Page 330 - The Veterinary Laboratory and Field Manual 3rd Edition

Haematology 299

5.8 A note on automated systems 3 Gentian violet (hexamethyl pararosanilinie chlo-
ride) and acetic acid are available from suppliers of
laboratory reagents (see Appendix 4).
There are currently a large range of automated 4 Formalin and trisodium citrate are available from
systems available for haematology (for example, most suppliers of reagents (see Appendix 4). The
Coulter counter , Cell Dyn ) but they tend to be RBC diluting fluid must be isotonic with blood
7
6
expensive and may require constant replenish- so that haemolysis does not occur. Normal saline
ment of reagent kits. These systems are fairly can be used but it can cause crenation of the cells.
simple to use once they are set up but regu- Formalin acts as a preservative and sodium citrate
prevents coagulation.
lar quality control and system maintenance is 5 http://ahdc.vet.cornell.edu/clinpath/modules/
essential. Most of the high throughput auto- heme1/intro.htm.
mated systems can use small volumes of blood 6 https://www.labcompare.com/10-Featured-
and can be calibrated for a range of species but Articles/162042-Hematology-Analysers-From-
the ‘normals’ for each species must be regularly Complete-Blood-Counts-to-Cell-Morphology/.
calibrated to ensure accurate results. As outlined 7 https://www.corelaboratory.abbott/us/en/offerings/
category/hematology.
in Chapter 2, most of the automated systems
rely on the use of flow cytometry.
In most district laboratories staff will usu- Bibliography
ally need to rely on manual methods but these
methods need to be performed regularly if the Feldman, B.F., Zinkl, J.G., Jain, N.C. (eds) (2000)
haematology results are to be reliable. For the Schalm’s Veterinary Haematology, 5th edn.
purpose of quality control, it is a good idea to Lippincott, Williams and Wilkins, Pennsylvania.
periodically send duplicate blood samples to a Harvey, J.W. (2001) Atlas of Veterinary Haematology:
Blood and Bone Marrow of Domestic Animals.
laboratory which has an automated haematology Saunders, Philadelphia, PA.
analyser to check that the results from manual Hendrix, C.M., Sirois, M. (2007) Laboratory
techniques are acceptable. Procedures for Veterinary Technicians, 5th edn.
Mosby, St Louis, Missouri. MO.
Pratt, P.W. (1997) Laboratory Procedures for Veterinary
Technicians. 3 Edition. Mosby. St Louis, Missouri
rd
Endnotes Reagan, W.J., Irizarry Rivera, A.R., DeNicola, D.B.
(2008) Veterinary Haematology Atlas of Common
1 Note that if the proportion of band cells exceeds Domestic and Non-domestic Species. Wiley-
the number of mature neutrophils or if the neutro- Blackwell, Ames, IA.
phil count is low but bands are present this could Schalm, O.W., Jain, N.C., Carroll, E.J. (1986)
be a sign of per-acute inflammation or sepsis and Veterinary Haematology, 4th edn. Lea & Febiger,
the animal should be closely monitored. Philadelphia, PA.
2 The dipotassium salt of EDTA is the preferred for- Thrall, M.A. (2006) Veterinary Haematology and
mulation although the disodium salt can also be Clinical Chemistry. Blackwell Publishing, Ames,
used. IA.

Vet Lab.indb 299 26/03/2019 10:26