Equine Disease Quarterly Newsletter5
traceability of microchips. Equine rescue groups
encounter horses that have lost their identity andendeavor to trace any permanent identification
available to uncover their history.
Current methods available for tracing microchips are limited. Each trace begins with scanning a horse with a microchip-reading device andobtaining a microchip number. But what next?
If the phenotype or history of the horse presents
clues to a breed or discipline group that might
have the horse’s information, this is often the bestplace start. If there is no obvious place to begin
the inquiry, then one contacts the manufacturerof the microchip. The first three digits of the
microchip number indicate the manufacturer orcountry code, which can be looked up online. The
manufacturer provides contact information forthe distributor to which the microchip was sold.
Contacting the distributor yields information for
the next entity that acquired the microchip until
an entity is reached that maintains data connecting
the microchip to the horse. It can be a gruelingprocess.
Attempts to trace microchips have highlighted
some significant challenges. There are multiple
parties involved in and expectedly responsible
for keeping records associated with a microchip.
Failure to keep or transfer records at any step inthe pathway yields a permanent dead end, rendering the microchip essentially useless. The best
outcomes in tracing have been achieved when theend information is maintained by breed registries
or other equine industry groups with a vested
interest in connecting the horse to its unique
identification. Contact with the manufacturer has
reliably been successful in obtaining the distributor
information, but this approach is time consuming
and not practical in urgent situations, such as acontagious disease outbreak.
Some microchip manufacturers do not require
distributors to maintain records on each microchip
sold, which results in a dead-end trace. Finally, apublically accessible online lookup tool for equine
microchips is needed to streamline the trace-backprocess. Such a lookup tool could provide quick
identification and contact information of the main
entity (breed registry, discipline group, registration
system) holding information on that particular
microchip number while maintaining the security
and confidentiality of the data until a specific request is made for information disclosure. Above
all it must be recognized by the equine industry
that simply implanting microchips in horses is notenough. There must be maintenance of data andstructure of traceability built in behind the microchips for their intended purposes to be fulfilled.
CONTACT:
Angela Pelzel-McCluskey, DVM, MS
Angela.M.Pelzel@aphis.usda.gov(970) 494-7391
USDA-APHIS-Veterinary Services
Fort Collins, CO

KENTUCKY

Reducing Horseracing Fatalities:
What Have We Accomplished and Where Do We Go from Here?

The occurrence of fatal injuries to horses inflat racing in North America has decreased
by 23% since the inception of standardized injury
reporting into the Jockey Club’s Equine Injury
Database. The declining trend in fatalities began
in 2013, and achieved statistical significance by
2015. This reduction, we believe, can be attributed
to meaningful change within the culture of horse
racing as expressed in multiple safety initiatives.
In Kentucky, this change has manifested not only
as a decrease in racing fatalities, but also decreases
in regulatory veterinarian-initiated scratches forunsoundness and the number of horses observed to
be unsound post-race. These findings are evidence
that the overall health of the racing population
has improved.Multiple safety initiatives have been
implemented and credited for contributing to theimproved safety record. Examples include:• Constraints on traction devices on horseshoes• Changes to the regulation of therapeutic medications• Systematic, objective monitoring and management of racing surfaces• Implementation of “voided claim” regulations

Presorted Standard
US Postage Paid
Permit 51
Lexington KY

Department of Veterinary Science
Maxwell H. Gluck Equine Research Center
University of Kentucky
Lexington, Kentucky 40546-0099
Address Service Requested

F U N D E D B Y U N D E R W R I T E R S AT L LOY D ' S , LO N D O N

JANUARY 2018
Volume 27, Number 1

C O M M E N TA RY
IN THIS ISSUE
Commentary
International
Third Quarter2017  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  . 2The Role ofFootings .  .  .  .  .  .  .  .  .  .  .  .  . 2National
Neurological
Disorders .  .  .  .  .  .  .  .  .  .  .  . 3

• The National Thoroughbred Racing Association’s Safety and Integrity Alliance accreditationof racetracks• Necropsy programs and Mortality Review
panels• Employment of Safety Stewards• The adoption of an Association of Racing Commissioners’ Model Rule on the Veterinarians’ List
Others assert that the decreased occurrence infatalities is an expression of the Hawthorne Effect, in which there is an improved outcome as aconsequence of a population’s awareness of being
observed. This is perhaps not so rewarding as theidea that the combined effort of the entire spectrum of racing stakeholders made it a safer sport.
But at the end of the day, either way, we’ll take it.
The 23% reduction in racing fatalities is not an
abstraction. Hundreds of horses did not die thatin the past might well have.
The important message is that the occurrenceof racing fatalities is not immutable. This should
serve both as encouragement and warning. Encouragement in that positive change is possible,
and so efforts to improve safety should, andmust, continue. There is additional work to bedone through investigating biomarkers of early
onset orthopedic disease, improving decisionmaking at all levels that further safeguards thelong-term health of the horse during and after
its racing career, identifying business models thatincentivize human and equine health and safety,
and developing relevant and engaging continuing
education programs for all those in contact withrace horses. And the warning? Change can also be
negative. Complacency, the assertion of a mission
accomplished, puts horses and their riders as well as
the sport as a whole at risk, should racing fatalities
be allowed to increase as a consequence of inertia
and a loss of vigilance. The occurrence of racing
fatalities in North America continues to exceedthat experienced elsewhere in the world. Until
North America can legitimately be acknowledged
as a leader in protecting the health, safety, andwelfare of race horses and those who ride or drive
them, our work is far from done.
CONTACT:
Mary Scollay, DVM
mary.scollay@ky.gov(859) 246-2040
Kentucky Horse Racing Commission
Lexington, KY

EquineMicrochips  .  .  .  .  .  .  .  .  .  . 4Kentucky
Reducing
Horseracing
Fatalities .  .  .  .  .  .  .  .  .  .  .  .  . 5

College of Agriculture,
Food and Environment
Department of
Veterinary ScienceThe more things change, the more they remain
the same.”
The epigram was written by Alphonse Karrduring his tenure as editor of the French satiricalmagazine Le Figaro during the middle years of
the nineteenth century. The intended meaning
has been the subject of debate over the years,
but placed in the context of international equine
health reporting, Karr’s musing on change andpermanence is a perfect fit for the Equine Disease
Quarterly (EDQ).
The EDQ was established in October 1992 as acollaboration between the University of Kentucky’s
Department of Veterinary Science, insurance giant Lloyd’s of London, and local Lloyd’s agents.
Its purpose, according to the EDQ’s first Commentary, was to provide accurate information onequine diseases at three levels: in Kentucky, in the
United States, and internationally.
Twenty-five years and 100 issues later, despite
ground-breaking changes in technology, a global
recession, and the emergence of new diseases andthreats from old ones, dedication to the EDQ’s
original goal never has wavered. The publication is,
as it always has been, a primary source of accurate
and unbiased information for the international
equine community. However, 25 years have seen
significant changes.In 1992, the Dow Jones Industrial Average was 3,300. A first-class stamp cost 29
cents. People paid $2,300 for a laptop computer($4,000 adjusted for inflation). The leading Thoroughbred sire was Danzig.
The first edition of the EDQ had a mailing of
2,000. Now more than 14,000 copies are mailed toindividuals in 100 countries and the publication istranslated into Japanese. Unlike most commercial,copyrighted equine publications, articles in the
EDQ can be reprinted in their entirety with proper

