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 2016
Volume 25, Number 1

C O M M E N TA RY
IN THIS ISSUE
Commentary
International
Third Quarter2015  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  . 2Equine Glanders .  .  .  .  . 3National
Blister Beetles  .  .  .  .  .  .  . 4Hand Protection .  .  .  .  . 4KentuckyEquineLymphosarcoma  .  .  .  . 5In this world nothing can be said to be certain,
except death and taxes.”
I will add another certainty to Benjamin Franklin’s observation, and that is change. Recently attending my 30-year veterinary school class reunion
made that abundantly clear.
When I attended veterinary school, the board
certified radiologists were learning how to use the
newly acquired, latest imaging technology—theultrasound machine. Pain management for horses
primarily consisted of flunixin meglumine, phenylbutazone, and narcotics. The rapid, specific test
called polymerase chain reaction was in no one’s
vocabulary (yet).
People communicated via mail, telephone, or
the radio in the veterinary practice vehicle. When
having a meal with a friend or colleague, no one
was interrupted by a text, cell phone call, or “bling”
of an incoming email or social media post. Computers had disk operating systems (MS-DOS) anda basic personal computer cost $2,300 ($4,200 intoday’s dollars).
Communication has always been importantin the relationship between veterinarians, clients,
and co-workers. However, at the 2015 American
Veterinary Medical Association Convention, it
was sobering to see the numerous lectures oncyberbullying and workplace bullying. Bullying
isn’t limited to playgrounds anymore; it is in theworkplace and online and is a serious issue. People
now have the ability to “comment” about anyone,
on anything, at any time via social media and internet sites. While this can be helpful when users
rate a book, movie, new computer or phone app,baseless, vicious comments are rarely productive
and may result in criminal or civil charges. Truth-

ful complaints are best reserved for the local Better
Business Bureau rather than anonymously online.
Yet some things have not changed and likely
never will. Nothing will ever replace a thoroughhistory and physical examination of an animal as
the first steps in disease diagnosis. All the
cutting-edge diagnostic testing, imaging andmonitoring tech-niques must be interpreted inlight of the behavior and clinical signs exhibitedby the patient. As my anesthesiology professor
pounded into us as vet-erinary students, “Lookat your patient as well as the machines! The
patient never lies!”
And while diagnosticians have an everincreasing arsenal of testing procedures forequine diseases, many challenges remain. Just
because a horse has an antibody titer to apathogen doesn’t necessarily mean it has thedisease; it may simply mean the horse has been
exposed to the pathogen and/or that it was
vaccinated. How high is the titer, and what
diagnostic method was used? What are thesensitivity and specificity of the test? All is dependent upon appropriate interpretation of the test
result in conjunction with the patient history andphysical examination.
Thirty years from now our current
technology will be similarly outdated and likely
be viewed as archaic by a new generation.
Death, taxes, and change will always be withus. One other axiom—by John Lubbock—is also
timeless: “There is nothing so good for the insideof a man as the outside of a horse.”
CONTACT:
Dr. Roberta Dwyer(859) 257-4757
rmdwyer@uky.edu
Maxwell H. Gluck Equine Research Center
University of Kentucky
Lexington, Kentucky

