If Only They Could Talk
Our regular focus on equine
health. This month resident vet
JAMES TATE explains how to tell
if a horse is healthy.
T
When a horse has an infection it produces excessive amounts of
mucus and if this is of any colour except clear or white then it is a
sign of a bacterial infection. There are many different types of bacteria that can cause respiratory disease but in practice ascertaining
which bacteria is causing the infection is often only required if it is
proving difficult to eradicate.
Blood testing
As with scoping, some trainers blood test all horses routinely before
racing whereas others only test horses when a problem is suspected. A blood sample can be tested for many abnormalities but with
regard to respiratory infections and general well-being, analysis of
the white blood cells is most relevant. In theory, the blood test
should be able to tell if the horse is suffering from either a bacterial or viral infection.
The external appearance of the horse
HE racing press is littered with quotes from trainers
citing poor blood results or scopes as reasons for
not running their horses or for poor performances.
However, are these tests alone enough to accurately diagnose a horse with a bacterial or viral respiratory infection or have
they become too heavily relied upon as the only indicators of
whether or not a horse is well?
'Scoping'
The external signs of a
respiratory infection, for
example, coughing, nasal
discharge and blowing
hard after exercise can be
unreliable indicators of
significant
infection
because they can all be
caused by other reasons
such as dust, kick-back or
lack of fitness.
This is why using a flexible
endoscope to see what is
actually inside the horse's
respiratory tract is a useful tool.
Certain trainers 'scope' all
Examining the horse's respira- horses routinely before
tory tract after exercise can be declaring them to run
very helpful in determining whereas others may only
whether or not a horse has a scope horses when a
problem is suspected with
respiratory infection.
an individual horse or if
there is a respiratory problem in the yard at the time.
The endoscope is used to examine the horse's respiratory tract looking for any abnormalities, for example, excessive mucus or blood in
its windpipe. Ideally, this should be carried out no later than two
hours after exercise. Often an examination alone is sufficient to
reach a diagnosis but it is also possible to take samples, either by
means of a tracheal wash or a bronchi-alveolar lavage, which are
sent off to a laboratory for analysis.
The horse's respiratory tract is designed to have a small amount of
mucus so that it can trap foreign agents such as dirt and debris.
Blood testing can be very helpful in determining
whether or not a horse is suffering from
a bacterial or viral infection
Top picture shows a normal windpipe, or
trachea. Below left is endoscopic image of
excessive mucus caused by a respiratory
infection. Right is endoscopic image of
excessive blood caused by exerciseinduced pulmonary haemorrhage.
Respiratory infections considerably
increase the risk of horses bleeding.
However, like most diagnostic
methods, endoscopy is not
one hundred percent reliable
and horses that scope 'clean'
may in fact be just starting to
develop an infection and
horses that scope 'dirty' can
win races. A very public
example of this was the victory of the Mark Johnstontrained Fizzed at the 1998
Saturday Ascot Heath meeting the day after Royal Ascot.
A nasal discharge is suggesConnections announced on
tive of a respiratory infection television that Fizzed had
coughed and scoped dirty the day before but she proceeded to win
anyway.
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This is because a blood test only provides a 'snap shot' of the
horse's blood which can change from day to day.
For example, the blood may be taken just before the horse succumbs
to infection and therefore appear normal or the blood may be taken
just after the horse recovers from the infection when the blood has
not yet returned back to normal. In summary, blood testing can be
helpful but it cannot be completely relied upon, although yards that
carry out a lot of routine blood testing are probably better at interpreting the results as they are more familiar with the blood picture
for each individual horse.
However, as anyone will know who has done a lot of blood testing,
the results are not always one hundred percent accurate - horses
can come back with abnormal blood pictures and win a few days
later and others can come back with excellent blood pictures and
finish tailed off.
Everyone is familiar with the old saying - 'looks well, runs well' and
some argue that this is still the most accurate method of determining the health of the racehorse. This assessment should comprise
an examination of the horse's coat, its condition and muscle mass,
whether or not it is working well, as well as searching for any other
signs of ill-health.
These include leaving feed, weight loss, a high temperature, skin disease such as ringworm or 'cracked heels', and respiratory signs
such as a 'snotty' nose, coughing, raised glands or blowing excessively after exercise. A horse with even a minor skin problem such
as ringworm may have developed this skin disease because its
immune system has become suppressed as a result of another challenge, for example, a respiratory infection.
