Osteomalacia and fibrous osteodystrophy

OSTEOMALACIA AND FIBROUS OSTEODYSTROPHY

  • These disorders are often seen in the young hatchlings of crocodiles which subsequently reveal failure of hardening of bones due to lack of calcium.
  • Among mammals, bone eaters (eg. hyaena) if deprived of bones during feeding (like hyaenas) will end up in metabolic bone diseases.

Etiology

  • Feeding diet with less calcium (provision of mince with liver and heart without bone or with less bones)
  • Failure in proper absorption of calcium (diseases of GI tract / excessive phosphorus in diet)
  • Insufficient calcium supplement and hormonal imbalances due to multiple causes
  • Lack of vitamin D esp. in indoor-kept wild animals.
  • Prolonged storage of ration leads to less vitamin D3

Clinical signs

  • Crocodiles get often affected by the metabolic bone diseases. The signs are :
    • Persisting of kyphokoliosis ( hunch backed appearance) esp. in subadults and adult crocodiles
    • Weakness of hatchling to walk on land while they still can move freely if in water or can swim freely in water.
    • Falling of teeth and poor calcification of teeth
    • Jaw bones become more pliable as evidenced in case of hatchlings(rubber jaws)
    • Weakness in hatchlings along with sluggish movements
    • Teeth becomes diaphanous like shards of glass (glassy teeth)
    • In chelonians, lump like appearance of carapace(compare with normal nearby chelonian)

Diagnosis

  • Serum estimation of calcium and phosphorus in addition to the radiographical examination and clinical signs and history of feeding and management

Note

  • In this context, it is to be remembered that especially in the periods of production of egg shells, the calcium mobilization from bones is at peak and hence, the reptiles when hypocalcemic during these periods will have difficulties in maintaining muscular tonicity and as a result, prolapse of uterus may occur in crocodiles.
  • Hence, whenever prolapse occurs in crocodiles or any reptiles, correlation with the metabolic derangements of calcium need to be paid attention.
Last modified: Friday, 27 April 2012, 9:56 AM