acknowledgement. This “secondary” distributionof EDQ information has included veterinary clinic
newsletters, equine industry publications, and vast
distribution via equine information websites.
The International Collating Report in the 1992
inaugural edition covered four diseases in 59 wordsof copy: influenza, contagious equine metritis,
strangles, and equine herpesvirus-1 abortions. In
the October 2017 edition of the EDQ, the International Collating Report included reports of 24
different diseases and occupies a full page of text.
Sincere thanks goes to everyone associatedwith Lloyd’s of London for continued financial
support of this unique publication. Thank you tothe cadre of editors, graphic designers, and staff at
the University of Kentucky who work diligently
to produce a quality publication. To the authorsof articles, thank you for your time and effort incondensing complex concepts and data into meaningful, practical information of 700 words or lessfor the benefit of the horse industry and withouta stipend.
Much has changed in the world and the horseindustry in a quarter century. The Equine Disease
Quarterly remains free to anyone upon request
by print or email. All editions of the EDQ are
available online at http://gluck.ca.uky.edu/equinedisease-quarterly and serve as a historical source of
information on many disease conditions.
And, in closing, thank you to the readers who
provide valuable feedback and commentary of yourown.
CONTACT:
Roberta M. Dwyer, DVM, MS, DACVPM
rmdwyer@uky.edu(859) 218-1122
Department of Animal and Food Sciences
University of Kentucky, Lexington, KY

2

3

I N T E R N AT I O N A L

Third Quarter, 2017

T

Equine Disease Quarterly
Editors

Peter Timoney
Alan Loynachan
Cynthia Gaskill

Staff

Diane Furry
Tawana Brown
Dennis Duross

Correspondence should be
addressed to the editors,
Department of Veterinary
Science, Maxwell H. Gluck
Equine Research Center,
University of Kentucky,
Lexington, Kentucky USA,40546-0099
Telephone (859) 257-4757
Fax (859) 257-8542
Internet address:
http://gluck.ca.uky.edu/
equine-disease-quarterly
Material published in the
Quarterly is not subject tocopyright. Permission istherefore granted toreproduce articles, althoughacknowledgment of thesource and author is requested.
The University of Kentucky
is an Equal Opportunity
Organization.

Printed on recycled paper

he International Collating Centre, Newmarket, United Kingdom, and other sources
reported the following equine disease outbreaks.
Denmark, France, Germany, South Africa,
Switzerland, and the USA reported occurrences of
strangles. The number of recorded outbreaks varied
from one in Denmark, 12 in France, seven in Germany, sporadic occurrences in South Africa, andtwo in Switzerland. The USA reported the diseaseas endemic. At least 33 outbreaks were confirmed
in 13 states, with multiple cases diagnosed on affected premises in four states.
Influenza was reported by the UK (two outbreaks, both involving recently imported Irish
Draft horses) and the USA (a single outbreak).
Germany, South Africa, and the USA recorded
equine herpesvirus 1 (EHV-1) related diseases.
EHV-1 respiratory infections were reported invarious states in the USA. Cases of abortion werediagnosed in South Africa (two cases and one deathin a neonatal foal) and the USA (isolated cases onfour premises). Neurologic disease due to EHV-1
was recorded by Germany (one outbreak involving four horses) and the USA (two outbreaks in
Virginia, one involving two cases and the other,four cases of the disease, two of which died or wereeuthanized).
Respiratory disease associated with equine
herpesvirus 4 infection was reported by France(nine outbreaks), Germany (four outbreaks), South
Africa (single case), and the UK (two outbreaks,
each involving a single case of the disease).
Canada and the USA confirmed cases of equine
infectious anemia during the period under review.
In Canada, the infection was diagnosed on two
premises in Alberta and five in Manitoba. The
total number of infected horses was 14, of which
12 were identified during pre-entry import testingfor events and two represented follow-up testing.

The USA recorded EIA in five states: Colorado(two cases), Illinois (one case), Kansas (three cases),
North Carolina (single case), and Oklahoma (twocases).
Equine piroplasmosis was recorded by France(endemic), South Africa (infection confirmed infive provinces), Switzerland (single case), and theUSA (multiple cases in several states with a vast
majority in Quarter Horse racehorses; iatrogenictransmission confirmed or suspected).
Germany diagnosed contagious equine metritis
in ten Icelandic horses located on five premises.
The USA reported ten cases of Salmonellosis
involving infection with serogroup B Salmonellae
and five with serogroup C3 Salmonellae.
Multiple cases (27) of equine neorickettsiosis
were diagnosed in Kentucky, USA.
Proliferative enteropathy due to Lawsonia
intracellularis was confirmed in several foals in
Kentucky.
France recorded five outbreaks of rotavirus infection, most involving single cases of the disease.
Eastern equine encephalomyelitis was recordedin the USA. The disease was diagnosed in 39 horses
in six states, the largest number in Wisconsin.
South Africa and the USA reported cases ofWest Nile encephalitis. A total of 135 cases werediagnosed in 15 states in the USA, the majority
during the month of September.
Rabies was confirmed in the USA with single
cases recorded in Minnesota and North Carolina.
Rhodococcal related disease was reported as
endemic in the USA with 27 cases diagnosed during the period under review.
A case of tetanus was recorded in a foal in Japan, equine encephalosis in South Africa, seasonal
pasture associated atypical myopathy in Ireland,and ehrlichiosis in Switzerland.

The Role of Footings in Musculoskeletal Disease and PerformanceThe surface is one of the most common factors
cited when an unexpected performance or
injury occurs with a performance horse. While theimportance of surfaces can easily be overstated, unlike many other risk factors, surfaces impact every

horse which competes at a venue. Epidemiologicalresearch also shows that the type of surface—dirt,
turf, or wax-coated sand—has a statistically significant effect on injuries even when other factors
are considered.

The mechanism responsible for the effect of
surfaces on musculoskeletal disease is well established. The skeleton of the horse adapts to the
dynamic loading of the bone. To minimize excess
structure and to provide sufficient bone in highly
loaded regions, bone is absorbed and deposited.
The remodeling process produces a skeleton thatis adapted to the training of the horse. Building the optimal skeleton requires that the horse
performs the specified task during training. The
type of loading during training should match the
expected loading during competition. However,
the maximum performance may not be desirable
during training; for example, the training distance
may be shorter or the jumps lower. The overallloading directions should match that expected incompetition and depends not only on activity but
also on the manner in which the surface supports
the horizontal and vertical loading by the horse.
Both the load rate and the magnitude of loading is critical to bone remodeling and the risk offracture. Surfaces must also provide appropriate
footing during all phases of the gait. Consider the
initial loading on the leading foreleg of a horse at agallop to illustrate the demands. During the initial
impact of the hoof the loads are low, but the impactof the hoof on the surface occurs at a high speed.
The loading, or firmness of the surface, primarily
affects the peripheral bones in the leg. The smallerbones that have adapted to maximize the efficiencyof the horse are quite susceptible to damage. During the secondary loading, the dynamic weight of
the horse is transferred to the leg and long bonesof the horse are then loaded. The cushioningof the surface reduces the rate of loading of thebones and the risk to the more proximal bones ofthe leg. While more research is needed, it is likelythat both the training and competition surface
should have optimal cushioning and firmness toensure proper development of the skeleton while
reducing the risk of injury. In addition to these two
factors, cushioning and firmness, three additional
characteristics have been developed to characterize
the surface response for equestrian competitions,
namely responsiveness, grip, and uniformity.
To minimize risk during competition and tosupport required bone development in training,further research is needed to better understand theeffects of surfaces on performance and injuries of
the athletic horse. In the interim, the current stateof knowledge has been reviewed in white papers for
racing and equestrian sports. Improved processes
for the testing and approval of surfaces such as
those under development by the International
Federation for Equestrian Sports (FEI) show great
promise for implementing current knowledge
in a way that best protects both horse and rider.
Improvements in surfaces along with many otherindustry efforts have led to some of the recent
reductions in catastrophic injuries in race horses,
a critical effort for the protection of the racing
industry as well as all equestrian sports.
CONTACT:
Michael “Mick” Peterson, PhD
mick.peterson@uky.edu(207) 409-6872
University of Kentucky
Lexington, KY

