Bones 4

• what are the causes of osteonecrosis 


  1. fracture with vascular compromise
  2. acute inflammation
  3. infiltrating neoplasms
  4. thromboembolism
  5. peripheral vasoconstriction
• what is a large fragment of necrotic bone called

  A sequestrum
• pathogenesis of legg-clave perthes disease and breeds affected 


  it is manifested as avascular necrosis of femoral head , occurs in small breeds eg miniature poodles , west highland white and yorkshire terriers
• Which dog breeds are typically affected by Legg-Calvé-Perthes disease?

  Highland white and Yorkshire terriers
• At what age does Legg-Calvé-Perthes disease typically occur in affected pups?

  4 to 8 months of age
• How does Legg-Calvé-Perthes disease typically present in terms of laterality?

  It can sometimes be bilateral
• What is the pathogenesis of Legg-Calvé-Perthes disease related to blood vessels?

  Blood vessels to the femoral head travel along the femoral neck before entering the bone
• What happens to the blood vessels in susceptible breeds regarding their position?

  The vessels remain superficial
• What may impair venous drainage in susceptible breeds with Legg-Calvé-Perthes disease?

  Increased intra-articular pressure, such as in synovitis
• What can occur as a result of impaired blood flow in Legg-Calvé-Perthes disease?

  Infarction of all or part of the femoral head may occur
• What are the key points regarding the pathogenesis of Legg-Calvé-Perthes disease?

  • Blood vessels travel along the femoral neck before entering the bone
  • In susceptible breeds, vessels remain superficial
  • Venous drainage may be impaired by increased intra-articular pressure
  • Infarction of the femoral head may occur
• What major problem does bacterial infection of the bone cause in livestock animals 


  Vertebral osteomyelitis - essentially the vertebra collapsed causing compression of the spinal cord leading to hind limb paralysis
• What bacteria caues mandibular osteomyelitis (lumpy jaw )


  Actinomyces bovis
• What fungus caues mycotic osteomyelitis

  Cryptococcus neoformans and paecilomyces spp
• What factors contribute to dogs getting canine metaphyseal osteopathy 


  It is a disease of young, fast growing dogs(3-6 months ) ,usually in large and giant breeds
• Clinical signs of canine metaphyseal osteopathy 


  Swelling and pain in metaphyseal areas of long bones , especially radius and ulna , accompanied by fever ,anorexia
• How do most affected animals recover from this condition CMO


  They recover and excess bone is eventually resorbed