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

Third Quarter 2015

T

Equine Disease Quarterly
Editors

Roberta Dwyer
Alan LoynachanPeter Timoney

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://www.ca.uky.edu/
gluck/index.htm
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 (UK), and other sources
reported the following disease outbreaks.
Vesicular stomatitis (New Jersey serotype) was
reported in the USA, with 192 virus-confirmed
outbreaks in eight states: Arizona, Colorado, Nebraska, New Mexico, South Dakota, Texas, Utah,
and Wyoming. Disease was additionally identified
on 335 premises based on clinical signs.
Influenza was reported by France, the UK,
and the USA. Two cases were involved in a single
outbreak in France. The UK confirmed threeoutbreaks: single cases on two premises and several affected animals on a third premises. All cases
involved unvaccinated horses or ponies. Influenza
was reported as endemic in the USA with outbreaks confirmed in five states.
Equine herpesvirus-1 and -4 (EHV-1, -4) related diseases were recorded in Argentina, France,
Germany, Ireland, the UK, and the USA. EHV-1
associated respiratory disease was diagnosed inGermany (isolated cases), Ireland (single case),
the UK (single case co-infected with strangles),and the USA (several states). EHV-1 abortions
were reported by Argentina, France, the UK, andthe USA. Two outbreaks were identified in France
involving Thoroughbreds and French Trotters,
and single cases were confirmed in Argentina, theUK, and the USA. One case of EHV-1 myeloencephalopathy was recorded in France. Outbreaksof EHV-4 respiratory disease were confirmed in
France (11 outbreaks) and Germany (three outbreaks).
Strangles was recorded in France (13 outbreaks),
Germany (five premises), Ireland (21 cases in four
provinces), Switzerland (three outbreaks), andthe UK (one outbreak). Strangles was reported as
endemic in the USA with disease confirmed on 18
premises in 11 states.
Switzerland reported a single case of EHV-5
co-infection with Theileria equi. Multiple cases of
either EHV-2 or EHV-5 were confirmed in theUSA.
Equine arteritis virus infection was reported ina Warmblood stallion in Germany.
Canada confirmed 41 cases of equine infectious
anemia in four western provinces, the majority in
Saskatchewan and Alberta.

Equine piroplasmosis was reported as endemic
in France.
Germany and South Korea confirmed outbreaksof contagious equine metritis. Germany recorded
outbreaks involving 19 non-Thoroughbreds onfour premises, one of which involved two stallions
and 14 mares on an Icelandic horse farm. Seventyone positive Thoroughbreds on 36 premises wereidentified in South Korea.
One case of coital exanthema (EHV-3 infection) was diagnosed in the USA. The USA also
reported two cases of nocardioform placentitis,
both associated with Amycolatopsis spp.
Salmonellosis was recorded in Germany (onecase), Ireland (one case), and the USA (several outbreaks involving Group B and C1 Salmonella spp).
The USA diagnosed proliferative enteropathy due
to Lawsonia intracellularis in two foals. Outbreaksof rotavirus infection were reported in France (twooutbreaks) and Germany (one case). Two cases ofclostridial enteritis associated with C. perfringens
Type A toxin were identified in the USA.
Thirty-six cases of Eastern equine encephalomyelitis (EEE) were diagnosed in eight states in
the USA, with Florida and Texas having the mostnumerous cases. The vast majority of EEE cases
were in unvaccinated horses.
West Nile virus infection was reported in
France and the USA. Thirty cases were confirmed
in France; all but one occurred in two geographic
areas. The USA reported 58 cases, with the greatest numbers in Texas, Washington, and Colorado,
nearly all in unvaccinated horses. Switzerland
confirmed two cases of tick-borne encephalitis.
A Getah virus outbreak was reported in Japan
involving 25 Thoroughbred horses on one premises. The majority of cases occurred in two year
olds, 10 of which had not been vaccinated.
Rhodococcal disease was reported as endemic
in the USA, with numerous outbreaks in various
states.
Single cases of the following diseases were reported during the third quarter of 2015: ehrlichiosis and borreliosis (Switzerland); and anthrax,
neorickettsiosis, and pythiosis (the USA).

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Equine Glanders: A Diagnostic Approach in GermanyGlanders, one of the oldest known zoonotic
infectious diseases, is caused by the bacterium
Burkholderia mallei. Infection with B. mallei may
cause clinical signs in horses after an incubation
time of three to five days or longer. The disease is
widespread in several countries in South America,
the Middle East, Asia, and Africa. During the last
five years, cases were reported from Afghanistan,Bahrain, Germany, Kuwait, Lebanon, Brazil, Mongolia, Myanmar, Eritrea, India, Iran, Pakistan, andRussia. Notification to the World Organization
for Animal Health (OIE) is compulsory for OIE
member states. Impacted countries face rigorous
restrictions in international trade of equids andtheir products for at least six months.
In 2014, after 60 years of disease freedom, Germany identified a glanders positive horse. Glanders
had been considered eradicated in Western Europe
since the 1960s. This initiated an international discussion concerning adequate methods to confirm
infection or disease.
A glanders case definition is not available fromthe OIE. Consequently, each country must implement its own regulations. For serological testing
and confirmation of clinical suspicion, Germany
relies on the OIE prescribed complement fixation
test (CFT) in combination with the immunoblot
technique. The CFT is prescribed for international
trade by OIE. Unfortunately, the CFT result is
influenced by many parameters, such as the bacterial strains used for antigen production—weuse a certified CFT antigen (ccpro, Oberdorla,
Germany); the complement and hemolytic systems(standardized components are advised to minimize
intrinsic variation); and technical aspects, such as
incubation time and temperature.
The highly specific immunoblot (IB) for glanders is used to exclude false positive CFT results.
Validation data confirm that the IB test is only
positive for infected animals. It must, however,be validated for different geographic regions. IB
validation, following OIE recommendations, is an
ongoing project not yet finalized at the glanders
OIE reference laboratory in Germany. The 2014case of glanders in Germany was identified by thistest combination.

