid gland. Renal production of [[Calcium#Calcitriol|calcitriol]] (active Vitamin D3) is also reduced, exacerbating the resulting [[hypercalcaemia]].  

Secondary '''nutritional''' hyperparathyroidism is caused by excessive '''phosphorus intake''' causing a total or relative calcium deficiency by '''binding calcium in the gut and decreasing its absorption'''.  This category encompasses '''bran disease in horses and also [[Metabolic Bone Disease|metabolic bone disease]] in reptiles'''.

Secondary '''nutritional''' hyperparathyroidism is caused by excessive '''phosphorus intake''' causing a total or relative calcium deficiency by '''binding calcium in the gut and decreasing its absorption'''.  This category encompasses '''bran disease in horses and also [[Metabolic Bone Disease|metabolic bone disease]] in reptiles'''.