N AT I O N A L

4
to surgical intervention. CSM occurs primarily inyoung horses (3 months to 1 year of age) where it
is a multifactorial disease. In older horses, CSM
is often secondary to osteoarthritis of vertebral
articular process joints.
The neurologic exam for suspect EPM horses
shows asymmetric ataxia, often with upper andlower motor neuron signs and muscle atrophy.
Sarcocystis neurona is the most common cause of
EPM, but Neospora hughesi infection can also cause
similar clinical signs.Several studies of S. neurona
demonstrate that horses residing in states withopossums have an exposure rate of 33% to 53%.
The exposure rate for N. hughesi appears to bemuch lower, although less epidemiologic data isavailable for this organism. Risk factors for S. neurona infection include age (< 5 and >13 years), timeof year (summer and spring more than winter),whether previous cases had been recognized on thefarm, presence of a wooded area, and presence ofopossums on the farm. Prevalence of the disease
was reduced on farms where wildlife had little orno access to feed and if a creek or river was on thepremises. Diagnosis of EPM remains a challenge
and should begin with physical and neurologicalexaminations. This is followed by measurement ofantibodies against the causative organisms in bloodand CSF. Unfortunately, the only definitive test for
EPM is a postmortem examination.
The third common cause of spinal ataxia inhorses is equine degenerative myeloencephalopathy (EDM). This condition has been recognizedin several breeds and has a familial predisposition.
EDM is caused by oxidative damage to proprioceptive relay tracts, thus measurement of vitamin E
has been used as a marker for this condition. Morerecently a genetic marker has been associated withthe disease and genetic testing has proved valuable.

Diagnostic Approach to Equine Neurological DiseasesM

any diseases can affect the central nervous
system of horses but four of the mostcommon disorders are cervical vertebral stenotic
myelopathy (CSM), equine protozoal myeloencephalitis (EPM), equine degenerative myeloencephalopathy (EDM), and equine herpesvirus 1
myeloencephalopathy (EHM).
Regardless of the cause, diagnostic evaluation
begins with a neurological examination, which
provides anatomic localization of the problem
within the central nervous system. Then the diag-nostic investigation continues with more focusedtesting.
If CSM is strongly suspected, radiographs of theneck should be taken. Narrowing of the cervicalvertebral canal in combination with malformationof the cervical vertebrae results in compression of
the spinal cord in CSM patients. Standing lateralradiographs of the cervical vertebrae often reveal
bony malformations and probable narrowing of
the vertebral canal. Myelography is an important
antemortem diagnostic tool and is essential prior

Equine herpesvirus 1 myeloencephalopathy(EHM) is an infrequent but serious outcome ofequine herpesvirus 1 infection. Although the virus has been recognized for a long time, a link toneurological disease was only made in the past fifty
years. More recently, a point mutation in the virus
has been identified that allows it to replicate rapidly
and results in a higher frequency of neurologic disease. Damage to the nervous system develops near
infected blood vessels, which results in “stroke-like”
episodes. The disease usually follows an initial
phase of viral replication in the respiratory tract
and peripheral blood mononuclear cells. Viral
replication also occurs in respiratory epithelium,
gonadal cells, and tissues of the gestating fetus.
Infection can result in fever, respiratory disease,
weak foals, abortion, and neurological disease.
Neurologic signs often include ascending paralysis
with urine dribbling, loss of anal tone and control,
poor tail tone, and pelvic limb weakness.Diagnosis
of EHM is easier to establish when several horseson the same premises present with fever, followed
by ataxia and urine dribbling and in some cases
abortion. When spinal fluid is collected it often
appears xanthochromic as a result of the vasculardamage leading to increased protein but no increase in cell count. Beyond this, diagnosis canbe established by recognition of clinical signs andpositive EHV-1 PCR results of a nasal swab andbuffy coat. Confirmation of the disease is by virus
isolation in cell culture.
Recognition of specific clinical signs, anatomic
localization of lesions, and utilization of diagnostic
tests can help differentiate the common neurologic
diseases.
CONTACT:
Stephen M. Reed, DVM, Dip ACVIM
sreed@roodandriddle.com(859) 233-0371
Rood and Riddle Equine Hospital
Lexington, KY

Traceability of Equine Microchips

For years, equine owners have been implanting microchips into horses for unique andunalterable identification. While the safety andpracticality of this practice is well-established,
there is little information available about traceability of microchips. Given the long lifespan ofhorses, the ability to trace microchips over many
years is necessary.

Reasons to trace microchips are few, but vital
when encountered. Regulatory officials use themicrochip of a horse involved in a disease investigation to trace back to additional exposed horses
or premises. First responders to natural disasters
have significant challenges in identifying ownership of displaced horses. Individuals searching fora lost or stolen horse have a critical reliance on the

23

I N T E R N AT I O N A L

Third Quarter, 2017

T

Equine Disease Quarterly
Editors

Peter Timoney
Alan Loynachan
Cynthia Gaskill

Staff

Diane Furry
Tawana Brown
Dennis Duross

Correspondence should be
addressed to the editors,
Department of Veterinary
Science, Maxwell H. Gluck
Equine Research Center,
University of Kentucky,
Lexington, Kentucky USA,40546-0099
Telephone (859) 257-4757
Fax (859) 257-8542
Internet address:
http://gluck.ca.uky.edu/
equine-disease-quarterly
Material published in the
Quarterly is not subject tocopyright. Permission istherefore granted toreproduce articles, althoughacknowledgment of thesource and author is requested.
The University of Kentucky
is an Equal Opportunity
Organization.

Printed on recycled paper

he International Collating Centre, Newmarket, United Kingdom, and other sources
reported the following equine disease outbreaks.
Denmark, France, Germany, South Africa,
Switzerland, and the USA reported occurrences of
strangles. The number of recorded outbreaks varied
from one in Denmark, 12 in France, seven in Germany, sporadic occurrences in South Africa, andtwo in Switzerland. The USA reported the diseaseas endemic. At least 33 outbreaks were confirmed
in 13 states, with multiple cases diagnosed on affected premises in four states.
Influenza was reported by the UK (two outbreaks, both involving recently imported Irish
Draft horses) and the USA (a single outbreak).
Germany, South Africa, and the USA recorded
equine herpesvirus 1 (EHV-1) related diseases.
EHV-1 respiratory infections were reported invarious states in the USA. Cases of abortion werediagnosed in South Africa (two cases and one deathin a neonatal foal) and the USA (isolated cases onfour premises). Neurologic disease due to EHV-1
was recorded by Germany (one outbreak involving four horses) and the USA (two outbreaks in
Virginia, one involving two cases and the other,four cases of the disease, two of which died or wereeuthanized).
Respiratory disease associated with equine
herpesvirus 4 infection was reported by France(nine outbreaks), Germany (four outbreaks), South
Africa (single case), and the UK (two outbreaks,
each involving a single case of the disease).
Canada and the USA confirmed cases of equine
infectious anemia during the period under review.
In Canada, the infection was diagnosed on two
premises in Alberta and five in Manitoba. The
total number of infected horses was 14, of which
12 were identified during pre-entry import testingfor events and two represented follow-up testing.