According to our experience, clinically normal
but infected (i.e., IB positive) horses do not showclassic clinical signs. Therefore, the detection of
B. mallei in these horses is highly challenging. At
necropsy, a thorough search for lesions especiallyin nasal cavity, skin, and internal organs is necessary, since they are often barely visible. All lesions
and aberrant tissues must be sampled for further
analysis. To investigate if a horse is infected with B.
mallei, a combination of techniques is used. These
include cultivation, polymerase chain reaction test
(to detect B. mallei DNA), histology (to exclude
other diseases), immunohistochemistry (IHC) tovisualize B. mallei antigen in tissue sections, andexperimental infection of guinea pigs. Finally,
detection of B. mallei may still fail in a significant
number of cases, because few bacteria are present
in glanderous lesions. These laborious and time
consuming procedures require up to seven weeks
to complete before final results are available.
In Germany, serologically positive CFT results
for glanders must be immediately verified by IB
at least twice. Horses that test CFT positive but
IB negative have to be re-tested three times at
two- to three-week intervals; horses that remain
negative are considered uninfected. Suspiciousand outbreak populations must be re-tested at least
three times in two- to three-week intervals withnegative CFT results before restrictions on these
populations can be lifted. Positive CFT resultsthat have been confirmed by IB are considered as
proof for B. mallei infection, even in the absenceof clinical disease or detection of B. mallei. Additionally, isolation, molecular identification and/or IHC identification of the agent in characteristic
lesions constitute unambiguous proof of B. mallei
infection.
CONTACT:
Drs. Mandy C. Elschner, Elisabeth Liebler-Tenorio,and Heinrich Neubauer
Phone: 0049 3641 804428
mandy.elschner@fli.bund.deFriedrich-Loeffler-Institut
Federal Research Institute for Animal Health
Jena, Germany

Figure 1. U.S. geogr
of blister beetles.

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N AT I O N A L

Blister Beetles and Alfalfa: A Potentially Lethal Mix

B
Figure 1. U.S. geographic distributionof blister beetles.

lister beetles belong to a family of plant-feeding
insects (Meloidae) that produce cantharidin,
a toxic defensive chemical. Contact with it in the
blood of live or dead beetles causes blistering of
the skin or mucous membranes of sensitive mammals, especially horses. Cantharidin is stable andremains toxic in dead beetles for a long time, so
animals may be poisoned by eating crushed beetles
in cured hay. The severity of the reaction depends
upon the amount of cantharidin ingested and thesize and health of the animal. The lethal dose forlivestock is estimated to be 0.45 to 1.0 mg of thechemical per kilogram of body weight.
Clinical signs associated with poisoning usuallyappear within hours and include irritation andinflammation of the digestive and urinary tracts,
colic, urinary straining, and frequent urination.
This irritation may also result in secondary infection and bleeding. In addition, calcium levels inhorses may be drastically lowered and the heart
can be damaged. Since animals can die within 72
hours, it is imperative to contact a veterinarian assoon as blister beetle poisoning is suspected.
Meloids in the genus Epicauta, especially the
striped blister beetle group (E. occidentalis, E.
temexia, and E. vittata) are most commonly associated with poisoning of equids. Blister beetles are
attracted to flowering alfalfa, or other blooming
plants, and may be trapped and crushed in hay
during harvest. Blister beetles can be found in
the Central and Eastern United States (see Figure1). In addition to their high cantharidin content(approximately 4 mg/beetle), striped blister beetles
tend to congregate in large clusters along fieldmargins. This can result in high concentrationsof beetles in baled hay. Additional blister beetle
species have been identified in poisonings in otherareas of the United States.

