Animal health update

              Oklahoma Animal
Disease Diagnostic
Laboratory
(405) 744-6623
FAX (405) 744-8612
Teaching Hospital
Small Animal
(405) 744-7000
Large Animal
(405) 744-7000
Administration
(405) 744-7000
Outreach
(405) 744-7672
FAX (405) 744-6265
In this Issue:
Veterinary
Clinical Sciences
Welcome to Dean Jean
Sander
Scrapie: A regulatory
perspective
Equine Herpes Virus Type I
Alternative therapeutic
options for management of
chronic or recurring urinary
tract disease
Anthelmiatics use in goats
Service dogs and veterinary
medicine
OADDL
Cytauxzoonosis
Common herbicide/pesticide
questions
Equine piroplasmosis
Trichomoniasis in Oklahoma
Fall Conference 2011
Animal Health Update SUMMER 2011
The Newsletter of the Center for Veterinary Health Sciences
Oklahoma State University
Consultations and referrals can be made by contacting the Oklahoma State
University Veterinary Medical Teaching Hospital at (405) 744-7000 or The referring
veterinarian toll free line at 1-866-654-7007.
Veterinary Clinical Sciences
Center for Veterinary Health Sciences
A Big Cowboy
Welcome to the
new CVHS Dean,
Dr. Jean Sander
Dr Jean Sander will begin her appoint-ment
as the OSU CVHS Dean on
August 1, 2011. She was born close
to Washington DC where her father
was a food scientist with USDA. Dr.
Sander actually grew up in the Chicago
suburbs. Dr. Sander earned a BS
degree in Biology from Elmhurst
College, where her mother was a
French Professor. Upon graduation
from Elmhurst College, Dr. Sander
left Chicago and pursued a music
career as a lead singer in a pop music
band.
After her music career, Dr. Sander
pursued her interest in veterinary
medicine, working as a veterinary
assistant in a companion animal prac-tice
and on a dairy and swine farm
to expand her animal experiences. Dr.
Sander was a member of the charter
class at the University of Wisconsin
School of Veterinary Medicine. She
subsequently completed her post-
DVM poultry education program
at the University of Georgia (UGA)
where she received her Master of Avian
Medicine (MAM) degree at the Poul-try
Diagnostic and Research Center
(PDRC).
Dr. Sander’s first faculty position
was at UGA with the Cooperative
Extension Service where she served
as a poultry health specialist. After
2 years, she was transferred into a
teaching and research appointment
within the PDRC. She established
a solid research program, provided
health services through the diagnostic
lab, and taught at the undergraduate,
professional and graduate student
level eventually being asked to lead
the MAM program.
Dr. Sander is currently serving as
Associate Dean for Academic and
Student Affairs at The Ohio State
2 | Veterinary Health Sciences
University College of Veterinary Medicine. She consid-ers
this administrative experience to have been very
rewarding and an excellent way to give back to the
veterinary profession.
Dr. Sander is looking forward to using her energy and
skills to build and enhance the veterinary profession
in Oklahoma as the Dean of CVHS. She invites other
like minded professionals to join her in making this
a sustainable career path for gifted and interested
young people.
Scrapie: A Regulatory
Perspective
Scrapie is a fatal, degenerative disease affecting the
central nervous system of sheep and goats. It is among
a number of diseases classified as transmissible spongi-form
encephalopathies (TSE) all of which are thought
to result from the accumulation of abnormal cellular
“prion” proteins in the brain. Unlike bovine spongiform
encephalopathy (BSE), natural transmission of scrapie to
other species has not been shown. Susceptible animals
are typically infected as young lambs through contact
with the placenta or birth fluids from infected ewes.
Although rams are susceptible to the disease, they are
not known to transmit the infection. However, ram
genetics will contribute to the susceptibility of their
offspring. Incubation period for this disease is gener-ally
2 to 5 years and is invariably fatal. Clinical signs
include behavioral changes, neurological/gait abnor-malities,
weakness, cachexia, and intense pruritus (the
name “scrapie” was coined because infected animals
will usually scrape their wool off from all the itch-ing
and rubbing). Death occurs within several weeks
to months after onset of clinical signs. Although the
disease is more prevalent in black-faced sheep, all
breeds are susceptible.
Diagnosis vs. Genotyping
Antemortem diagnosis of scrapie is from lymphoid
tissue biopsy of the third eyelid or rectal mucosa, and
postmortem diagnosis is from the obex of the brainstem
(both by immunohistochemistry). This test deter-mines
infection and is generally only used on scrapie
suspects, exposed animals, or for slaughter surveil-lance.
