Overview

• Eosinophils are generally involved in inflammatory processes in the body. Primarily involved in killing parasites or regulating the intensity of hypersensitivity reactions.
• Eosinopoiesis stimulated by specific mediators including IL-5 and GM-CSF.
• Attracted into tissue primarily by histamine (mast cells and basophils) and lymphokine (lymphocytes) to neutralize histamine, serotonin and bradykinin resulting in an anti-inflammatory effect. Peroxidase, present in specific eosinophilic granules, exert some anti-inflammatory effect at sites of antigen-antibody interaction, even when histamine is not involved.
• Other functions are fibrin degradation (profibrinolysin produced by developing eosinophils in the bone marrow), phagocytosis and detoxification.
• Kinetics: reservoir of 300-400 eosinophils in bone marrow (75% mature) for every one in circulating blood.
• Lifespan in circulation is very variable from minutes to hours.

Sampling

Tests

Methodologies

• See leukocytes Hematology: leukocyte (WBC).

Availability

• Widely available at commercial laboratory.
• Smears Blood smear preparation can be examined in practice.

Technician (extrinsic) limitations

• Some experience is required for accurate identification of leukocytes.

Result Data

Further Reading

Publications

Refereed papers

• Recent references from VetMedResource and PubMed.
• Sykes J E, Weiss D J, Buoen L C et al (2001) Idiopathic hypereosinophilic syndrome in 3 Rottweilers. JVIM 15, 162-166.

Other sources of information

• Valenciano A C & Cowell R E (2013) Diagnostic cytology and hematology of the dog and cat. 4th edn. Mosby, USA.
• Day M & Kohn B (2012) BSAVA Manual of Canine and Feline Haemotology and Transfusion Medicine. 2nd edn. BSAVA, UK.
• Latimer K S (2011) Duncan and Prasse's Veterinary Laboratory Medicine: Clinical Pathology. 5th edn. Iowa University Press, USA.
• Stockham S L & Scott M A (2008) Fundamentals of Veterinary Clinical Pathology. 2nd edn. Blackwell Publishing.