EQUINE CLINICAL PATHOLOGY - Rossdale & Partners

T h e B e a u f o r t c o t t a g e l a b o r a t o r i e s
Colostrometer reading Concentration IgG g/l Colostrum quality
30% >80 Excellent
Plasma Fibrinogen
This is an acute-phase reactive protein,
which increases in response to inflammation.
Elevations are found in the presence of
tissue damage and this assay may help
with diagnosis and prognosis in cases of
internal abscessation, chronic infectious or
parasitic disease and in cases of exercise
induced pulmonary haemorrhage (EIPH).
The test can be performed on fresh, paired,
non-haemolysed EDTA and serum samples
by subtraction of total serum protein from
plasma protein results, but more accurate
results are obtained from samples collected
into sodium citrate anticoagulant to
measure fibrinogen by direct coagulometric
assay. When measured serially with
serum amyloid A (see right) the kinetics
of the inflammatory response can often
be determined (Fig.9) and this can be
very helpful when monitoring response to
treatment. Fibrinogen is a very useful test
to help diagnose and monitor the response
to treatment for a number of pyogenic
conditions in foals and yearlings, e.g.
Rh. equi and Strep. equi.
Serum Amyloid A (SAA)
This is a highly sensitive, rapidly reacting
inflammatory protein, which can be very
helpful in monitoring early responses to
infection and their response to treatment.
Most normal horses have zero measurable
levels and in the face of acute, particularly
septic inflammation, levels increase quickly
(within 24 hours) to over 20 mg/l and
often more than 100 mg/l. Levels peak
and fall similarly quickly with subsidence
of inflammation when the infection is
controlled (Fig.9). SAA is a very useful
addition to routine neonatal foal ‘profiles’
to help identify those who may have or
may be developing septicaemia and require
antibiotic therapy.
Aspartate Aminotransferase
(AST, AAT, SGOT)
Elevations are seen in the presence of acute
myopathy or hepatopathy. After myopathy,
levels peak at 24-48 hours and return to
baseline by 10-21 days, assuming that no
further damage occurs. This test, taken
with CK at first visit and then 10-14 days
later, can therefore be a useful guide to
recovery from acute myopathy (Fig.10).
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