ISSN 2398-2942      

Anemia: laboratory investigation

icanis

Introduction

  • Anemia is a sign of disease NOT a diagnosis, that is, not a disease per se.
  • Identification of anemia on a blood screen demands further investigation to characterize the type and establish the etiology of the anemia.
    Follow the diagnostic tree for Hemolytic Anemia  Hemolytic Anemia.

Is the patient anemic?

  • Anemia is an absolute decrease (of more than 2 standard deviations below the normal mean at normal blood volume) in at least one of: PCV may be normal or increased in dehydrated animals with anemia. This is particularly true of Addisonian dogs Hypoadrenocorticism.
  • Once animal is hydrated hematological analytes should be reassessed.
  • Normal hematological analytes may be present in animals with acute hemorrhage in the first 24-36 h, ie animals become hypovolemic but lose all constituents of blood in equal quantities.
  • Volume support should be given and PCV monitored at regular intervals to establish severity of anemia and response.
  • The spleen may falsely elevate red cell count reducing the degree of anemia:
    • Contraction ’ rapid bolus of stored RBC released.
    • Relaxation ’ splenic storage or RBC removing them from circulation (rare).

Signalment
Age

Clinical signs

  • Weakness.
  • Lethargy.
  • Increased pulse rate; bounding pulse.
  • Secondary signs associated with primary cause of anemia, eg renal failure.
  • Mucous membrane pallor.
  • Evidence of hemorrhage.
  • Discolored urine (hematuria, hemoglobinuria).
  • Disease may be subclinical.

Clinical examination

  • Pale mucous membranes.
  • Tachycardia.
  • Bounding pulse.
  • Heart murmur.

Laboratory investigation

  • Where history and clinical signs are suggestive of anemia, or a general health screen suggests anemia, further tests to establish the etiology are carried out in order to establish:
    • Bone marrow response - consider bone marrow aspiration Bone marrow aspiration and/or biopsy.
    • Erythrocyte characteristics.
  • The questions that need to be answered are:
    • Is the anemia regenerative?
    • Is the regeneration adequate for the severity of the disease?
    • Is there increased destruction or loss of red blood cells?
    • What is the cause of the anemia?

Is the anemia regenerative?

This article is available in full to registered subscribers

Sign up now to obtain ten tokens to view any ten Vetlexicon articles, images, sounds or videos, or Login

What is the cause of the anemia?

This article is available in full to registered subscribers

Sign up now to obtain ten tokens to view any ten Vetlexicon articles, images, sounds or videos, or Login

Is there evidence of hemorrhage?

This article is available in full to registered subscribers

Sign up now to obtain ten tokens to view any ten Vetlexicon articles, images, sounds or videos, or Login

Is the anemia non-regenerative?

This article is available in full to registered subscribers

Sign up now to obtain ten tokens to view any ten Vetlexicon articles, images, sounds or videos, or Login

Further Reading

Publications

Refereed papers

Other sources of information

  • Knottenbelt C (2001) Investigation of anaemia in dogs. In Practice 23, 306-314.
  • Mills J (2000) Anaemia. In: Manual of Canine and Feline Haematology and Transfusion Medicine. 1st edn. Day M J, Mackin A & Littlewood J D (eds), BSAVA Publications, Gloucester, pp 29-42.

Can’t find what you’re looking for?

We have an ever growing content library on Vetlexicon so if you ever find we haven't covered something that you need please fill in the form below and let us know!