Nutritional and Metabolic Bone Dz (Pead) Flashcards Preview

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Flashcards in Nutritional and Metabolic Bone Dz (Pead) Deck (20):

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


When is 2* renal hyperparathyroidism seen?

- CKD (usually adults)
- v activation of vit D
- v phosphate excretion (phosphate binds calcum -> v serum calcium)


Where is renal hyperparathyrid commonly manifested?

Mandible becomes soft and pliable


How can hormones mipact musculoskeletal system?

- loss of oestrogen pulses -> post-menopausal osteoporosis
> problem NOT seen in spayed bitches (bne loss for ~12 weeks then recover)


Which diseases are often called "metabolic" bone dz?

*termed this as hard to classify*
> calcinosis circumscrimpta
- response to injury?
- deposition of calium around joints
> craniomandibular osteopathy
- immune mediated
> metaphyseal osteopathy
- pain and fever concurrently
= hyertrophic osteodystrophy (HOD)
- associated w/ distemper
- transeint ~ 1 wweek
- Tx symptomatically (analgesia and IVFT)
> Panosteitis
- growing animals
- inflam endostium -> laying down of new bone
- growing pains, self limiting but painful on palp
> hypertrophic pulmonary osteoarthropathy (Marie's dz)
- distal limb periosteal activation d/t thoracic/abdo tumour secreting growth factors


How ae long bones formed?

Endochondral ossification