Genotyping is a DNA test that identifies the
genes that control scrapie susceptibility or resistance.
This test only measures vulnerability to scrapie and
not infection. A few drops of whole blood collected
on a FTA® card is the sample used by most approved
laboratories. Though there are multiple genes express-ing
different levels of susceptibility, codon 171 is the
gene most focused on in the U.S. At this gene, “QQ”
animals are highly susceptible to scrapie infection
if exposed, “QR” are rarely susceptible if exposed,
and “RR” are highly resistant. So in essence, a 171
QQ fetus exposed to a scrapie infected placenta will
most likely result in infection of the newborn. Using
this information, sheep producers can select breeding
stock that will spawn resistant offspring. For example,
if a RR ram is bred to a QQ ewe, a QR lamb will be
produced every breeding. This is the reason RR rams
are desirable, because they can be bred to susceptible
ewes and still produce offspring that is “rarely suscep-tible”.
So essentially, disease vulnerability can be well
addressed by ram selection alone without having to
focus on the breeding females. There are many traits
in sheep and goats that must be evaluated when deter-mining
breeding potential; genotype is another that
can be added to that list. Accredited veterinarians who
are working with producers to conduct genotyping are
strongly urged to contact USDA Veterinary Services
(VS) to obtain the forms necessary to ensure that the
tests are official. Currently, however, The Oklahoma
Department of Agriculture and USDA VS are offering
free genotyping services to eligible Oklahoma sheep
flocks. These programs increase disease surveillance
in Oklahoma while providing a service to producers.
National Scrapie Eradication Program
TSEs are the subject of increased attention and concern
because of the discovery of BSE in cattle and the link
between it and variant Creutzfeldt-Jakob disease in
humans. In addition to the significant production losses
experienced by infected flocks, the presence of scrapie
in the U.S. has placed burdens and restrictions on the
domestic and international markets for breeding stock,
semen, embryos, meat, and bone meal. In all, scrapie
is estimated to cost the U.S. sheep industry over $20
million annually. The combination of these factors
led the USDA in 2001 to announce an accelerated
program to eradicate scrapie in the nation’s sheep and
goat flocks. The National Scrapie Eradication Program,
coordinated by USDA VS, is a joint effort that includes
participation by state governments, industry, veterinar-ians,
and producers. This program is succeeding, and
Animal Health Update | 3
the prevalence of scrapie has decreased by 80 percent
since 2003. Veterinarians and producers can contrib-ute
significantly to this program by:
• Officially identifying sheep and goats per federal
and state regulations.
In Oklahoma, sheep and goats of any age must be
officially identified before being moved for sale,
exhibition, slaughter, or change of ownership. If
unsure whether a particular sheep or goat needs
to be identified, tag it.
Official ear tags and applicator pliers are avail-able
free of charge from USDA VS.
• Select for genetically resistant breeding stock using
genotyping.
• Reporting suspect animals to the State Veterinar-ian’s
Office (405-ALL-STAR) or USDA VS Office
(405-751-1701).
For more information regarding scrapie, free geno-typing,
or identification requirements please contact
Dr. Justin Roach
Contributed by:
Justin Roach, DVM, Staff Veterinarian
Oklahoma Department of Agriculture, Food,
and Forestry
(405) 522-8396 or justin.roach@ag.ok.gov
Equine Herpes Virus Type
I and Equine Herpes
Myeloencephalopathy
This brief review article is in response to the recent
incidence of horses being diagnosed with neuropathic
EHV-1 infection that competed at the NCHA Western
National Championships in Ogden, Utah (April 29 –
May 8, 2011.) Horses from many states attended this
show and could have possibly been exposed to this
strain of EHV-1. Since then state veterinarians have
been working diligently to prevent the further spread
of the disease.
Introduction
Equine Herpes Virus Type I (EHV-1) is a DNA virus
that affects horses and other mammals including but
not limited to camelids. This virus is most commonly
recognized as causing respiratory disease in horses less
than 5 years of age; however it can also cause abortion
in any aged pregnant mare. Neurologic disease is
caused by certain strains of equine herpes virus type
I can also occur.
Transmission
Most horses are exposed to EHV-1 by one year of age
and they typically develop subclinical infection. The
respiratory form of EHV-1 may result in mild clinical
signs that go unnoticed or resolve without treatment.
