Page 66 - The Veterinary Laboratory and Field Manual 3rd Edition

Setting up and using a laboratory service 35

service. Once a system of communication has
pathogens. Tissues for histological examina- been set up with submission guidelines for
tion may be fixed in 10% buffered formalin veterinary field and extension staff and transpor-
for later examination. If samples are submit- tation and/or postal links for sample delivery the
ted for histology ensure that there is a full provision of diagnostic services becomes easier.
description of any gross abnormalities along Initially, however, it may be necessary for labora-
with relevant clinical information. Without tory staff to pay frequent visits to animal health
good-quality samples, and the necessary extension units to deliver sample collection kits
background information, the interpretation (see Figure 1.32) and to collect samples. A list of
of histology results can be difficult. Tissue suggested materials for a sample collection kit is
impression smears and smears of material provided in Table 1.3. The requirements for such
from discharges and faeces can also be pre- kits will depend on the resources already avail-
pared. Blood smears can be made directly able to livestock extension/animal health staff.
after blood sampling and can be fixed in If the regional laboratory units are also respon-
methanol and stored for later staining and sible for the storage and distribution of vaccines
examination at the laboratory. Whole blood then the infrastructural network already pres-
can be collected from representative sick ent may provide a useful distribution source
and healthy animals and left to clot over- for samples and sample collection equipment
night at room temperature. Placing the to and from the laboratory or extension units.
blood tubes in the refrigerator (4 C) for Another benefit of linking the two services is the
o
another 4 h often enhances the contraction ready availability of a cold chain. Each diagnostic
of the clot. Serum can be separated the fol- facility supplied with a post-mortem kit should
lowing day and placed in labelled containers have an autoclave available for sterilization
before dispatch to the laboratory. purposes. If no regular electricity is available, a
gas-heated autoclave or a pressure cooker can
be used.
5 All samples must be labelled with the ani-
mal’s identification number, a note of what
the sample is, from where it was collected,
and the date of collection.
6 Veterinary laboratories can provide a lot of
useful information to assist in the selection
of suitable samples and can also assist with
making a diagnosis. Contact the laboratory
directly if specific guidance is required before
samples are collected.

Sample collection kits Figure 1.32 Sample collection box designed for
carriage in a vehicle. The box has several compart-
In the early development of a new veterinary ments to limit shaking and breakage of the contents
laboratory service it is often difficult to pro- during transportation for field work. This example
vide sufficient sample collection materials and is a wooden box. When available, plastic boxes are
sample collection services for the evolving field more suitable because they are easier to clean.

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