It was interesting to hear Doug Mader at BSAVA 2010 saying forcibly that the term Metabolic Bone Disease (MBD) shouldn't be used - its too much of a catch-all, it can be 'qualified' as Nutritional MBD or refer to Nutritional Secondary Hyperparathyrodism (NSHP).
NSHP is still depressingly common, affected animals being dull and lethargic, with a decreased appetite - often because of the effort required to get to the plate or to eat!
Activity is usually reduced, often to the point that the hindlimbs barely move and muscles may be atrophied. The animals appear closer to the ground and may present with 'spontaneous' fractures. Tetany may also be seen. In females the onset of egg laying may precipitate the appearance of signs, despite the eggs being normally soft-shelled .
Undermineralisation is relatively obvious on radiography and blood calcium levels will be reduced.
Treatment of acute hypocalcaemia involves rapid correction of the blood levels using calcium gluconate or Zolcal D. Repeated doses may be required to achieve remission of signs.
Dietary calcium levels need correction with high calcium supplements eg. Nutrobal (Vetark). It is often necessary to exceed the standard rate of 0.1g/kg per day over a period of 6-8 weeks or until the problem is corrected.
Monitoring of serum calcium levels is advisable. Radiography to monitor progress is also valuable.
Treatment of associated fractures depends on the level of undermineralisation of the bone; severely undermineralised bone needs prior supplementation before intramedullary fixation is used. In the interim, external supports eg. Hexcelite (Hexcel) fitted like a jacket may be useful. It will take MONTHS to achieve healing.