Once horses are exposed to EHV-1 they can become
latently infected and carry the virus for life. These
horses can be silent shedders of the virus providing a
mechanism by which other horses can be exposed and
subsequently infected. These silent carriers offer an
explanation of how an outbreak can occur even in a
closed herd. Transmission of EHV-1 occurs via direct
contact with the virus due to ingestion or inhalation.
This can occur by direct nose to nose contact with an
infected horse, exposure to aerosolized viral particles,
or direct contact with an infected fomite such as a
bridle, feed, or water bucket. Nasal shedding can occur
in clinically normal horses, as well as those showing
illness and can continue several weeks.
Clinical Signs
Clinical signs of EHV-1 may vary with different strains.
The respiratory form of the disease typically mani-fests
with fever, serous nasal and ocular discharge,
and coughing at 2-10 days following exposure. These
same signs may precede the onset of neurologic signs.
Secondary bacterial infections can follow the respira-tory
form. Uncomplicated viral respiratory infection
typically resolves in 1-2 weeks. Abortion due to EHV-1
most commonly occurs in the last trimester of preg-nancy.
Neurologic signs of EHV-1 are variable and
are reflective of a diffuse myeloencephalopathy includ-ing
ataxia (oftentimes more severe in the hind limbs),
urinary incontinence, decreased tail tone, and cranial
nerve deficits. Stranguria may be present and could be
mistaken initially as a mare coming into estrus. Horses
may or may not be febrile. Neurologic signs are typi-cally
symmetrical but can be asymmetrical. Neurologic
signs typically appear 6-12 days after exposure. The
neurologic signs may or may not be accompanied by
respiratory manifestations of the disease. Neurologic
signs typically stabilize in 2-3 days after the onset.
Mildly affected horses typically experience full recov-ery,
whereas those that become recumbent are much
4 | Veterinary Health Sciences
less likely to recover and are most often euthanized.
Differential Diagnoses
Diseases that should be included as differentials for
horses exhibiting neurologic signs consistent with
EHV-1 include equine protozoal myeloencephalitis
(EPM), eastern equine encephalitis (EEE), western
equine encephalitis (WEE), west Nile encephalitis
(WNV), cervical stenotic myelopathy or cervical verte-bral
instability, trauma, CNS abscess, rabies, and a
variety of toxicities.
Diagnosis
Spinal paracentesis is frequently performed in any case
of neurologic disease in the horse. Cerebrospinal fluid
(CSF) analysis in a horse with EHV-1 myeloencephalop-athy
may reveal xanthochromia and increased protein
concentration; however, the white blood cell count is
typically normal. The most rapid method for obtaining
a diagnosis of EHV-1 myeloencephalopathy is PCR on
a nasal or nasopharyngeal swab with matched whole
blood or buffy coat sample. It is important to note,
however, that there is the potential for false positive
results, as EHV-1 has been isolated from normal horses.
PCR testing of nasal swabs and blood will typically
test for both the DNA of EHV-1 and the marker asso-ciated
with neuropathogenic strains of EHV-1 (ORF
30). Although non-neuropathogenic EHV-1 has been
isolated from individual horses with neurologic disease,
the majority of outbreaks are associated with neuro-pathogenic
EHV-1. Virus isolation can be performed
on buffy coat, peripheral blood mononuclear cells, or
nasal swab.
Treatment
EHV-1 is a contagious disease, affected horses must
be appropriately isolated from other horses and came-lids.
People handling the infected horse must be aware
that they can spread the infection to other animals.
Supportive care is the mainstay of treatment including
nutritional and fluid support if indicated. Dependent
on the severity of ataxia, housing in a padded or well
bedded stall or even sling support with a hoist may
be necessary.
Controlling inflammation in the CNS is also an impor-tant
aspect of treatment. Antiviral treatment options
for neurologic EHV-1 have been investigated in horses.
For information regarding our recommendations for
treatment of EHV-1 please contact Drs. Todd Holbrook,
Lyndi Gilliam, or Lara Maxwell directly at OSU Center
Veterinary Health Sciences Veterinary Medical Teach-ing
Hospital (405) 744-6656.
