Introduction

• Literally means abnormal growth of cartilage and results in disproportionate dwarfism.
• Cause: genetic cartilage abnormality.
• Several dog breeds display this as standard conformation, eg Dachshund, Bassett hound.
• Signs: limb shortening + flared metaphyses, depressed nasal bridge + shortened maxilla → crowding of teeth.
• Diagnosis: clinical signs.
• Treatment: none.
• Prognosis: may be normal, or guarded if congenital defect.

Pathogenesis

Pathophysiology

• Abnormal interstitial growth of physeal cartilage → generalized shortening of the bones which develop by endochondral ossification:
  • Limbs.
  • Ribs.
  • Vertebral column.
• Early growth arrest of some bones which make up the cranium → enlarged dome-shaped skull due to continued brain growth.
• Hypoplasia of base of cranium, ethmoids and turbinates → flattened face → normal sized tongue then protrudes beyond jaw.

Diagnosis

Treatment

Outcomes