The USA recorded EIA in five states: Colorado(two cases), Illinois (one case), Kansas (three cases),
North Carolina (single case), and Oklahoma (twocases).
Equine piroplasmosis was recorded by France(endemic), South Africa (infection confirmed infive provinces), Switzerland (single case), and theUSA (multiple cases in several states with a vast
majority in Quarter Horse racehorses; iatrogenictransmission confirmed or suspected).
Germany diagnosed contagious equine metritis
in ten Icelandic horses located on five premises.
The USA reported ten cases of Salmonellosis
involving infection with serogroup B Salmonellae
and five with serogroup C3 Salmonellae.
Multiple cases (27) of equine neorickettsiosis
were diagnosed in Kentucky, USA.
Proliferative enteropathy due to Lawsonia
intracellularis was confirmed in several foals in
Kentucky.
France recorded five outbreaks of rotavirus infection, most involving single cases of the disease.
Eastern equine encephalomyelitis was recordedin the USA. The disease was diagnosed in 39 horses
in six states, the largest number in Wisconsin.
South Africa and the USA reported cases ofWest Nile encephalitis. A total of 135 cases werediagnosed in 15 states in the USA, the majority
during the month of September.
Rabies was confirmed in the USA with single
cases recorded in Minnesota and North Carolina.
Rhodococcal related disease was reported as
endemic in the USA with 27 cases diagnosed during the period under review.
A case of tetanus was recorded in a foal in Japan, equine encephalosis in South Africa, seasonal
pasture associated atypical myopathy in Ireland,and ehrlichiosis in Switzerland.

The Role of Footings in Musculoskeletal Disease and PerformanceThe surface is one of the most common factors
cited when an unexpected performance or
injury occurs with a performance horse. While theimportance of surfaces can easily be overstated, unlike many other risk factors, surfaces impact every

horse which competes at a venue. Epidemiologicalresearch also shows that the type of surface—dirt,
turf, or wax-coated sand—has a statistically significant effect on injuries even when other factors
are considered.

The mechanism responsible for the effect of
surfaces on musculoskeletal disease is well established. The skeleton of the horse adapts to the
dynamic loading of the bone. To minimize excess
structure and to provide sufficient bone in highly
loaded regions, bone is absorbed and deposited.
The remodeling process produces a skeleton thatis adapted to the training of the horse. Building the optimal skeleton requires that the horse
performs the specified task during training. The
type of loading during training should match the
expected loading during competition. However,
the maximum performance may not be desirable
during training; for example, the training distance
may be shorter or the jumps lower. The overallloading directions should match that expected incompetition and depends not only on activity but
also on the manner in which the surface supports
the horizontal and vertical loading by the horse.
Both the load rate and the magnitude of loading is critical to bone remodeling and the risk offracture. Surfaces must also provide appropriate
footing during all phases of the gait. Consider the
initial loading on the leading foreleg of a horse at agallop to illustrate the demands. During the initial
impact of the hoof the loads are low, but the impactof the hoof on the surface occurs at a high speed.
The loading, or firmness of the surface, primarily
affects the peripheral bones in the leg. The smallerbones that have adapted to maximize the efficiencyof the horse are quite susceptible to damage. During the secondary loading, the dynamic weight of
the horse is transferred to the leg and long bonesof the horse are then loaded. The cushioningof the surface reduces the rate of loading of thebones and the risk to the more proximal bones ofthe leg. While more research is needed, it is likelythat both the training and competition surface
should have optimal cushioning and firmness toensure proper development of the skeleton while
reducing the risk of injury. In addition to these two
factors, cushioning and firmness, three additional
characteristics have been developed to characterize
the surface response for equestrian competitions,
namely responsiveness, grip, and uniformity.
To minimize risk during competition and tosupport required bone development in training,further research is needed to better understand theeffects of surfaces on performance and injuries of
the athletic horse. In the interim, the current stateof knowledge has been reviewed in white papers for
racing and equestrian sports. Improved processes
for the testing and approval of surfaces such as
those under development by the International
Federation for Equestrian Sports (FEI) show great
promise for implementing current knowledge
in a way that best protects both horse and rider.
Improvements in surfaces along with many otherindustry efforts have led to some of the recent
reductions in catastrophic injuries in race horses,
a critical effort for the protection of the racing
industry as well as all equestrian sports.
CONTACT:
Michael “Mick” Peterson, PhD
mick.peterson@uky.edu(207) 409-6872
University of Kentucky
Lexington, KY

N AT I O N A L

4
to surgical intervention. CSM occurs primarily inyoung horses (3 months to 1 year of age) where it
is a multifactorial disease. In older horses, CSM
is often secondary to osteoarthritis of vertebral
articular process joints.
The neurologic exam for suspect EPM horses
shows asymmetric ataxia, often with upper andlower motor neuron signs and muscle atrophy.
Sarcocystis neurona is the most common cause of
EPM, but Neospora hughesi infection can also cause
similar clinical signs.Several studies of S. neurona
demonstrate that horses residing in states withopossums have an exposure rate of 33% to 53%.
The exposure rate for N. hughesi appears to bemuch lower, although less epidemiologic data isavailable for this organism. Risk factors for S. neurona infection include age (< 5 and >13 years), timeof year (summer and spring more than winter),whether previous cases had been recognized on thefarm, presence of a wooded area, and presence ofopossums on the farm. Prevalence of the disease
was reduced on farms where wildlife had little orno access to feed and if a creek or river was on thepremises. Diagnosis of EPM remains a challenge
and should begin with physical and neurologicalexaminations. This is followed by measurement ofantibodies against the causative organisms in bloodand CSF. Unfortunately, the only definitive test for
EPM is a postmortem examination.
The third common cause of spinal ataxia inhorses is equine degenerative myeloencephalopathy (EDM). This condition has been recognizedin several breeds and has a familial predisposition.
EDM is caused by oxidative damage to proprioceptive relay tracts, thus measurement of vitamin E
has been used as a marker for this condition. Morerecently a genetic marker has been associated withthe disease and genetic testing has proved valuable.

Diagnostic Approach to Equine Neurological DiseasesM

any diseases can affect the central nervous
system of horses but four of the mostcommon disorders are cervical vertebral stenotic
myelopathy (CSM), equine protozoal myeloencephalitis (EPM), equine degenerative myeloencephalopathy (EDM), and equine herpesvirus 1
myeloencephalopathy (EHM).
Regardless of the cause, diagnostic evaluation
begins with a neurological examination, which
provides anatomic localization of the problem
within the central nervous system. Then the diag-nostic investigation continues with more focusedtesting.
If CSM is strongly suspected, radiographs of theneck should be taken. Narrowing of the cervicalvertebral canal in combination with malformationof the cervical vertebrae results in compression of
the spinal cord in CSM patients. Standing lateralradiographs of the cervical vertebrae often reveal
bony malformations and probable narrowing of
the vertebral canal. Myelography is an important
antemortem diagnostic tool and is essential prior

Equine herpesvirus 1 myeloencephalopathy(EHM) is an infrequent but serious outcome ofequine herpesvirus 1 infection. Although the virus has been recognized for a long time, a link toneurological disease was only made in the past fifty
years. More recently, a point mutation in the virus
has been identified that allows it to replicate rapidly
and results in a higher frequency of neurologic disease. Damage to the nervous system develops near
infected blood vessels, which results in “stroke-like”
episodes. The disease usually follows an initial
phase of viral replication in the respiratory tract
and peripheral blood mononuclear cells. Viral
replication also occurs in respiratory epithelium,
gonadal cells, and tissues of the gestating fetus.
Infection can result in fever, respiratory disease,
weak foals, abortion, and neurological disease.
Neurologic signs often include ascending paralysis
with urine dribbling, loss of anal tone and control,
poor tail tone, and pelvic limb weakness.Diagnosis
of EHM is easier to establish when several horseson the same premises present with fever, followed
by ataxia and urine dribbling and in some cases
abortion. When spinal fluid is collected it often
appears xanthochromic as a result of the vasculardamage leading to increased protein but no increase in cell count. Beyond this, diagnosis canbe established by recognition of clinical signs andpositive EHV-1 PCR results of a nasal swab andbuffy coat. Confirmation of the disease is by virus
isolation in cell culture.
Recognition of specific clinical signs, anatomic
localization of lesions, and utilization of diagnostic
tests can help differentiate the common neurologic
diseases.
CONTACT:
Stephen M. Reed, DVM, Dip ACVIM
sreed@roodandriddle.com(859) 233-0371
Rood and Riddle Equine Hospital
Lexington, KY

Traceability of Equine Microchips

For years, equine owners have been implanting microchips into horses for unique andunalterable identification. While the safety andpracticality of this practice is well-established,
there is little information available about traceability of microchips. Given the long lifespan ofhorses, the ability to trace microchips over many
years is necessary.