Prevention
The only sure way to prevent EHV-1 myeloencepha-lopathy
is to prevent exposure. Efforts to prevent
exposure should include isolation of any suspect horses
and meticulous hygiene of personnel handling infected
horses including protective clothing and thorough hand
washing. Although EHV-1 is not likely to persist in the
environment for long periods of time it is good practice
to disinfect facilities and equipment exposed to infected
horses. There are a variety of available disinfectants
labeled for this purpose. While bleach is effective, it can
be easily inactivated in the presence of organic matter
so thorough cleaning prior to application is important.
There are several vaccines that protect horses against
the abortive and respiratory effects of EHV-1, however,
their protection against the neurologic form is contro-versial
and not well established.
Neurologic EHV-1 is a reportable disease in Okla-homa
and any suspicious cases should be reported to
the state veterinarian (405) 522-6131.
If you have questions regarding this article, please
contact (405) 744-6656.
Todd Holbrook, DVM, DACVIM
Associate Professor
Department Veterinary Clinical Sciences
Dr. Lyndi Gilliam, DVM, DACVIM
Assistant Professor
Department Veterinary Clinical Sciences
Alternative therapeutic
options for management of
chronic or recurring urinary
tract disease in the dog
and cat
Although standard, mainstream, accepted therapy
should always play a prominent role in treating patient
problems, alternative therapeutic approaches can be
valuable as adjunctive treatment options. Chronic
or recurring urinary tract disease may benefit from
Reprinting I f you would l ike to repr int an ar t icle please
contact the author at the l isted number.
Animal Health Update | 5
alternative treatment options as discussed below.
Probiotics and Prebiotics
Probiotics are live microorganisms, which when admin-istered
in adequate amounts, confer a health benefit on
the host. Prebiotics are defined as non-living, nondigest-ible
food ingredients such as oligosaccharides which
beneficially affect the host by selectively stimulating
the growth of and/or activating the metabolism of one
or a limited number of health promoting bacteria in
the intestinal tract. When a probiotic is combined with
a prebiotic for the purpose of producing a synergistic
effect, the mixture is referred to as a synbiotic. Probiot-ics
with or without prebiotics appear to have the most
potential for use in dogs and cats as nutritional aids
in the treatment and prevention of diarrhea. However,
other organ systems besides the gastrointestinal tract
may also benefit from the use of such supplements.
As a general rule, in order to be effective probiotics must
be stable in storage and provide large numbers of micro-organisms
after surviving gastric transit. In addition,
the microorganisms involved must be nonpathogenic,
nontoxic, non-resistant to antibiotics, and incapable
of being absorbed into the bloodstream following
consumption. Probiotics are frequently administered
with food. The microorganisms administered are only
transient residents of the GI tract. Consequently, when
probiotics are indicated, they must be administered
on a continuing basis to achieve the desired effect. If
given concurrently with an antibiotic, the probiotic
should be administered at a different time of day than
the antibiotic.
One synbiotic product (Azodyl®, Vetoquinol) has
been marketed as a preparation that will lower the
concentration of nitrogenous waste products (especially,
BUN and creatinine) in the blood of canine and feline
patients with chronic kidney disease (CKD) through
enteric metabolism of uremic solutes by the probiotic
organisms. This action, according to the marketing
company, helps prevent further kidney damage and
minimizes the clinical and biochemical consequences
of declining renal function. Azodyl® is administered
to patients as an enteric-coated capsule which contains
Enterococcus thermophilus, Lactobacillus acidophilus,
and Bifidobacterium longum as probiotic organisms
and oligosaccharides as prebiotic agents. Although
anecdotal and/or uncontrolled reports exist of reduc-tion
in azotemia in dogs and cats, the studies on which
the company’s claims are primarily based are nephrec-tomized
rat and minipig models. A clinical study of
cats with a placebo-control group has been conducted,
but the results, as-of-yet, have not been published. An
additional concern raised about efficacy of Azodyl®
lies in the fact that this product can be difficult to
administer to cats in its capsule form. Consequently,
the contents of the capsule are frequently sprinkled
on the feline patient’s food for administration, raising
the question of whether the probiotic agent will be
sufficiently active to be effective following GI transit.
As of this writing, although Azodyl® would not be
considered harmful to canine and feline patients with
CKD, its efficacy in regard to the manufacturer’s
claims is questionable. It has also been suggested that
probiotics may aid in the prevention of oxalate urolith
formation. Studies in humans and rats have shown a
decrease in urine oxalate concentration with coloniza-tion
of the intestinal tract with Oxalobacter formigenes,
a microorganism that facilitates degradation of oxalate
in the gut and leads to decreased excretion of oxalate
in the urine. The potential for use of this organism as
a means of reducing oxalate urolith formation in dogs
and cats has not been adequately investigated. Further-more,
the microbe which most consistently degrades
oxalate in the gut, Oxalobacter formigenes, is not
contained in the common probiotic preparations used
in the dog and cat.
