Canis ISSN: 2398-2942

Fine needle aspirate: ultrasound-guided

Synonym(s): FNA: ultrasound-guided

Contributor(s): Andrew Holloway, Tobias Schwartz


  • For use in the investigation of any accessible mass or cystic lesion and:


  • Jaundice.
  • Unexplained raised liver enzymes.
  • Abnormal appearance of liver on ultrasonographic examination.
  • Diffuse liver disease Liver: chronic disease - overview (inflammatory, infiltrative, neoplastic).
  • Mass lesions.
  • Aspiration of bile.


  • Diffuse diseases (acute or chronic nephritis).
  • Protein losing nephropathy.
  • Mass lesions.


  • Useful for solid masses.

    Avoid cavitatory lesions.

Gastrointestinal tract

  • Mass lesions.


  • Mass lesions of chest wall, mediastinum or lung.
  • Aspiration of thoracic effusions.

Lymph nodes


  • Diffuse or multifocal non-cystic prostatic disease Prostate disease.
  • Solid prostatic masses.
  • Aspiration of cystic structures for diagnostic or therapeutic purposes.


  • Low cost.
  • Minimally-invasive.
  • Rapid.
  • Straightforward in hands of experienced operator.
  • Short time requirement.
  • Often performed without general anesthesia.
  • Minimal risk of complication.


  • Requires patient's coat to be clipped.
  • Difficult to obtain samples in obese patients, from deeply located structures, highly vascularized lesions and in the presence of a large amount of fluid.
  • Samples may be non-diagnostic or non-representative of disease process.
  • Requires significant operator skill.
  • General anesthesia General anesthesia: overview may be required.

Potential problems

  • Seeding of tumor with bladder carcinomas Bladder: neoplasia.
  • Hemorrhage:
  • Penetration of other viscera.
  • Inadequate patient restraint:
    • Movement could result in laceration of vessels or organ.
  • Operator inexperience.
  • Excess intestinal gas or large gall bladder may limit visibility of target tissue.
  • Inadequate equipment (needle diameter too small or too short).
  • Failure to visualize needle due to improper technique or patient factors (obese, excessive respiratory movement).
  • Target may be too small to safely obtain sample (particularly in small dogs and cats).
  • Non-diagnostic sample:
    • Hemodilution - especially spleen and liver.
    • Fibrotic or cirrhotic livers may produce poor samples due to poor exfoliation.
    • Sample size may be too small.
    • Sample not from affected area (multifocal disease).



This article is available in full to registered subscribers

Sign up now to purchase a 30 day trial, or Login

Patient preparation

This article is available in full to registered subscribers

Sign up now to purchase a 30 day trial, or Login


This article is available in full to registered subscribers

Sign up now to purchase a 30 day trial, or Login


This article is available in full to registered subscribers

Sign up now to purchase a 30 day trial, or Login

Further Reading


Refereed papers
  • Recent references fromPubMed.
  • Nyland T G, Wallack S T, Wisner E R (2002)Needle-tract implantation following us-guided fine-needle aspiration biopsy of transitional cell carcinoma of the bladder, urethra, and prostate. Vet Radiol Ultrasound43(1), 50-53PubMed.
  • Bennett P F, Hahn K A, Toal R L, Legendre A M (2001)Ultrasonographic and cytopathological diagnosis of exocrine pancreatic carcinoma in the dog and cat. J Am Anim Hosp Assoc37(5):466-473PubMed.
  • Szatmari V, Osi Z, Manczur F (2001)Ultrasound-guided percutaneous drainage for treatment of pyonephrosis in two dogs. JAVMA218(11):1796-1799, 1778-1779PubMed.
  • Samii V F, Nyland T G, Werner L L, Baker T W (1999)Ultrasound-guided fine-needle aspiration biopsy of bone lesions: a preliminary
     Vet Radiol Ultrasound40(1), 82-86PubMed.
  • Wood E F, O'Brien R T, Young K M (1998)Ultrasound-guided fine-needle aspiration of focal parenchymal lesions of the lung in dogs and cats. J Vet Intern Med12(5):338-342PubMed.
  • Barr F (1995)Percutaneous biopsy of abdominal organs under ultrasound guidance. J Small Anim Pract36(3), 105-113PubMed.
  • Leveille R, Partington B P, Biller DS, Miyabayashi T (1993)Complications after ultrasound-guided biopsy of abdominal structures in dogs and cats: 246 cases (1984-1991). JAVMA203(3), 413-415PubMed.
  • Yamamoto K, Ishiyama N, Yamaga Y, Hayashi T, Kagota K (1991)Ultrasound-guided techniques for biopsy of the kidney of the medium-sized dog. J Vet Med Sci53(2), 345-346PubMed.
  • McNamara MP Jr (1989)Percutaneous procedures guided by color-flow Doppler sonography. AJR Am J Roentgenol152(5), 1123-1125PubMed.
  • Smith S (1989)Ultrasound-guided biopsy. Semin Vet Med Surg (Small Anim)4(1), 95-104 PubMed.
  • Smith S (1985)Ultrasound-guided biopsy. Vet Clin North Am Small Anim Pract15(6), 1249-1262PubMed.