Reasons to trace microchips are few, but vital
when encountered. Regulatory officials use themicrochip of a horse involved in a disease investigation to trace back to additional exposed horses
or premises. First responders to natural disasters
have significant challenges in identifying ownership of displaced horses. Individuals searching fora lost or stolen horse have a critical reliance on the

23

I N T E R N AT I O N A L

Third Quarter, 2017

T

Equine Disease Quarterly
Editors

Peter Timoney
Alan Loynachan
Cynthia Gaskill

Staff

Diane Furry
Tawana Brown
Dennis Duross

Correspondence should be
addressed to the editors,
Department of Veterinary
Science, Maxwell H. Gluck
Equine Research Center,
University of Kentucky,
Lexington, Kentucky USA,40546-0099
Telephone (859) 257-4757
Fax (859) 257-8542
Internet address:
http://gluck.ca.uky.edu/
equine-disease-quarterly
Material published in the
Quarterly is not subject tocopyright. Permission istherefore granted toreproduce articles, althoughacknowledgment of thesource and author is requested.
The University of Kentucky
is an Equal Opportunity
Organization.

Printed on recycled paper

he International Collating Centre, Newmarket, United Kingdom, and other sources
reported the following equine disease outbreaks.
Denmark, France, Germany, South Africa,
Switzerland, and the USA reported occurrences of
strangles. The number of recorded outbreaks varied
from one in Denmark, 12 in France, seven in Germany, sporadic occurrences in South Africa, andtwo in Switzerland. The USA reported the diseaseas endemic. At least 33 outbreaks were confirmed
in 13 states, with multiple cases diagnosed on affected premises in four states.
Influenza was reported by the UK (two outbreaks, both involving recently imported Irish
Draft horses) and the USA (a single outbreak).
Germany, South Africa, and the USA recorded
equine herpesvirus 1 (EHV-1) related diseases.
EHV-1 respiratory infections were reported invarious states in the USA. Cases of abortion werediagnosed in South Africa (two cases and one deathin a neonatal foal) and the USA (isolated cases onfour premises). Neurologic disease due to EHV-1
was recorded by Germany (one outbreak involving four horses) and the USA (two outbreaks in
Virginia, one involving two cases and the other,four cases of the disease, two of which died or wereeuthanized).
Respiratory disease associated with equine
herpesvirus 4 infection was reported by France(nine outbreaks), Germany (four outbreaks), South
Africa (single case), and the UK (two outbreaks,
each involving a single case of the disease).
Canada and the USA confirmed cases of equine
infectious anemia during the period under review.
In Canada, the infection was diagnosed on two
premises in Alberta and five in Manitoba. The
total number of infected horses was 14, of which
12 were identified during pre-entry import testingfor events and two represented follow-up testing.

The USA recorded EIA in five states: Colorado(two cases), Illinois (one case), Kansas (three cases),
North Carolina (single case), and Oklahoma (twocases).
Equine piroplasmosis was recorded by France(endemic), South Africa (infection confirmed infive provinces), Switzerland (single case), and theUSA (multiple cases in several states with a vast
majority in Quarter Horse racehorses; iatrogenictransmission confirmed or suspected).
Germany diagnosed contagious equine metritis
in ten Icelandic horses located on five premises.
The USA reported ten cases of Salmonellosis
involving infection with serogroup B Salmonellae
and five with serogroup C3 Salmonellae.
Multiple cases (27) of equine neorickettsiosis
were diagnosed in Kentucky, USA.
Proliferative enteropathy due to Lawsonia
intracellularis was confirmed in several foals in
Kentucky.
France recorded five outbreaks of rotavirus infection, most involving single cases of the disease.
Eastern equine encephalomyelitis was recordedin the USA. The disease was diagnosed in 39 horses
in six states, the largest number in Wisconsin.
South Africa and the USA reported cases ofWest Nile encephalitis. A total of 135 cases werediagnosed in 15 states in the USA, the majority
during the month of September.
Rabies was confirmed in the USA with single
cases recorded in Minnesota and North Carolina.
Rhodococcal related disease was reported as
endemic in the USA with 27 cases diagnosed during the period under review.
A case of tetanus was recorded in a foal in Japan, equine encephalosis in South Africa, seasonal
pasture associated atypical myopathy in Ireland,and ehrlichiosis in Switzerland.

The Role of Footings in Musculoskeletal Disease and PerformanceThe surface is one of the most common factors
cited when an unexpected performance or
injury occurs with a performance horse. While theimportance of surfaces can easily be overstated, unlike many other risk factors, surfaces impact every

horse which competes at a venue. Epidemiologicalresearch also shows that the type of surface—dirt,
turf, or wax-coated sand—has a statistically significant effect on injuries even when other factors
are considered.

The mechanism responsible for the effect of
surfaces on musculoskeletal disease is well established. The skeleton of the horse adapts to the
dynamic loading of the bone. To minimize excess
structure and to provide sufficient bone in highly
loaded regions, bone is absorbed and deposited.
The remodeling process produces a skeleton thatis adapted to the training of the horse. Building the optimal skeleton requires that the horse
performs the specified task during training. The
type of loading during training should match the
expected loading during competition. However,
the maximum performance may not be desirable
during training; for example, the training distance
may be shorter or the jumps lower. The overallloading directions should match that expected incompetition and depends not only on activity but
also on the manner in which the surface supports
the horizontal and vertical loading by the horse.
Both the load rate and the magnitude of loading is critical to bone remodeling and the risk offracture. Surfaces must also provide appropriate
footing during all phases of the gait. Consider the
initial loading on the leading foreleg of a horse at agallop to illustrate the demands. During the initial
impact of the hoof the loads are low, but the impactof the hoof on the surface occurs at a high speed.
The loading, or firmness of the surface, primarily
affects the peripheral bones in the leg. The smallerbones that have adapted to maximize the efficiencyof the horse are quite susceptible to damage. During the secondary loading, the dynamic weight of
the horse is transferred to the leg and long bonesof the horse are then loaded. The cushioningof the surface reduces the rate of loading of thebones and the risk to the more proximal bones ofthe leg. While more research is needed, it is likelythat both the training and competition surface
should have optimal cushioning and firmness toensure proper development of the skeleton while
reducing the risk of injury. In addition to these two
factors, cushioning and firmness, three additional
characteristics have been developed to characterize
the surface response for equestrian competitions,
namely responsiveness, grip, and uniformity.
To minimize risk during competition and tosupport required bone development in training,further research is needed to better understand theeffects of surfaces on performance and injuries of
the athletic horse. In the interim, the current stateof knowledge has been reviewed in white papers for
racing and equestrian sports. Improved processes
for the testing and approval of surfaces such as
those under development by the International
Federation for Equestrian Sports (FEI) show great
promise for implementing current knowledge
in a way that best protects both horse and rider.
Improvements in surfaces along with many otherindustry efforts have led to some of the recent
reductions in catastrophic injuries in race horses,
a critical effort for the protection of the racing
industry as well as all equestrian sports.
CONTACT:
Michael “Mick” Peterson, PhD
mick.peterson@uky.edu(207) 409-6872
University of Kentucky
Lexington, KY