Rhubarb
Recently the product Rubenal® by Vetoquinol has been
marketed for use in slowing the progression of chronic
kidney disease in dogs and cats. The product contains
a medicinal rhubarb, Rheum officinale, which report-edly
acts as an antifibrotic, anti-inflammatory agent
and, in various lab animal species, has decreased the
severity of experimental glomerulosclerosis and related
proteinuria. These actions have the potential to slow
down the progression of kidney disease and result in a
better quality of life. Kansas State University currently
has a study under way which is evaluating the effects of
6 | Veterinary Health Sciences
Rubenal® on feline patients with chronic renal disease
(CRD). Preliminary results have given some support
to the idea that the active ingredient does decrease
proteinuria and delay progression of CRD. The pill
administered is large and may be difficult to give to
some cats. Few side effects have been observed but
include vomiting and lethargy. Administering Rube-nal
® to patients with a history of calcium oxalate
urolithiasis should be avoided due to the potential for
increased oxalate excretion in the urine with rhubarb
consumption.
Cranberry Supplement
Cranberry supplement may help prevent recurring
bacterial urinary tract infection, especially infection
caused by E. coli. It probably does not acidify the urine
sufficiently to be effective in that way, but is thought
to help destroy the biofilm that helps protect certain
bacteria and allow them to attach to the uroepithelium.
It is not recommended for use in patients suffering from
or having a history of oxalate uroliths since cranberry
supplements may contribute to the excretion of oxalate
and favor oxalate formation because of its acidifying
qualities. It is best used concurrently with appropriate
antibiotic therapy and/or immediately after antibiotic
therapy has eradicated infection.
Cranberry juice can be used in both dogs and cats, but it
is bitter tasting and it is difficult to get a pet to consume
enough to accomplish the desired effect. UroMAXX™
by Animal Nutritional Products has cranberry extract
which is combined with other nutriceuticals for urinary
tract health and is an easy formulation for administer-ing
one to two times daily (I would recommend twice
daily dosing). Over the-counter cranberry extract can
be purchased as a health supplement. Dosing is vari-able,
but is generally recommended at approximately
10 – 20 mg/kg every 12 hours mixed with food.
Methenamine
For prevention of recurring urinary tract infection
(UTI), especially of E. coli, consider the use of a urinary
antiseptic once the UTI is appropriately treated with
antibiotics and under control (methenamine hippu-rate
– 500 mg/dog PO q12 hrs or 250 mg/cat PO q12
hrs). Methenamine will not be as effective with urease-producing
organisms like some strains of Staph, Proteus,
Enterobacter, and Pseudomonas which increase urine
pH; consequently, a urinary acidifier may be required
to be given concurrently to increase efficacy. The
compound methenamine hippurate has hippuric acid
added to help acidify the urine to aid in the hydrolysis of
methenamine to formaldehyde and ammonia. A urine
pH of < 5.5 is optimum for breakdown of methenamine.
Both formaldehyde and hippuric acid have nonspecific
antibacterial activity against various gram positive and
gram negative organisms. Methenamine may also have
antimicrobial activity against fungal organisms. It is
inadvisable to administer methenamine to patients
that are pregnant, lactating, dehydrated, or experi-encing
renal or hepatic insufficiency. Adverse effects
resulting from methenamine are primarily related to
nausea, anorexia and vomiting although dysuria may
be produced occasionally in response to high urine
formaldehyde concentrations.
Omega-Three Fatty Acids
Fatty acid supplements have become popular as thera-peutic
and preventative agents over the last several years
for a variety of disorders, including renal disease, cancer,
osteoarthritis, hypertriglyceridemia/hypercholester-olemia,
dermatitis, urogenital infections, and cardiac
disease. Although many of the claims of efficacy are
unproven, the potential for use as anti-inflammatory
agents seems to be supported both in theory and in
the clinical setting. The fatty acid supplements most
commonly used are omega-3 and omega-6 fatty acids.
Omega – 3 fatty acid supplements include eicosapen-tanoic
acid (EPA) and docosahexaenoic acid (DHA),
which are derived from oils of fish such as salmon,
trout and menhaden and from flaxseed. Omega-6
fatty acid supplements include linoleic acid (LA) and
gamma-linolenic acid (GLA), which are derived from
oils of seeds such as evening primrose, black currant,
and borage.