Reducing the Potential for Blister Beetles in
Hay
Tips for Hay Producers:• Learn to recognize blister beetles and understand their behavior. An effective preventive
program will reduce potential problems. Thereis no efficient way to inspect baled hay carefully
enough to ensure that it is free of blister beetles
or cantharidin.
• Blister beetles usually are not active when thefirst cutting of alfalfa hay is made; harvest at thelate bud stage or when the first flowers open
for high quality horse hay.
• Blister beetles are attracted to blooms. Manage harvest intervals to minimize floweringof alfalfa or weeds in hay fields. Practice goodbroadleaf-weed management.
• Check hay fields for blister beetles before cutting from July through early September. They
prefer blooming plants and tend to cluster inmasses near field edges. Avoid harvesting areas
where beetles are present.
• Avoid crimping hay during harvest. Straddle cut
swaths to avoid crushing beetles with tractor
tires.
Tips for Horse Owners:• Reduce the risk of feeding blister beetles tohorses by understanding blister beetle basics,
and by taking the following precautions:• If practical, grow your own alfalfa to ensure
proper preventive management practices.
• Develop a relationship with your hay producer
or broker so that you know their production
practices and hay quality.

CONTACT:
Dr. Lee Townsend(859) 257-7455
Lee.townsend@uky.edu
Department of Entomology
University of Kentucky
Lexington, Kentucky

Hand ProtectionHuman skin is the primary barrier against microbes, toxins, and physical injury. In equine
veterinary care, gloves spare humans from exposure
to harmful organisms, toxins, and pharmaceuticals
such as progesterone analogs and other hormone
products, topical nonsteroidal antiinflammatory
drugs (NSAIDs), oral sedatives, and antimicrobial
drugs like chloramphenicol.

In 1994, the Occupational Safety and HealthAdministration (OSHA) published personal protective equipment standards (29 Code of Federal
Regulations) to regulate workplace protection witha focus on respiratory protection. Hand protection
and workplace clothing have been the subjects ofminimal regulation.

5

Disposable gloves are made of different materials with different levels of protection. The
typical rectal palpation glove prevents skincontact with feces, but does not protect against
substances such as bleach. A latex glove keeps
hands clean when dealing with body fluids, but
provides little skin protection against chemicals.
Glove protection has several measures. Penetration refers to punctures or tears in the glove.
Permeation describes the ability of a substance topass through an intact glove without damaging
the glove material. Permeation is measured bybreakthrough time (BTT). Degradation indicatesalteration of the physical properties of the glove
material upon exposure to chemicals.
Each glove manufacturer produces a glove selection chart to describe its products’ protection against
specific compounds and solvents. Manufacturersof chemicals (including pharmaceuticals) have a
Safety Data Sheet (previously known as Material
Safety Data Sheets) that lists personal protective
equipment (including recommended glove type)as well as other valuable information. However, forsome chemicals, the gloves for hand protection are
simply listed as “impervious” in which case, basic
knowledge about glove types is critical.
Skin exposure occurs before there is a perceptionof leakage through a glove. Measures of permeationand degradation vary considerably between glove
manufacturers. More importantly, the reported
protection often does not reflect the true protection in the field. Wide variations in BTT occur due

to variations between batches, effects of ambient
temperature and humidity, and hand motion.
Hand motion alone has been reported to significantly alter BTT.
Disposable glove choices are generally limited tolatex, nitrile, or vinyl. Each glove has its own attributes. Latex has a smooth fit, offers good dexterity,and protects from bodily fluids and pathogens.
However the material can cause allergic reactions,degrades readily from exposure to chemicals anddisinfectants, and punctures can be inapparent.
Nitrile is a synthetic polymer so there is lessallergic stimulation and it is puncture resistant.
Tears are easily seen. The fit is good, which reduces
hand fatigue and snags. Nitrile has good resistanceto both chemicals and to microbes.Vinyl gloves arecommonly used in the food industry and offer the
least protection against many chemicals. The glove
is not affected by movement, but can be a poor fit.
Rubber or neoprene gloves are recommended
when using many disinfectants as these chemicals
can be caustic and irritating to skin.
No one glove material is resistant to all different
chemicals. Disposable gloves are meant to be discarded and not reused. Read the package insert of any
chemical, pharmaceutical, pesticide, or disinfectant
for information on personal protective equipment,
including specific glove recommendations.
CONTACT:
Dr. Rachel Westerlund(410) 771-4800
rachelwesterlund@gmail.com
Maryland Equine Center, Inc.
Upperco, Maryland

