Page 1046 - Equine Clinical Medicine, Surgery and Reproduction, 2nd Edition

H aemolymphatic system 1021

VetBooks.ir ANAEMIA OF INFLAMMATORY 9.22
DISEASE (AID)

Definition/overview Inflammatory
stimulus
Also referred to as anaemia of chronic disease, this
is a mild to-moderate decrease in RBCs that occurs
in response to an inflammatory condition. AID
Decreased
Decreased
is perhaps a more appropriate term than anaemia Sequestration erythrocyte bone marrow
of iron in
of chronic disease, as it is inflammatory cytokines macrophages lifespan responsiveness
that cause the anaemia to develop, and this can
be observed within 3–10 days. However, AID fre-
quently develops insidiously.
Mild–moderate
non-regenerative
Aetiology/pathophysiology anaemia
An underlying inflammatory process such as
an abscess, a systemic infection, an immune-
mediated disease or inflammation associated with Fig. 9.22 Pathogenesis of anaemia of inflammatory
neoplasia results in the release of cytokines that disease.
suppress RBC production. Anaemia develops as
a result of cytokine-induced enhanced sequestra-
tion of iron in macrophages of the bone marrow but normal to increased ferritin and bone marrow
and liver, decreased erythrocyte survival time and iron stores, help differentiate AID from iron defi-
bone marrow hyporesponsiveness to erythropoi- ciency. Changes in the leucogram and acute phase
etin. The primary mechanism is decreased avail- proteins may also be observed. Other clinical and
ability of iron for erythrocyte production. This haematological changes reflect the underlying
may be an innate response by the body to make disease.
iron less available for bacterial metabolism and
proliferation (Fig. 9.22). Management
Treatment and resolution of the underlying inflam-
Clinical presentation matory lesion will result in a return to a normal
AID is often identified during investigation of the haematocrit. Specific treatment for anaemia is not
underlying disease. Clinical signs are usually attrib- usually required due to its mild-to-moderate nature.
utable to the underlying inflammatory process and Iron supplementation is not effective.
not to anaemia.
Prognosis
Differential diagnosis The prognosis depends on the nature of the under-
The differential diagnosis includes iron-deficiency lying disease. If this can be successfully treated, the
anaemia. anaemia should resolve.

Diagnosis IRON-DEFICIENCY ANAEMIA
Diagnosis of AID is made by documenting a mild
to-moderate, normocytic, normochromic anaemia Definition/overview
in the presence of an underlying inflammatory or Iron is important for haemoglobin formation within
neoplastic disease. Microcytosis is rarely present. RBCs. Without proper iron availability, animals,
In addition, decreased serum iron and normal to especially young animals, may develop anaemia due
slightly low total iron binding capacity (TIBC), to inadequate stores. Iron-deficiency is uncommon