Fatty acid anti-inflammatory effect comes about
through the mechanism of cell injury and the subse-quent
inflammatory cascade that ultimately involves the
lipooxygenase and cyclooxygenase enzyme pathways.
When cell membranes are injured, phospholipids in the
membranes are broken down enzymatically, produc-ing
the omega-3 fatty acid, eicosapentaenoic acid, and
the omega-6 fatty acid, arachidonic acid. Metabolism
of eicosapentaenoic acid results in the formation of
products called eicosanoids that are non-inflammatory,
Reprinting I f you would l ike to repr int an ar t icle please
contact the author at the l isted number.
Animal Health Update | 7
non-immunosuppressive, and anticoagulatory (inhibit
platelet aggregation and clotting). Conversely, metabo-lism
of arachidonic acid produces eicosanoids that are
primarily pro-inflammatory, immunosuppressive, and
pro-coagulatory (cause platelet aggregation and clot-ting).
An exception to the production of inflammatory
eicosanoids from arachidonic acid is the formation
of the anti-inflammatory agent prostaglandin E1. In
addition, the omega-6 fatty acid di-homo-gamma-linolenic
acid (DGLA) produces eicosanoids that are
less inflammatory than those produced from arachi-donic
acid. Consequently, dietary supplementation of
omega-3 fatty acids and the omega – 6 fatty acid DGLA
would be expected to result in increased production of
non-inflammatory eicosanoids and decrease in inflam-mation
from cell injury.
Since fish oils can have an objectionable odor and occa-sionally
cause GI upset, flaxseed oil is sometimes used
as a source of omega-3 fatty acids. Flaxseed oil does
contain some omega-6 fatty acids, but is also a source
of the omega-3 fatty acid alpha-linolenic acid (ALA),
which can be converted to EPA and DHA. However,
dogs and cats are not thought to have good ability
to convert ALA to more actively non-inflammatory
components, limiting its usefulness as a dietary source
of beneficial omega-3 fatty acid. As stated previously,
supplementation of omega-3 fatty acids increases the
production of non-inflammatory eicosanoids, includ-ing
prostaglandins, which can be beneficial in reducing
inflammation in renal disease as well as improving blood
flow to the kidney through vasodilation. In addition,
such supplementation can decrease the production of
inflammatory eicosanoids. Published study data related
to chronic renal disease has been most supportive of
the benefits of omega-3 fatty acids in dogs although
some data exists suggesting potential benefits in chronic
renal failure cats fed diets supplemented with omega-3
fatty acids. Studies with chronic renal failure dogs have
indicated that those dogs receiving omega-3 fatty acid
supplementation had improved renal function and
fewer histopathologic lesions in the kidneys. Combin-ing
antioxidants with omega-3 fatty acids may have a
synergistic effect in benefiting pets affected by chronic
renal disease.
Although a wide range of doses (50 – 300 mg/kg/day)
can be found for omega-3 fatty acid supplementation,
(especially, EPA and DHA) doses around 100 mg/kg/
day have been suggested for canine and feline patients
with chronic renal disease. Many prescription diets for
pets have omega-3 fatty acids incorporated into the
formulation, including canine and feline renal diets.
Omega-6 fatty acids may be beneficial in combination
with omega-3 fatty acids, but an ideal ratio for supple-ments
has not been determined. Fish oil supplements
are usually in the form of capsules or liquids. Fish oils
can oxidize and become rancid, prompting manufac-turers
to add Vitamin E or to extract oxygen from fish
oil capsules in order to prevent rancidity. At higher
doses, fish oils may decrease platelet aggregation and
prolong bleeding time, increase fibrinolysis, and may
reduce von Willebrand factor. Gastrointestinal signs
such as nausea, gas formation, and diarrhea may be
associated with fish oil supplementation. Administer-ing
these supplements with food and increasing doses
gradually may help limit or prevent gastrointestinal
side effects.
Mary Bowles, DVM, DACVIM
Associate Professor, Veterinary Clinical Sciences
(405) 744-7000
Service Dogs and Veterinary
Medicine
Is your practice ready to meet the needs of a client with
a service dog? The popularity of these highly trained
dogs working to assist those with physical disabilities,
seizures, diabetes, hearing or visual impairments, and
even post-traumatic stress disorder (PTSD) is growing
by leaps and bounds. This growth is fueled in part by
the number of veterans returning home from war.
