Page 58 - The Veterinary Laboratory and Field Manual 3rd Edition

Setting up and using a laboratory service 27

Figure 1.19 Examination of the udder of a cow. Note the presence of any swelling, unusual heat or red-
ness or evidence of pain during palpation. Examine each teat and the milk secreted from each quarter.
If the milk is discoloured or very thick it may indicate that the cow has mastitis but it could also mean
that the cow has recently calved so make sure that the animal is examined carefully and check the case
history. Illustration: Louis Wood.

Figure 1.20 A simple test for mastitis is the California
Mastitis Test which is available as a kit. Illustrated is a
representative plastic squeeze bottle (A) which contains
the reagent for the test and a typical plastic paddle (B).
The paddle has four shallow cups which can be marked to
indicate which quarter of the cow’s udder the milk sample
was collected from. A few drops of reagent are added
to 6–7 drops of milk from each quarter. If the milk sam-
ple precipitates it indicates that there are inflammatory
proteins and cells present. Often only one quarter of the
cow’s udder may be affected. If it is necessary to collect
a milk sample for microbiological culture collect it asepti-
cally. To do this, wipe the teat(s) with an antiseptic before
squeezing the teat to collect the milk. Usually the first few
drops are discarded and 3–5 ml collected into a sterile jar.
The jar should be labelled to indicate the date, the identity
of the animal (age, breed, tag number and so on) the quar-
ter of the udder affected, the name of the farmer and the
submitting animal health professional. In most cases
the veterinary officer would add a case history to indicate
the presence or absence of other clinical signs and the
health history of the animal. Illustration: Louis Wood.

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