N AT I O N A L

4
to surgical intervention. CSM occurs primarily inyoung horses (3 months to 1 year of age) where it
is a multifactorial disease. In older horses, CSM
is often secondary to osteoarthritis of vertebral
articular process joints.
The neurologic exam for suspect EPM horses
shows asymmetric ataxia, often with upper andlower motor neuron signs and muscle atrophy.
Sarcocystis neurona is the most common cause of
EPM, but Neospora hughesi infection can also cause
similar clinical signs.Several studies of S. neurona
demonstrate that horses residing in states withopossums have an exposure rate of 33% to 53%.
The exposure rate for N. hughesi appears to bemuch lower, although less epidemiologic data isavailable for this organism. Risk factors for S. neurona infection include age (< 5 and >13 years), timeof year (summer and spring more than winter),whether previous cases had been recognized on thefarm, presence of a wooded area, and presence ofopossums on the farm. Prevalence of the disease
was reduced on farms where wildlife had little orno access to feed and if a creek or river was on thepremises. Diagnosis of EPM remains a challenge
and should begin with physical and neurologicalexaminations. This is followed by measurement ofantibodies against the causative organisms in bloodand CSF. Unfortunately, the only definitive test for
EPM is a postmortem examination.
The third common cause of spinal ataxia inhorses is equine degenerative myeloencephalopathy (EDM). This condition has been recognizedin several breeds and has a familial predisposition.
EDM is caused by oxidative damage to proprioceptive relay tracts, thus measurement of vitamin E
has been used as a marker for this condition. Morerecently a genetic marker has been associated withthe disease and genetic testing has proved valuable.

Diagnostic Approach to Equine Neurological DiseasesM

any diseases can affect the central nervous
system of horses but four of the mostcommon disorders are cervical vertebral stenotic
myelopathy (CSM), equine protozoal myeloencephalitis (EPM), equine degenerative myeloencephalopathy (EDM), and equine herpesvirus 1
myeloencephalopathy (EHM).
Regardless of the cause, diagnostic evaluation
begins with a neurological examination, which
provides anatomic localization of the problem
within the central nervous system. Then the diag-nostic investigation continues with more focusedtesting.
If CSM is strongly suspected, radiographs of theneck should be taken. Narrowing of the cervicalvertebral canal in combination with malformationof the cervical vertebrae results in compression of
the spinal cord in CSM patients. Standing lateralradiographs of the cervical vertebrae often reveal
bony malformations and probable narrowing of
the vertebral canal. Myelography is an important
antemortem diagnostic tool and is essential prior

Equine herpesvirus 1 myeloencephalopathy(EHM) is an infrequent but serious outcome ofequine herpesvirus 1 infection. Although the virus has been recognized for a long time, a link toneurological disease was only made in the past fifty
years. More recently, a point mutation in the virus
has been identified that allows it to replicate rapidly
and results in a higher frequency of neurologic disease. Damage to the nervous system develops near
infected blood vessels, which results in “stroke-like”
episodes. The disease usually follows an initial
phase of viral replication in the respiratory tract
and peripheral blood mononuclear cells. Viral
replication also occurs in respiratory epithelium,
gonadal cells, and tissues of the gestating fetus.
Infection can result in fever, respiratory disease,
weak foals, abortion, and neurological disease.
Neurologic signs often include ascending paralysis
with urine dribbling, loss of anal tone and control,
poor tail tone, and pelvic limb weakness.Diagnosis
of EHM is easier to establish when several horseson the same premises present with fever, followed
by ataxia and urine dribbling and in some cases
abortion. When spinal fluid is collected it often
appears xanthochromic as a result of the vasculardamage leading to increased protein but no increase in cell count. Beyond this, diagnosis canbe established by recognition of clinical signs andpositive EHV-1 PCR results of a nasal swab andbuffy coat. Confirmation of the disease is by virus
isolation in cell culture.
Recognition of specific clinical signs, anatomic
localization of lesions, and utilization of diagnostic
tests can help differentiate the common neurologic
diseases.
CONTACT:
Stephen M. Reed, DVM, Dip ACVIM
sreed@roodandriddle.com(859) 233-0371
Rood and Riddle Equine Hospital
Lexington, KY

Traceability of Equine Microchips

For years, equine owners have been implanting microchips into horses for unique andunalterable identification. While the safety andpracticality of this practice is well-established,
there is little information available about traceability of microchips. Given the long lifespan ofhorses, the ability to trace microchips over many
years is necessary.

Reasons to trace microchips are few, but vital
when encountered. Regulatory officials use themicrochip of a horse involved in a disease investigation to trace back to additional exposed horses
or premises. First responders to natural disasters
have significant challenges in identifying ownership of displaced horses. Individuals searching fora lost or stolen horse have a critical reliance on theEquine Disease Quarterly Newsletter5
traceability of microchips. Equine rescue groups
encounter horses that have lost their identity andendeavor to trace any permanent identification
available to uncover their history.
Current methods available for tracing microchips are limited. Each trace begins with scanning a horse with a microchip-reading device andobtaining a microchip number. But what next?
If the phenotype or history of the horse presents
clues to a breed or discipline group that might
have the horse’s information, this is often the bestplace start. If there is no obvious place to begin
the inquiry, then one contacts the manufacturerof the microchip. The first three digits of the
microchip number indicate the manufacturer orcountry code, which can be looked up online. The
manufacturer provides contact information forthe distributor to which the microchip was sold.
Contacting the distributor yields information for
the next entity that acquired the microchip until
an entity is reached that maintains data connecting
the microchip to the horse. It can be a gruelingprocess.
Attempts to trace microchips have highlighted
some significant challenges. There are multiple
parties involved in and expectedly responsible
for keeping records associated with a microchip.
Failure to keep or transfer records at any step inthe pathway yields a permanent dead end, rendering the microchip essentially useless. The best
outcomes in tracing have been achieved when theend information is maintained by breed registries
or other equine industry groups with a vested
interest in connecting the horse to its unique
identification. Contact with the manufacturer has
reliably been successful in obtaining the distributor
information, but this approach is time consuming
and not practical in urgent situations, such as acontagious disease outbreak.
Some microchip manufacturers do not require
distributors to maintain records on each microchip
sold, which results in a dead-end trace. Finally, apublically accessible online lookup tool for equine
microchips is needed to streamline the trace-backprocess. Such a lookup tool could provide quick
identification and contact information of the main
entity (breed registry, discipline group, registration
system) holding information on that particular
microchip number while maintaining the security
and confidentiality of the data until a specific request is made for information disclosure. Above
all it must be recognized by the equine industry
that simply implanting microchips in horses is notenough. There must be maintenance of data andstructure of traceability built in behind the microchips for their intended purposes to be fulfilled.
CONTACT:
Angela Pelzel-McCluskey, DVM, MS
Angela.M.Pelzel@aphis.usda.gov(970) 494-7391
USDA-APHIS-Veterinary Services
Fort Collins, CO

KENTUCKY

Reducing Horseracing Fatalities:
What Have We Accomplished and Where Do We Go from Here?