KENTUCKY

Equine Lymphosarcoma

Lymphocytes are an important componentof the equine immune system. Like all cells
within the body, lymphocytes have the potential
to undergo neoplastic (cancerous) transformationthat results in uncontrolled regulation and growth.
Lymphosarcoma is the proliferation of neoplastic
lymphocytes.Equine lymphosarcoma is relatively
common, but the exact incidence is unknown. The
majority of cases occur in horses aged 4-15 years,
but cases have been described in horses of all ages.
Epidemiologic studies suggest no apparent genderor breed predisposition. Like many equine cancers,
the cause of lymphosarcoma is rarely identified, but
certain bacteria and viruses have been implicatedin its development.

Four anatomical categories are frequently utilized for classification of lymphosarcoma. These
categories include: multicentric (generalized orwithin multiple locations), thymic (mediastinal,
within the chest cavity), alimentary (intestinal),
or cutaneous (skin or extranodal).
Clinical signs may develop abruptly or over
several months. Signs can develop due to organ
dysfunction directly related to infiltration byneoplastic lymphocytes; physical obstruction
caused by neoplastic masses; or from neoplastic byproducts (paraneoplastic syndrome). Depression,weight loss, subcutaneous edema, fever, anemia,
and lymphadenopathy (swollen lymph nodes)
are the most commonly observed clinical signs,

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but signs can vary based on the affected organs.
Multicentric, thymic, and cutaneous forms cancompress the airways and esophagus and result
in respiratory or swallowing abnormalities. The
intestinal form can result in colic, diarrhea, andweight loss. Cutaneous nodules may be observedin or under the skin; these masses can be influenced by hormones, thus may wax and wane insize. Various paraneoplastic syndromes have been
described in horses and include: hypercalcemia,
pseudohyperparathyroidism, pruritus and alopecia(itching and hair loss), and immune-mediatedhemolytic anemia and thrombocytopenia.
Veterinarians may suspect a diagnosis of cancer
after visualization of cutaneous nodules, transrectal
palpation of abdominal masses, or detection ofmasses by radiology, ultrasonography, or surgery.
Clinical differentiation of neoplasia from nonneoplastic lesions is difficult. A definitive diagnosis oflymphosarcoma is made by microscopic visualizationof neoplastic lymphocytes in body fluids, fine needle
aspirates, surgical biopsies, or necropsy samples.
The majority of horses diagnosed with lymphosarcoma either die or are humanely euthanizedwithin months after developing clinical signs. Horses
with the cutaneous form typically have longer sur-vival times in comparison to those with other forms.
Treatment is infrequently attempted, but temporary
improvement may occur following surgical excision,or treatment with hormones, chemotherapeutics,
immunomodulators, and corticosteroids.
The University of Kentucky Veterinary Diagnostic Laboratory diagnosed 57 cases of equine lymphosarcoma from September 2009 to September 2015.
Diagnoses were made from 30 surgical biopsies, 23
necropsies, and four cytologic examinations. These
cases represented 51 horses of seven different breeds.
The age of affected animals ranged from a fetus at
300 days of gestation to a 27-year-old gelding; themode was three years of age and included six cases.
Cases were composed of 21 multicentric, 15 cutaneous, 13 lymphoid (lymph node, spleen, or thymus),and five alimentary lymphosarcomas. Additionally,
one case was diagnosed from thoracic effusion(fluid) and two cases from abdominal effusions.
CONTACT:
Dr. Alan Loynachanalan.loynachan@uky.edu(859) 257-8283
Veterinary Diagnostic Laboratory
University of Kentucky
Lexington, Kentucky

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4

Figure 1. U.S. geographic distributionof blister beetles.

Source:http://www2.ca.uky.edu/entomology/entfacts/ef102.asp