Equis ISSN 2398-2977

Hypertrophic osteodystrophy

Synonym(s): Hypertrophic osteopathy, Marie's disease, hypertrophic pulmonary osteoarthropathy, HPOA, HO

Contributor(s): Helen Herinckx, Han van der Kolk


  • Cause: unknown etiology. Has been associated with a variety of diseases; usually associated with primary intrathoracic disease; no articular involvement.
  • Signs: bilaterally symmetrical proliferation of connective tissue and subperiosteal bone along the diaphyses of the lower limb bones.
  • Diagnosis: radiography.
  • Treatment: primary cause and symptomatic therapy.
  • Prognosis: guarded to poor.



  • Unknown.
  • Theories include:
    • Hormonal disturbances.
    • Hypoxia.
    • Arteriovenous shunts and neural mechanisms via afferent sympathetics.
  • The disorder is usually associated with intrathoracic disease, especially primary or metastatic neoplasia   Respiratory: neoplasia  .
  • Intrathoracic abscess, ovarian granulosa cell tumor   Ovary: neoplasia - granulosa / theca cell  with metastasis and a dysgerminoma   Ovary: neoplasia - overview  with metastasis, for example, have been described too.

Predisposing factors



  • Increased intact PTH concentration   Endocrine: parathyroid hormone assay  could not be demonstrated in association with equine hypertrophic osteodystrophy.
  • The exact pathophysiology is unknown.


  • Proposed mechanisms include hypoxia, hormonal dysfunction, pulmonary vascular shunting, and neural mechanisms via afferent parasympathetic pathways.
  • Increased blood flow -> fluid retention -> vascular tissue and periosteal proliferation -> new bone formation.


  • Progressive.
  • The onset of the disorder varies from one week to seven months


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Further Reading


Refereed papers

  • Recent references from PubMed and VetMedResource.
  • Packer M & McKane S (2012) Granulosa thecal cell tumour in a mare causing hypertrophic osteopathy. Equine Vet Educ 24 (7), 351-356 VetMedResource.
  • Lewis N L et al (2011) Resolution of hypertrophic osteopathy in a 2-year-old filly. Equine Vet Educ 23 (5), 217-223 VetMedResource.
  • Enright K, Tobin E & Katz L M (2011) A review of 14 cases of hypertrophic osteopathy (Marie's disease) in horses in the Republic of Ireland. Equine Vet Educ 23 (5), 224-230 VetMedResource.
  • Schleining J A & Voss E D (2004) Hypertrophic osteopathy secondary to gastric squamous cell carcinoma. Equine Vet Educ 16 (6), 304-307 VetMedResource.
  • Mair T S & Tucker R L (2004) Hypertrophic osteopathy (Marie's disease) in horses. Equine Vet Educ 16 (6), 308-311 VetMedResource.
  • Van der Kolk J H, Geelen S N J, Jonker F H, Pycock J F & Koeman J P (1998) Hypertrophic osteopathy associated with ovarian carcinoma in a mare. Vet Rec 143, 172-173 PubMed.
  • Leach M W & Pool R R (1997) Hypertrophic osteopathy in a Shetland pony attributable to pulmonary squamous cell carcinoma metastases. Equine Vet J 24, 247-249 PubMed.
  • Mair T S, Dyson S J, Fraser J A et al (1996) Hypertrophic osteopathy (Marie's disease) in Equidae - a review of twenty-four cases. Equine Vet J 28, 256-262 PubMed.
  • Lavoie J P, Carlson G P & George L (1992) Hypertrophic osteopathy in three horses and a pony. JAVMA 201, 1900-1904 PubMed.
  • Chaffin M K, Ruoff W W, Schmitz D G et al (1990) Regression of hypertrophic osteopathy in a filly following successful management of an intrathoracic abscess. Equine Vet J 22 (1), 62-65 PubMed.
  • Sweeney C R, Stebbins K E, Schelling C G, Beech J & Schilling D A (1989) Hypertrophic osteopathy in a pony with a pituitary adenoma. JAVMA 195, 103-105 VetMedResource.