The occurrence of fatal injuries to horses inflat racing in North America has decreased
by 23% since the inception of standardized injury
reporting into the Jockey Club’s Equine Injury
Database. The declining trend in fatalities began
in 2013, and achieved statistical significance by
2015. This reduction, we believe, can be attributed
to meaningful change within the culture of horse
racing as expressed in multiple safety initiatives.
In Kentucky, this change has manifested not only
as a decrease in racing fatalities, but also decreases
in regulatory veterinarian-initiated scratches forunsoundness and the number of horses observed to
be unsound post-race. These findings are evidence
that the overall health of the racing population
has improved.Multiple safety initiatives have been
implemented and credited for contributing to theimproved safety record. Examples include:• Constraints on traction devices on horseshoes• Changes to the regulation of therapeutic medications• Systematic, objective monitoring and management of racing surfaces• Implementation of “voided claim” regulations

Presorted Standard
US Postage Paid
Permit 51
Lexington KY

Department of Veterinary Science
Maxwell H. Gluck Equine Research Center
University of Kentucky
Lexington, Kentucky 40546-0099
Address Service Requested

F U N D E D B Y U N D E R W R I T E R S AT L LOY D ' S , LO N D O N

JANUARY 2018
Volume 27, Number 1

C O M M E N TA RY
IN THIS ISSUE
Commentary
International
Third Quarter2017  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  . 2The Role ofFootings .  .  .  .  .  .  .  .  .  .  .  .  . 2National
Neurological
Disorders .  .  .  .  .  .  .  .  .  .  .  . 3

• The National Thoroughbred Racing Association’s Safety and Integrity Alliance accreditationof racetracks• Necropsy programs and Mortality Review
panels• Employment of Safety Stewards• The adoption of an Association of Racing Commissioners’ Model Rule on the Veterinarians’ List
Others assert that the decreased occurrence infatalities is an expression of the Hawthorne Effect, in which there is an improved outcome as aconsequence of a population’s awareness of being
observed. This is perhaps not so rewarding as theidea that the combined effort of the entire spectrum of racing stakeholders made it a safer sport.
But at the end of the day, either way, we’ll take it.
The 23% reduction in racing fatalities is not an
abstraction. Hundreds of horses did not die thatin the past might well have.
The important message is that the occurrenceof racing fatalities is not immutable. This should
serve both as encouragement and warning. Encouragement in that positive change is possible,
and so efforts to improve safety should, andmust, continue. There is additional work to bedone through investigating biomarkers of early
onset orthopedic disease, improving decisionmaking at all levels that further safeguards thelong-term health of the horse during and after
its racing career, identifying business models thatincentivize human and equine health and safety,
and developing relevant and engaging continuing
education programs for all those in contact withrace horses. And the warning? Change can also be
negative. Complacency, the assertion of a mission
accomplished, puts horses and their riders as well as
the sport as a whole at risk, should racing fatalities
be allowed to increase as a consequence of inertia
and a loss of vigilance. The occurrence of racing
fatalities in North America continues to exceedthat experienced elsewhere in the world. Until
North America can legitimately be acknowledged
as a leader in protecting the health, safety, andwelfare of race horses and those who ride or drive
them, our work is far from done.
CONTACT:
Mary Scollay, DVM
mary.scollay@ky.gov(859) 246-2040
Kentucky Horse Racing Commission
Lexington, KY

EquineMicrochips  .  .  .  .  .  .  .  .  .  . 4Kentucky
Reducing
Horseracing
Fatalities .  .  .  .  .  .  .  .  .  .  .  .  . 5

College of Agriculture,
Food and Environment
Department of
Veterinary ScienceThe more things change, the more they remain
the same.”
The epigram was written by Alphonse Karrduring his tenure as editor of the French satiricalmagazine Le Figaro during the middle years of
the nineteenth century. The intended meaning
has been the subject of debate over the years,
but placed in the context of international equine
health reporting, Karr’s musing on change andpermanence is a perfect fit for the Equine Disease
Quarterly (EDQ).
The EDQ was established in October 1992 as acollaboration between the University of Kentucky’s
Department of Veterinary Science, insurance giant Lloyd’s of London, and local Lloyd’s agents.
Its purpose, according to the EDQ’s first Commentary, was to provide accurate information onequine diseases at three levels: in Kentucky, in the
United States, and internationally.
Twenty-five years and 100 issues later, despite
ground-breaking changes in technology, a global
recession, and the emergence of new diseases andthreats from old ones, dedication to the EDQ’s
original goal never has wavered. The publication is,
as it always has been, a primary source of accurate
and unbiased information for the international
equine community. However, 25 years have seen
significant changes.In 1992, the Dow Jones Industrial Average was 3,300. A first-class stamp cost 29
cents. People paid $2,300 for a laptop computer($4,000 adjusted for inflation). The leading Thoroughbred sire was Danzig.
The first edition of the EDQ had a mailing of
2,000. Now more than 14,000 copies are mailed toindividuals in 100 countries and the publication istranslated into Japanese. Unlike most commercial,copyrighted equine publications, articles in the
EDQ can be reprinted in their entirety with proper

acknowledgement. This “secondary” distributionof EDQ information has included veterinary clinic
newsletters, equine industry publications, and vast
distribution via equine information websites.
The International Collating Report in the 1992
inaugural edition covered four diseases in 59 wordsof copy: influenza, contagious equine metritis,
strangles, and equine herpesvirus-1 abortions. In
the October 2017 edition of the EDQ, the International Collating Report included reports of 24
different diseases and occupies a full page of text.
Sincere thanks goes to everyone associatedwith Lloyd’s of London for continued financial
support of this unique publication. Thank you tothe cadre of editors, graphic designers, and staff at
the University of Kentucky who work diligently
to produce a quality publication. To the authorsof articles, thank you for your time and effort incondensing complex concepts and data into meaningful, practical information of 700 words or lessfor the benefit of the horse industry and withouta stipend.
Much has changed in the world and the horseindustry in a quarter century. The Equine Disease
Quarterly remains free to anyone upon request
by print or email. All editions of the EDQ are
available online at http://gluck.ca.uky.edu/equinedisease-quarterly and serve as a historical source of
information on many disease conditions.
And, in closing, thank you to the readers who
provide valuable feedback and commentary of yourown.
CONTACT:
Roberta M. Dwyer, DVM, MS, DACVPM
rmdwyer@uky.edu(859) 218-1122
Department of Animal and Food Science
University of Kentucky, Lexington, KY

