Exotics 2 - Aimee Flashcards
What are the features of metabolic bone disease?
- Rickets
- Osteomalacia
- Fibrous osteodystrophy
Describe the etiology of MBD
Multifactorial
- Absolute calcium deficiency
- Ca:P imbalance
- Vitamin D deficiency
What is rickets?
Inadequate mineralization of bone due to deficiencies in vitamin D and or calcium
What is osteomalacia?
Softening of bone due to mineral loss from a previously mineralized bone.
Which age group is usually affected by osteomalacia?
Adults
What is fibrous osteodystrophy?
Replacement of bone with fibrous material.
Fibrous osteodystrophy is a common feature of which disease and which condition?
Metabolic bone disease
Nutritional secondary hyperparathyroidism (condition)
How is vitamin D metabolized?
- Sunlight exposure is absorbed by the skin.
- The skin synthesizes vitamin D3 (cholecalciferol).
- Vitamin D3 is processed in the liver to calcidiol.
- The kidney transforms the calcidiol into calcitriol which is the active form of vitamin D3.
What are the target organs of vitamin D?
- Intestines: Enhances calcium and phosphate absorption.
- Bone: Promotes bone mineralization.
- Parathyroid glands: Regulates parathyroid hormone production.
Which form of vitamin D is required by new world primates, birds, reptiles, and fish require?
D3, they cannot use D2.
Which species are unable to ingest adequate vitamin D through their diet?
Most reptiles cannot and require adequate sunlight/UVB exposure.
What form of vitamin D is used by mammals?
Most mammals can use D2 and D3
What are common clinical signs of metabolic bone disease (MBD) in young animals?
- Lameness
- Bone deformities
- Fractures and softening of bone
- Swollen jaws and tooth loss
- Hypocalcemic tetany
What additional signs of MBD are specific to reptiles?
Signs in reptiles include deformed shells (in turtles) and paralysis (especially in lizards).
What additional signs of MBD are specific to birds?
Signs in birds include poor feathering and deformed/soft eggs.
What additional signs of MBD are specific to primates?
Reluctance to climb.
In which animal groups is MBD most common?
MBD is most common in young carnivores, birds, and reptiles.
What caution should be taken during a physical exam of an animal with severe MBD?
In severe cases of MBD, the jaw can fracture during a physical exam if the mouth is opened with significant force.
What are some clinical signs of metabolic bone disease (MBD) in animals that can lead to diagnosis?
Facial and long bone swelling, especially in primates and carnivores. Osteodystrophy.
What can diagnostic imaging reveal in cases of MBD?
Radiographs showing reduced bone density and cortical thinning.
What blood tests are relevant for diagnosing MBD?
Total serum calcium levels, ionized calcium, and plasma vitamin D levels (may be extremely low).
What may happen in severe cases of MBD regarding X-ray visibility?
Long bones and pelvis may not be visible on X-ray, which could lead to consideration of euthanasia.
How is MBD diagnosed?
- History and physical exam
- Diagnostic imaging
- Bloodwork
Describe vitamin D requirements in birds.
No dietary requirement if they receive adequate sunlight.
Their uropygial gland contains vitamin D3 precursors that are activated by the sun.