EQUINE CLINICAL PATHOLOGY - Rossdale & Partners

G u i d e t o e q u i n e c l i n i c a l p a t h o l o g y
Fig.7: serum protein electrophoresis
fibrinogen spike in heparinised plasma
Test : ELECTR Gel 2 – 5 16/05/2002
Fig.8: serum protein electrophoresis
monoclonal beta 2 globulin 'sky rocket'
Test : ELECTR Gel 1 – 8 30/05/2002
Fraction Rel% G/L
1 5.4 2.48
2 19.8 9.11
3 17.5 8.05
4 36.0 16.56
5 21.3 9.8
Total G/L 46.00
Serum Immunoglobulin G (IgG)
As there is no transplacental transfer of
IgG before birth, foals are born essentially
agammaglobulinaemic. During the last few
months of gestation, mares concentrate
IgG in their colostrum. Foals’ intestines are
capable of absorbing IgG for their first 12
hours of life. Providing the mare makes
colostrum of good quality in terms of IgG
concentration, she does not ‘run milk’
before foaling and the foal sucks sufficient
colostrum within the first 12 hours, the foal
acquires good circulating IgG levels and
therefore adequate passive immunity.
Foals should have their serum IgG levels
checked as a routine preventive medicine
policy. Serum samples collected from foals
after 12 hours of age should have IgG
levels of more than 4 g/l and ideally more
than 6 g/l. Levels of less than 2 g/l indicate
failure of transfer of colostral immunity and
levels of 2-4 g/l indicate partial failure.
Fraction Rel% G/L
1 2.1 1.91
2 9.5 8.65
3 9.5 8.65
4 71.2 64.79
5 7.6 6.92
Total G/L 91.00
Foals with levels below 4 g/l are considered
at risk for neonatal infections and should be
transfused with hyperimmune plasma and
their serum IgG levels re-checked 24 hours
later to make sure that IgG levels have risen
to acceptable levels.
Our experience suggests that none of the
currently available ‘stable-side’ foal serum
IgG tests are reliably accurate at the 0-4 g/l
end of the scale and we measure IgG by an
immunospectrophotometric method run on
our autoanalyser.
IgG can be measured in colostrum
immediately after parturition semiquantitatively,
using a refractometer
(Colostrometer) (see table on page 22). If
readings suggest an IgG level of less than
45 g/l, the foal should be considered for
donor colostrum supplementation by bottle
or stomach tube.
21