Equine Disease Quarterly Newsletter5
traceability of microchips. Equine rescue groups
encounter horses that have lost their identity andendeavor to trace any permanent identification
available to uncover their history.
Current methods available for tracing microchips are limited. Each trace begins with scanning a horse with a microchip-reading device andobtaining a microchip number. But what next?
If the phenotype or history of the horse presents
clues to a breed or discipline group that might
have the horse’s information, this is often the bestplace start. If there is no obvious place to begin
the inquiry, then one contacts the manufacturerof the microchip. The first three digits of the
microchip number indicate the manufacturer orcountry code, which can be looked up online. The
manufacturer provides contact information forthe distributor to which the microchip was sold.
Contacting the distributor yields information for
the next entity that acquired the microchip until
an entity is reached that maintains data connecting
the microchip to the horse. It can be a gruelingprocess.
Attempts to trace microchips have highlighted
some significant challenges. There are multiple
parties involved in and expectedly responsible
for keeping records associated with a microchip.
Failure to keep or transfer records at any step inthe pathway yields a permanent dead end, rendering the microchip essentially useless. The best
outcomes in tracing have been achieved when theend information is maintained by breed registries
or other equine industry groups with a vested
interest in connecting the horse to its unique
identification. Contact with the manufacturer has
reliably been successful in obtaining the distributor
information, but this approach is time consuming
and not practical in urgent situations, such as acontagious disease outbreak.
Some microchip manufacturers do not require
distributors to maintain records on each microchip
sold, which results in a dead-end trace. Finally, apublically accessible online lookup tool for equine
microchips is needed to streamline the trace-backprocess. Such a lookup tool could provide quick
identification and contact information of the main
entity (breed registry, discipline group, registration
system) holding information on that particular
microchip number while maintaining the security
and confidentiality of the data until a specific request is made for information disclosure. Above
all it must be recognized by the equine industry
that simply implanting microchips in horses is notenough. There must be maintenance of data andstructure of traceability built in behind the microchips for their intended purposes to be fulfilled.
CONTACT:
Angela Pelzel-McCluskey, DVM, MS
Angela.M.Pelzel@aphis.usda.gov(970) 494-7391
USDA-APHIS-Veterinary Services
Fort Collins, CO

KENTUCKY

Reducing Horseracing Fatalities:
What Have We Accomplished and Where Do We Go from Here?

The occurrence of fatal injuries to horses inflat racing in North America has decreased
by 23% since the inception of standardized injury
reporting into the Jockey Club’s Equine Injury
Database. The declining trend in fatalities began
in 2013, and achieved statistical significance by
2015. This reduction, we believe, can be attributed
to meaningful change within the culture of horse
racing as expressed in multiple safety initiatives.
In Kentucky, this change has manifested not only
as a decrease in racing fatalities, but also decreases
in regulatory veterinarian-initiated scratches forunsoundness and the number of horses observed to
be unsound post-race. These findings are evidence
that the overall health of the racing population
has improved.Multiple safety initiatives have been
implemented and credited for contributing to theimproved safety record. Examples include:• Constraints on traction devices on horseshoes• Changes to the regulation of therapeutic medications• Systematic, objective monitoring and management of racing surfaces• Implementation of “voided claim” regulations

Department of Veterinary Science
Maxwell H. Gluck Equine Research Center
University of Kentucky
Lexington, Kentucky 40546-0099
Address Service Requested

F U N D E D B Y U N D E R W R I T E R S AT L LOY D ' S , LO N D O N

JANUARY 2018
Volume 27, Number 1

C O M M E N TA RY
IN THIS ISSUE
Commentary
International
Third Quarter2017  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  . 2The Role ofFootings  .  .  .  .  .  .  .  .  .  .  .  . 2National
Neurological
Disorders  .  .  .  .  .  .  .  .  .  .  . 3

• The National Thoroughbred Racing Association’s Safety and Integrity Alliance accreditationof racetracks• Necropsy programs and Mortality Review
panels• Employment of Safety Stewards• The adoption of an Association of Racing Commissioners’ Model Rule on the Veterinarians’ List
Others assert that the decreased occurrence infatalities is an expression of the Hawthorne Effect, in which there is an improved outcome as aconsequence of a population’s awareness of being
observed. This is perhaps not so rewarding as theidea that the combined effort of the entire spectrum of racing stakeholders made it a safer sport.
But at the end of the day, either way, we’ll take it.
The 23% reduction in racing fatalities is not an
abstraction. Hundreds of horses did not die thatin the past might well have.
The important message is that the occurrenceof racing fatalities is not immutable. This should
serve both as encouragement and warning. Encouragement in that positive change is possible,
and so efforts to improve safety should, andmust, continue. There is additional work to bedone through investigating biomarkers of early
onset orthopedic disease, improving decisionmaking at all levels that further safeguards thelong-term health of the horse during and after
its racing career, identifying business models thatincentivize human and equine health and safety,
and developing relevant and engaging continuing
education programs for all those in contact withrace horses. And the warning? Change can also be
negative. Complacency, the assertion of a mission
accomplished, puts horses and their riders as well as
the sport as a whole at risk, should racing fatalities
be allowed to increase as a consequence of inertia
and a loss of vigilance. The occurrence of racing
fatalities in North America continues to exceedthat experienced elsewhere in the world. Until
North America can legitimately be acknowledged
as a leader in protecting the health, safety, andwelfare of race horses and those who ride or drive
them, our work is far from done.
CONTACT:
Mary Scollay, DVM
mary.scollay@ky.gov(859) 246-2040
Kentucky Horse Racing Commission
Lexington, KY

EquineMicrochips  .  .  .  .  .  .  .  .  .  . 4Kentucky
Reducing
Horseracing
Fatalities .  .  .  .  .  .  .  .  .  .  .  .  . 5

College of Agriculture,
Food and Environment
Department of
Veterinary ScienceThe more things change, the more they remain
the same.”
The epigram was written by Alphonse Karrduring his tenure as editor of the French satiricalmagazine Le Figaro during the middle years of
the nineteenth century. The intended meaning
has been the subject of debate over the years,
but placed in the context of international equine
health reporting, Karr’s musing on change andpermanence is a perfect fit for the Equine Disease
Quarterly (EDQ).
The EDQ was established in October 1992 as acollaboration between the University of Kentucky’s
Department of Veterinary Science, insurance giant Lloyd’s of London, and local Lloyd’s agents.
Its purpose, according to the EDQ’s first Commentary, was to provide accurate information onequine diseases at three levels: in Kentucky, in the
United States, and internationally.
Twenty-five years and 100 issues later, despite
ground-breaking changes in technology, a global
recession, and the emergence of new diseases andthreats from old ones, dedication to the EDQ’s
original goal never has wavered. The publication is,
as it always has been, a primary source of accurate
and unbiased information for the international
equine community. However, 25 years have seen
significant changes.In 1992, the Dow Jones Industrial Average was 3,300. A first-class stamp cost 29
cents. People paid $2,300 for a laptop computer($4,000 adjusted for inflation). The leading Thoroughbred sire was Danzig.
The first edition of the EDQ had a mailing of
2,000. Now more than 14,000 copies are mailed toindividuals in 100 countries and the publication istranslated into Japanese. Unlike most commercial,copyrighted equine publications, articles in the
EDQ can be reprinted in their entirety with proper

acknowledgement. This “secondary” distributionof EDQ information has included veterinary clinic
newsletters, equine industry publications, and vast
distribution via equine information websites.
The International Collating Report in the 1992
inaugural edition covered four diseases in 59 wordsof copy: influenza, contagious equine metritis,
strangles, and equine herpesvirus-1 abortions. In
the October 2017 edition of the EDQ, the International Collating Report included reports of 24
different diseases and occupies a full page of text.
Sincere thanks goes to everyone associatedwith Lloyd’s of London for continued financial
support of this unique publication. Thank you tothe cadre of editors, graphic designers, and staff at
the University of Kentucky who work diligently
to produce a quality publication. To the authorsof articles, thank you for your time and effort incondensing complex concepts and data into meaningful, practical information of 700 words or lessfor the benefit of the horse industry and withouta stipend.
Much has changed in the world and the horseindustry in a quarter century. The Equine Disease
Quarterly remains free to anyone upon request
by print or email. All editions of the EDQ are
available online at http://gluck.ca.uky.edu/equinedisease-quarterly and serve as a historical source of
information on many disease conditions.
And, in closing, thank you to the readers who
provide valuable feedback and commentary of yourown.
CONTACT:
Roberta M. Dwyer, DVM, MS, DACVPM
rmdwyer@uky.edu(859) 218-1122
Department of Animal and Food Science
University of Kentucky, Lexington, KY