Nutritional and Metabolic Bone Dz (Pead) Flashcards
Where are 1* and 2* centres of ossification?
1 - first formation of bone eg. with long bones = the centre of the shaft
2- epiphysial growth plates
How does the skeleton of a developming aimla idffer to adult on rads?
- ^ joint space
- epiphysial growth plates not ossified
> massive roduction adn turnover for new bone formation (raw materials) - continues as an adult and calcium can act as a store of calcium
Potential presentations of nutritional/metabolic bone diesease
- young animals
- deviation of limbs, poor posture, weakness
- axial skeleton as well as appendiculr
- dietary problems
- comparison with littermates
- pathological fx (underlying causei n the bone -> weakness, no hx of trauma)
- geeralised disease
Outlien how calcium deficiency may impact musculoskeletal systems
- esential for neuromuscular function
- serum levels highly protected (for cardiac function) at the expense of bones
- Hydroxyapetite (Calcium phosphate OH) ‘robbed’ to protect serum Ca
> serum calcium NOT ALWAYS AFFECTED in calcium deficiency
What are ca levels controlled by?
- PTH stimulated with v Ca (to maintain plasma Ca)
- ^ ca absorptioin, v excretion, ^ Ca from bone
> PTH stimulates osteoblasts which stimulate osteoclasts to destroy bone
How may 2* hyerpaathyroidism be seen on rads?
- path fx
- less of a difference between cortex and medulla
Causes of 2* nutritional hyperparathyroidism ? Pathogenesis?
- v dietary calcium
- ^ dietary phosphate
- ^ PTH
- serum calcium often protected
- bones malformed/poorly formed
- usually only see in growing animals (v unusual for dietary ca to be too low in adults)
Tx hyperparathyroiism with path fx in the young animal?
- excercise restriction
- Ca controlled diet
When are calcium deficiencies commonly seen?
- exotics
- pets usually fed commercial diet (will be balanced)
Where is active vit D sythesised? Actions?
- Kidney
- Ca release
- ^ absorption in the GIT
- v excretion
Is Vit D deficiency common in animals? How does this manifest young animals and adults?
- very rare on its own
> Ca, Vit D and UV light combination diseases more common - Juvenile - Rickets
- Adult - Osteopenia
Which animals are predisposed to vit D/Calcium/UV light diseases?
- iguanas and chelonians
- called “metabolic bone disease” as pathophysiology not fully known
- v activation of vit D3
- v phosphate excretion (phosphate binds calcium, serum clacium lowered)
- ^ PTH drive -> bone problems
- low dietary availablility of calcium and decresed activation/availablitiy of vit D
Presentation/history of metabolic bone disease in reptiles? DXX?
> Hx: lethargy
PE: activity movement/lameness/joint swelling, limb swelling, muscle atrophy
Rads: joints limbs and spine, egg binding, spontaneous fx
BLoods: Low Ca
Ddx for metabolic bone diease in reptiles?
- gout (deposition of urate crystals)
- septic arthritis
- spinal spondylosis
> confirmation: - swollen bones, poor density
- low serum Ca (tail v)
Tx metabolic bone disease?
- ca gluconate
- dietary adjustment (2% Ca diet)
- UV light or direct sunlight
- monitor blood Ca