Service dogs are typically pure bred Labrador Retriev-ers
and Golden Retrievers though some organizations
will work with rescued dogs. Typically the animal is in
the training program from the age of eight weeks (or
younger if the organization has a breeding program)
to 2 years of age. While in training these valuable dogs
receive wonderful health care as a result of the gener-osity
of individual donors and veterinarians willing to
discount their services. Once a service dog has completed
8 | Veterinary Health Sciences
training and is ready for placement they obtain health
clearances for both hips and elbows.
Once a service dog is placed, the dog’s new partner is
responsible for health care. And the general practice
veterinarian will need to not only keep track of and
provide annual vaccinations, heartworm test, and
fecal check and prevention products but also keep in
mind the special needs of the dog and the client. For
example, a service dog must be clean and disease free,
not only to prevent their partner from getting any
infections but also to maintain their public access as
allowed by the Americans with Disabilities Act. Other
considerations to keep in mind relate to the disabled
individual – a wheelchair bound client, when faced
with a dog that starts having diarrhea, has additional
challenges beyond those of the general population and
a client with mobility problems usually relies heavily
on a service dog to maintain independence so the indi-vidual
must make additional plans if their service dog
has to spend a night or two at the vet clinic.
A veterinarian with a service dog
for a client will soon realize that
the abilities the dog has gained
though training will present some
interesting situations. Dogs that
are trained to open refrigerator
or kitchen cabinet doors and
drawers and fetch something
from that area can use his skills
to get into the type of trouble not usually seen with the
family pet. And service dogs are usually rewarded for
performing tasks with small treats – a partner with a
lot of love for his service dog may over treat so keep
an eye out for problems with obesity.
Being the health care provider for a service dog is deeply
rewarding. The experience will be fun, challenging,
and extremely interesting with endless opportunities
for creativity. And if there is a service dog organization
in your area get involved! These organizations always
need volunteers.
Barbara Miller, DVM, Director-Veterinary Care
Susan Hartman, Executive Director
Therapetics Service Dogs of Oklahoma
(918) 270-4226 or www.therapetics.org
Testing efficacy of Anthelmintic
combinations in goats done by LJ
Dawson and S Hart at the American
Institute of Goat Research at Langston
University. Results published in the
Journal of Animal Science 2010.
Gastrointestinal nematodes have developed a high
level of resistance to most commercially available
anthelmintics mitigating the effectiveness of chemo-therapy
for their control. One potential solution is to
use combinations of anthelmintics to control gastroin-testinal
nematodes. The purpose of this study was to
compare the relative efficacy of anthelmintic combina-tions
as compared to one anthelmintic alone. Boer x
Spanish does, over one year of age, were used in this
study. The study was done in late June on a group of
animals which were in late pregnancy or had recently
kidded. Haemonchus contortus would be expected to
be the dominant gastrointestinal nematode at this time
of the year. Does were given their treatments, fecal
samples taken and then fecal samples were taken 7
days later. Drugs used included albendazole (20 mg/
kg bwt), levamisole (12 mg/kg bwt) or moxidectin
(0.5 mg/kg bwt) and two – or three – way combina-tions
at the same dose, administered simultaneously.
All these treatments were given orally. Treatments
were 1) albendazole; 2) levamisole; 3) moxidectin; 4)
albendazole-levamisole combination; 5) albendazole-moxidectin
combination; 6) levamisole-moxidectin
combination; 7) albendazole-levamisole-moxidectin
combination; 8) copper oxide wire capsulres (2.0 g)
and 9) control. Each treatment was administered to
12 animals at random. Fecal egg counts were deter-mined
by a modificed McMaster procedure and fecal
egg count reduction (FECR) calculated. All animals
with an initial fecal egg count of less than 250 eggs per
gram (EPG) were deleted from the data with an aver-age
of 8.6 animals per treatment. Data were analyzed
by the SAS procedure. Comparisons of treatment were
analyzed with the Kruskal-Wallis test. The median
initial fecal egg count was 2,550 EPG.
Median FECR for treatments was 76, 39, 74, 85, 98, 98,
99, 28, and 14% for treatment 1, 2,3,4,5,6,7,8, and 9
respectively. Treatments 2 and 8 were not significantly
different from control (p > 0.10). Significant anthel-mintic
resistance was present since FECR for each
anthelmintic alone was less than 95%. Moxidectin
Reprinting I f you would l ike to repr int an ar t icle please
contact the author at the l isted number.
