Hepatomegaly in Cats (Felis) | Vetlexicon
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Hepatomegaly

ISSN 2398-2950


Introduction

  • Hepatomegaly in cats is typically recognized during presentation for non-specific signs such as weakness, lethargy and inappetence.
  • Causes: infectious and toxic causes are typically associated with younger animals while neoplastic and non-suppurative immune-mediated causes are seen more frequently in older cats.
  • Definitive diagnosis is required to establish an appropriate therapeutic plan and to correctly assess the quality of response so that modifications to treatment can be implemented.
  • Prognosis: dependent on the underlying cause and ranges from excellent to hopeless.

Presenting signs

  • Incidental finding.
  • Abdominal distension.
  • Signs associated with underlying disease.

Public health considerations

Special risks

  • Patients with hepatic disease often require hepatic biopsy Biopsy: hepatic for definitive diagnosis, but hepatic insufficiency can result in coagulation factor deficiency resulting in increased tendency to bleed or even DIC Disseminated intravascular coagulation. It is routine to perform coagulation testing in patients undergoing hepatic biopsy.

Pathogenesis

Etiology

Diagnosis

Client history

  • Abdominal swelling.
  • Signs related to primary disease:
    • Lethargy.
    • Anorexia.
    • Polydipsia.
    • Vomiting.
    • Weight loss.

Clinical signs

  • Abdominal distension.
  • Palpable hepatomegaly:
    • Focal.
    • Diffuse.
  • Signs related to primary disease:
    • Pallor (anemia).
    • Cardiac arrhythmia, tachycardia (cardiac failure).
    • Jaundice.
    • Hepatojugular reflex.
    • Free abdominal fluid (congestion/ascites, coagulopathy, amyloidosis).

Diagnostic investigation

Radiography

  • Abdominal radiographs Radiography: abdomen to assess extent and nature of enlargement  Liver: hepatomegaly - radiograph lateral :
    • Assess whether enlargement is generalized or focal (involving one lobe).
    • Assess other abdominal organs for signs of enlargement.
  • In most cases thoracic radiographs Radiography: thorax are also indicated to investigate the possibility of cardiac disease Heart: congestive heart failure, metastatic disease.
    In some cases ascites may be present, which makes radiography a poor imaging technique for evaluation of organ size.

Ultrasonography

  • Hepatic ultrasound Ultrasonography: liver will give information about nature of involvement:
    • Diffuse or focal.
    • Localized or generalized.
  • Neoplastic lesions may be focal or diffuse.
    Benign and malignant lesions cannot be distinguished by ultrasonographic examination.
  • Hepatic congestion produces dilated blood vessels within liver parenchyma  Liver: congestion - ultrasound  .
  • Ultrasound guided biopsy Biopsy: ultrasound-guided or fine needle aspiration Fine-needle aspirate of lesion.
  • Used to assess for presence of underlying pathology, eg echocardiography for pericardial effusion or examination of vena cava for obstruction: visible obstruction of altered portal flow characteristics.

Histopathology

  • Histopathology of biopsy specimen obtained at surgery or percutaneously may be necessary to provide definitive diagnosis.
    Check clotting parameters before biopsy.

Biochemistry

Hematology

  • May give some clue as to nature of disease:
    • Anemia.
    • Inflammatory white cell picture (hepatitis).
    • Septic white cell picture (infectious disease).
    • Evidence of leukemia.

Cytopathology

  • In some diseases cytopathological examination of fine needle aspirate samples may give an indication of diagnosis, eg lymphoma.

Other

Confirmation of diagnosis

Discriminatory diagnostic features

  • Clinical examination.

Definitive diagnostic features

  • Imaging liver size.
  • Histopathology for definitive diagnosis.

Gross autopsy findings

  • Enlarged liver.

Differential diagnosis

  • Other organomegaly Abdominal organomegaly:
    • Gastric distension.
    • Splenomegaly.
    • Neoplasia of lymph node.
  • Abdominal distension due to ascites.

Treatment

Standard treatment

  • Treat underlying disease.
  • May require surgical intervention.

Prevention

Outcomes

Prognosis

  • Depends on diagnosis.
  • Ranges from excellent to hopeless.

Expected response to treatment

  • Improvement in clinical signs.
  • Return of liver size to normal.

Reasons for treatment failure

  • Failure to identify and treat underlying disease.
  • Untreatable underlying disease.

Further Reading

Publications

Refereed papers

  • Recent references from PubMed and VetMedResource.
  • Cuccovillo A & Lamb C R (2002) Cellular features of sonographic target lesions of the liver and spleen in 21 dogs and a cat. Vet Radiol Ultrasound 43 (3), 275-278 PubMed.
  • Wang K Y, Panciera D L, Al-Rukibat R K et al (2002) Accuracy of ultrasound-guided fine-needle aspiration of the liver and cytological findings in dogs and cats: 97 cases (1990-2000). JAVMA 224 (1), 75-78 PubMed.
  • Post G & Patnaik A K (1992) Nonhematopoietic hepatic neoplasms in cats - 21 cases (1985-1988). JAVMA 201 (7), 1080-1082 PubMed.