Canis ISSN: 2398-2942

Liver: amyloidosis

Synonym(s): Hepatic amyloidosis

Contributor(s): Nick Bexfield, Kyle Braund

Introduction

  • Cause: usually 'reactive' secondary to chronic infection, chronic inflammation, neoplasia or an immune disorder.
  • Signs: relate to all systems affected by amyloidosis Amyloidosis :
    • Anorexia.
    • Fever.
    • Subcutaneous swellings.
    • Lethargy.
    • Icterus.
    • Lameness.
  • Diagnosis: liver biopsy or fine needle aspiration.
  • Treatment: general supportive treatment, colchicine Colchicine or dimethyl sulfoxide Dimethylsulfoxide.
  • Prognosis: guarded.

Pathogenesis

Etiology

  • Inherited in Shar Pei Chinese Shar Pei (inherited familial Shar Pei febrile disorder).

Predisposing factors

General
  • Chronic infection/inflammation, neoplasia.

Pathophysiology

  • A progressive systemic disease associated with extracellular deposition of insoluble fibrillar proteins with a beta-pleated sheet conformation which results in organ dysfunction.
  • 'Reactive' or secondary amyloidosis is the most common form of the disease in dogs.
  • In 'reactive' amyloidosis, the precursor protein involves portions of serum amyloid A (SAA), which is an acute-phase protein. SAA is synthesized and released by hepatocytes after they have been stimulated by cytokines.
  • Reactive amyloidosis is often associated with chronic infection, inflammation, neoplasia and immune diseases.
  • Shar Pei dogs seem to have defective formation of a protein involved in down-regulation of mediators of inflammation. They may also have a defect which stops them breaking down SAA.
  • Although concurrent amyloid deposition in kidneys, spleen and adrenal glands can occur, clinical manifestations of renal failure (proteinuria and chronic kidney disease Kidney: chronic kidney disease (CKD) ) are most common. Clinical and biochemical evidence of hepatic dysfunction occur less frequently.
  • Occasionally spontaneous hepatic rupture can occur but this is unusual in dogs with hepatic amyloidosis (compared to the cat).
  • Many Shar Peis have a history of recurrent fever, lameness and swelling of the tibiotarsal joint prior to the development of hepatic amyloidosis.

Timecourse

  • Onset often acute followed by chronic clinical course (weeks to months).

Diagnosis

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Treatment

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Outcomes

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Further Reading

Publications

Refereed papers

  • Recent references from PubMed and VetMedResource.
  • Loevan K O (1994) Spontaneous hepatic rupture secondary to amyloidosis in a Chinese Shar Pei. JAAHA 30 (6), 577-579 VetMedResource.
  • Loeven K O (1994) Hepatic amyloidosis in two Chinese Shar Pei dogs. JAVMA 204 (8), 1212-1216 PubMed.
  • DiBartola S P, Tarr M J, Webb D M, Giger U (1990) Familial renal amyloidosis in Chinese Shar Pei dogs. JAVMA 197 (4), 483-487 PubMed.
  • Spyridakis L, Brown S, Barsanti K, Hardie E M & Carlton B (1986) Amyloidosis in a dog: treatment with dimethylsulfoxide. JAVMA 189 (6), 690-691 PubMed.

Other sources of information

  • Scherk M A & Center S A (2005)Toxic, Metabolic, Infectious, and Neoplastic Liver diseases.In:Textbook of Veterinary Internal Medicine. 6th edn. Eds: S J Ettinger & E C Feldman. Philadelphia: W B Saunders. pp 1464-1477.


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