Nutritional or Metabolic Bone Disease Flashcards
What is the process of endochondral ossification?
Cartilage proliferates and mineralises
Bone starts to form from the middle of the bone working its way outwards
Buds also form at epiphyses leaving physis
What is the name through which bones form?
Endochondral ossification
What do radiographs of young animal bones typically look like?
Apparently large gaps in joints due to cartilage being present instead of bone
Floating mineralised areas = apophyses
How does bone turnover differ in adulthood compared to juveniles?
Slower rate
When does bone disease present?
Often young animals but can be in adults
What does bone disease present as clincally?
Deviation of limbs, poor posture, weakness
Axial skeleton and appendices affected
Pathological fractures due to folding of bones
What is a common cause of bone disease in young animals?
Dietary problems due to poor intake of calcium
Why does calcium metabolism result in bone deformities in calcium deficient juveniles?
Calcium is essential for neuromuscular function so serum calcium levels are highly protected
Bone is a store of calcium so it is taken from them due to PTH and Vit D3 in order to maintain serum calcium levels
What is the pathogenesis of secondary nutritional hyperthyroidism?
Low dietary calcium results in increased PTH = increased osteolysis and decreased osteoproliferation
Serum calcium levels protected at the expense of the bones which become malformed or poorly formed
Often a problem in growing animals
In which animals can vitamin D deficiency occur in and what does it cause?
Dogs
Juveniles = rickets
Adults = osteopaenia
What is the pathogenesis of secondary renal hyperparathyroidism?
Chronic renal failure in adults with decreased activation of vitamin D3 and lowered phosphate excretion
Phosphate binds to calcium lowering serum calcium levels
Lowered serum calcium increases PTH and its effects on bones
What is thought to cause metabolic bone disease of reptiles and chelenians?
Low dietary calcium and decreased activation or availability of vitamin D3
What are the clinical signs of reptilian metabolic bone disease?
Lethargy, inability to lift trunk or tail, pliant mandible, abnormal posture, weight loss/decreased appetite
On clinical exam = joint swelling, limb swelling, muscular tone and atrophy
How do you diagnose reptilian metabolic bone disease?
Radiograph joints, limbs and spine, look for egg binding and spontaneous fractures
Blood sample for low serum calcium
Swollen bones with poor density, misshapen pliant mandible, lethargy, inability to lift body, pathological fractures and low serum Ca
What is the treatment for reptilian metabolic bone disease?
Calcium gluconate
2% Ca diet
UV light and/or direst sunlight
Monitor blood Ca