Horsemen have relied upon these external assessments for many
years before the advent of endoscopy and blood testing to determine whether or not a horse is healthy. This should not be forgotten even if a scope or blood test suggests otherwise.
Continued on page 26
Bacterial infections
Viral infections
A horse suffering from a bacterial infection will usually
have an increased white blood cell count and an
increased percentage of neutrophils because it is these
cells that fight bacterial infections. The horse's fibrinogen is also likely to be raised as a marker of infection.
Below is a typical blood result from a horse with a bacterial infection.
A horse suffering from a viral infection has a characteristic blood picture because there are usually more lymphocytes than neutrophils,
which is the reverse of the normal blood picture. The total white
blood cell count can be high, normal or low depending on the individual horse, how long it has been suffering from the infection and how
suppressed its immune system has become. Below is a typical blood
result from a horse whose immune system has become suppressed as
a result of a viral infection.
Test
Result
Unit
Normal range
(5.5 - 10.0)
White cell count
4.9
x10^9/l
(5.5 - 10.0)
%
(45 - 65)
Neutrophils
38
%
(45 - 65)
21
%
(36 - 48)
Lymphocytes
60
%
(36 - 48)
Monocytes
5
%
(0 - 6)
Monocytes
2
%
(0 - 6)
Eosinophils
1
%
(0 - 3)
Eosinophils
0
%
(0 - 3)
Fibrinogen
4.9
g/l
(0 - 3)
Fibrinogen
4.6
g/l
(0 - 3)
Test
Result
Unit
White cell count
13.5
x10^9/l
Neutrophils
73
Lymphocytes
Normal range
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Discussion and conclusion
(from page 25)
The old saying 'looks
well, runs well' is still
arguably the most
accurate method of
determining whether
or not a horse is
healthy. Top left is a
horse that looks to be
in peak, physical condition. Bottom left is a
horse with a patch of
ringworm on its neck.
Horses with ringworm
often develop the skin
disease because their
immune system has
become suppressed as
a result of another
challenge, for example, a respiratory
infection.
Given that pre-race testing is expensive and not one hundred
percent reliable, should a horse that appears perfectly healthy
be scoped and blood tested? Should it depend on the importance of the race or should it depend on the type of horse? For
example, some argue that running a veteran sprinter with a
respiratory infection is unlikely to cause any long-term harm
whereas running a young novice over three miles in heavy
ground could cause the horse to bleed, become exhausted and
fall.
It is easy to argue both for and against routine pre-race
endoscopy and blood testing. Those trainers that do carry out
routine pre-race testing quickly become used to what is normal
for the individual horses in their yard and this can be very helpful when it comes to interpreting blood tests as well as keeping
an eye on horses that are prone to infections and bleeding.
Conversely, those who do not routinely scope and blood test
tend to become used to looking very closely at the horse for
any outward signs of ill-health, for example, skin disease, loss of
condition or any signs of respiratory disease.
In summary, scoping, blood testing and the external assessment
of the horse are all helpful in determining whether or not it is
healthy but none of them are one hundred percent accurate and
hence a common sense approach must prevail.
At Mark Johnston Racing, all costs associated with the diagnosis and treatment of respiratory disease are covered as part of
the inclusive daily training fee.
MJR’S TEAM OF RESIDENT VETS
HERE at Mark Johnston
Racing we are proud to
offer owners the services of
not one, but two resident
vets to ensure that every
horse of every owner gets
the very best of care
around the clock. And of
course, all veterinary costs
are covered in our all-inclusive daily rate of training
fees. Our vets also provide
fascinating features each
James Tate BVMS MRCVS
month for the Klarion on
various aspects of equine health.
James Tate (left) was born in Harrogate, north Yorkshire, to
a family steeped in racing, his father being trainer Tom
Tate, while his mother Hazel is the sister of legendary
trainer Michael Dickinson.
And his wife Lucinda is the
daughter of retired trainer
Len Lungo. James qualified as a veterinary surgeon at Glasgow University
and worked in a mixed
practice in Cumbria before
joining MJR as senior resident vet in March 2006.
John Martin (right) is from
County Laois in Ireland,
where he was raised on a
John Martin MVB MRCVS
farm and from a young age
had ambitions to be a vet.
He trained in Dublin and after graduating worked at a
veterinary hospital before moving to England to join a
practice in Louth, Lincolnshire. He joined us here at
Kingsley House at the start of 2010.
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