Glanders, Testing and the Question of
Proportion
By Sharan Kumar
The suspension of racing at several centres following
glanders-related concerns has unsettled administrators, trainers, stud farm
owners and racing followers alike. Glanders is a serious disease and
unquestionably demands caution. Yet recent developments raise a fundamental
question: are decisions being guided by complete medical evidence, or by
fear generated by test results that may not tell the whole story?
Unease deepened when horses from closed, biosecure
stud farms with no known history of exposure began returning positive blood
test results, with no clear epidemiological links to explain the findings.
Matters were further complicated when the National Horse Breeding Society of
India (NHBSI) sought a temporary suspension of testing, citing concerns
over testing protocols and interpretation. Alarm increased as repeat samples
were sought from several stud farms near Pune, while Sans Craintes Stud Farm at
Coimbatore came to be viewed as the epidemiological centre following the
movement of mares from Hyderabad, where the situation was more acute.
In Hyderabad, horses that tested positive largely
displayed classical clinical symptoms of glanders, leaving little
ambiguity. The outbreak there was supported by both laboratory confirmation and
visible disease, with the presence of non-thoroughbred horses on the premises
providing a possible route of contamination.
In Bangalore, the Chief Veterinary Officer stated that
horses which tested positive and showed classical symptoms had no exposure to
outside horses, having been stabled for several months. Dr Ulrich “Uli”
Wernery, however, observed that infection could have occurred prior to their
arrival, with clinical signs manifesting later. He added that the lack of
earlier suspicion may point to delayed recognition of the disease rather than
the absence of infection.
Dr Wernery, who
was recently invited by the National Horse Breeding Society of India to
interact with veterinarians and breeders through a webinar, offered valuable
perspective. An internationally respected veterinarian trained in Germany and
long involved in disease control programmes in regions where glanders was once
prevalent, his views are shaped by extensive field experience rather than
theory alone.
His central point is simple but often misunderstood: a
positive blood test is not the same as having glanders. ELISA and similar
serological tests are screening tools. They detect antibodies, not the glanders
bacterium itself. Antibodies, Dr Wernery explains, can sometimes be triggered
by exposure to other bacteria with similar properties, leading to false-positive
results.
For this reason, he stresses that no responsible
diagnosis is made on serology alone. Internationally, laboratory results
are meant to support diagnosis, not replace clinical judgement. A horse can be
confidently said to have glanders only when test results are accompanied by
clear clinical signs such as persistent nasal discharge, respiratory
involvement in advanced cases, or characteristic skin nodules or lesions. In
the absence of such symptoms, declaring a horse infected purely on the basis of
a blood test is scientifically incomplete.
This distinction is particularly relevant in the
current Indian context. Many horses that have tested positive are clinically
normal, eating well, training normally and showing no outward signs of
disease. Dr Wernery therefore poses a simple but critical question: if
glanders is present, where is the disease expression?
His views also help place the recent request to pause
testing in perspective. While the request has come from the NHBSI, the move
itself suggests unease over how results are being generated and, more
importantly, how they are being acted upon. Dr Wernery believes this
underscores the need to reassess testing protocols and result interpretation,
especially when positives emerge without clinical signs or logical transmission
pathways.
He advocates a step-by-step approach to disease
control. An initial positive result should lead to isolation, close
observation, repeat or confirmatory testing and thorough clinical examination.
Drastic measures, he argues, should follow evidence, not precede it.
Epidemiology, clinical presentation and laboratory science must align before
conclusions are drawn.
This leads to the uncomfortable but necessary question
facing racing administrators: has racing been suspended too quickly and too
broadly? Dr Wernery does not minimise risk. Glanders is a zoonotic disease
and public health considerations are paramount. However, he warns that blanket
shutdowns based solely on uncertain or incomplete evidence can inflict serious
damage without necessarily improving disease control.
Drawing from long experience, he recalls that when
glanders was more prevalent, diagnosis was treated as a process, not an
event dictated by a single laboratory report. Horses were monitored over time,
reassessed and observed for clinical progression rather than condemned in
haste.
For administrators and stakeholders, the lesson is not
to lower vigilance, but to strengthen decision-making through clearer
communication, better understanding of testing limits, and closer alignment
between laboratory science and clinical reality.
While Dr Wernery does not directly comment on when or
how racing should resume, his views implicitly outline a pathway for
restoration. Once horses testing positive show no clinical signs, have no
epidemiological links, and are subjected to isolation, confirmatory testing and
sustained observation, they should not continue to paralyse the system. Racing,
in this framework, can resume in centres where surveillance shows no clinical
disease and controls are targeted rather than blanket.
In a situation clouded by uncertainty, his perspective
serves as a reminder that proportion, not panic, is the strongest ally of
science.
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