En bref

Metabolic Bone Disease (MBD), or nutritional secondary hyperparathyroidism, is a common and serious condition in captive reptiles and turtles. Caused by a lack of dietary calcium, improper calcium-to-phosphorus ratios, or insufficient UVB light, it leads to weak, deformed bones and muscle tremors. Learn how to recognize the signs, how veterinarians diagnose and treat it, and how proper husbandry can prevent this debilitating disease.

TL;DR. Affection évitable chez reptiles et tortues par manque de calcium ou d'UVB: os mous, déformations et tremblements.

Les UVB sont essentiels pour synthétiser la vitamine D3 et absorber le calcium.

Qu'est-ce que c'est ?

Metabolic bone disease in captive reptiles/turtles is usually nutritional secondary hyperparathyroidism: insufficient calcium or UVB leads to soft bones, fibrous reinforcement of limbs/jaws, and muscle tremors. Calcium is pulled from bone to keep blood calcium safe.

Causes et facteurs de risque

Husbandry errors: inadequate UVB (290-315 nm), low dietary calcium, poor Ca:P ratio (aim near 2:1), cold enclosures. Fast-growing species are highest risk.

Signes à surveiller

Rubber jaw; soft/warped shell in chelonians (cardinal)
Swollen firm limbs, pathological fractures, lethargy, anorexia, tremors (common)
Paresis/paralysis from spinal deformity (occasional)

A bearded dragon showing a shortened lower jaw and swollen rear legs.
Mâchoire raccourcie et membres gonflés sont des signes avancés classiques.

Comment les vétérinaires diagnostiquent

Husbandry review. Radiographs (gold): demineralized ghost bones, hidden fractures. Ionized calcium; biochemistry for kidney and phosphorus.

$An X-ray of a lizard showing thin, demineralized bones and a femur fracture.$
Les radios montrent os déminéralisés et fractures occultes.

Options de traitement

Oral or injectable calcium salts; phosphate binders if phosphorus high; cautious calcitriol after calcium stabilizes. Fix UVB, heat gradient, diet.

Pronostic

Excellent if early before severe deformity. Permanent shape changes may remain. Poor with paralysis or severe kidney disease.

Prévention

Linear UVB (replace every 6-12 months), calcium (± D3 indoors), gut-load insects, Ca-rich greens, correct thermal gradient.

Quand appeler le vétérinaire

Emergency: continuous tremors/seizures, inability to lift body, soft jaw/shell, visible fractures, extreme lethargy or prolonged anorexia.

Sources

Mader's Reptile and Amphibian Medicine and Surgery, 3rd Edition, pages 315-321, 811-814.
BSAVA Manual of Reptiles, 3rd Edition, pages 102-105, 210-212.

My highlights & notes

Questions fréquentes

What is Metabolic Bone Disease?

What are the symptoms of Metabolic Bone Disease?

Soft, deformed carapace or plastron、Soft, pliable mandible or maxilla (rubber jaw)、Loss of appetite、Lethargy and weakness、Muscle tremors or twitching、Pathological fractures、Swollen, firm limbs、Paresis or paralysis

How is Metabolic Bone Disease diagnosed?

Radiography、Plasma Biochemistry Panel、Plasma Ionized Calcium

How is Metabolic Bone Disease treated?

Le traitement doit être prescrit par un vétérinaire agréé selon votre animal. Les doses précises ne sont volontairement pas affichées.

Cet article est informatif et ne remplace pas un avis vétérinaire. Si votre animal est malade, consultez un vétérinaire.

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Metabolic Bone Disease