Animal Health Update | 9
and albendazole were significantly more effective than
levamisole (p < 0.06). Levamisole combinations with
moxidectin were more effective than levamisole alone
(p < 0.01). All anthelmintic combinations except for the
albendazole and levamisole combination were highly
effective. Anthelmintic combinations provide increased
efficacy over one anthelmintic and may be a useful
tool where there is significant anthelmintic resistance.
Goats Gastrointestinal
Parasite Control Basics
Internal Parasites are a major problem in small rumi-nants.
There are variety issues that can predispose
small ruminants to internal parasites including: stock-ing
rates, grazing instead of browsing, poor nutrition
including trace mineral deficiency; indiscriminate use of
anthelmintics; not using an effective dose of the anthel-mintic;
injectable route instead of oral administration
of anthelmintic, selecting animals with anthelmintic
resistance. All of these issues can contribute to the
development of parasite resistance of anthelmintics
on the market today.
FAMACHA is not a parasite control program but is
a tool in a parasite control program. Haemonchus
contortus (barber pole worm) is a common parasite of
small ruminants that causes anemia. You can measure
the extent or degree of anemia with the FAMACHA
card by comparing the color on the inside of the eyelid
of the conjunctiva to the color on the card. Treat all
animals with a FAMACHA score of 4 or 5 with an
effective anthelmintic and check again two weeks later
(other conditions can cause anemia like abomasal ulcer,
coccidiosis, lice and liver flukes etc.) If greater than
10% of the animals in a herd have FAMACHA scores
of 4 or 5 then consider treating animals that score 3,
especially does and ewes around lambing/kidding or
nursing; young animals and thin poorly conditioned
animals. In addition to the FAMACHA eye scores, a
parasite management program should include monitor-ing
of fecal egg counts periodically. Treat new animals
to a farm with at least two classes of anthelmin-tics
during quarantine period, and check a week
later to make sure their feces are free of eggs. This
procedure will minimize importing resistant intestinal
parasites. There are 4 classes of anthelmintics used
in goats to control parasites and few are approved
for use in goats. Therefore a producer should have a
Valid Client Patient Relationship or VCPR with a
veterinarian before they can legally use these products.
Approved anthelmintics in goats are Benzimidiazoles
and Tetrahydropyrmidines.
Benzimiazoles disrupt the formation of intestinal
microtubules of the parasites, thus preventing uptake
of glucose. Benzimidazoles available are: Albenda-zole
(Valbazen); Fenbendazole (Panacur, Safeguard);
Oxfendzole (Synanthic); Thiabendazole (Thiabenda-zole);
Mebendazole (Telmin). Due to the mechanism of
action of benizimadazoles, they can kill roundworms,
lungworms and tapeworms. Liver flukes are susceptible
to Albendazole. Because of the long history of use in
small ruminants, there is greater level of resistance to
Benizimidazoles.
Macrocyclic lactones stimulate the release of Gamma
Amino Benzoic Acid (GABA), which inhibits neuro-transmission
and paralyze the parasite, which leads
to death of the parasite by starvation. Macrocyclic
lactones available are: Ivermectic – Ivomec (injectable
or drench); Moxidectin – Cydectin (pour-on and inject-able);
Doramectin – Dectomax (injectable or pour-on);
Eprinomectin – Epirinex (pour-on). Macrocyclic lactones
are not effective against liver flukes and tapeworm.
Imidazothiazoles and Tetrahydro pyrimidines are cell
depolarizers or nicotinic agonists. They cause constric-tion
of the muscles, resulting in paralysis of the parasite.
The parasites are expelled alive. This class is effective
against roundworms. Imidazothiazoles available are
Levamisole and Tramisole. Tetrahydropyrimidines
available are Morantel or Rumatel and Pyrantel.
Guidelines – Use of Anthelmintics in
Goats:
• Use 1.5 times the sheep dose, because goats have
faster rate of passage and larger livers to metabo-lize
the drugs. Levamisole is used at 12 mg/kg,
and Cydectin is used orally at 0.5 mg/kg (pour-on
dose orally).
• Administer anthelmintics orally (back behind tongue)
10 | Veterinary Health Sciences
Oklahoma Animal Disease Diagnostic Lab
• Do not return the animal to the same pasture, rather
a new uncontaminated pasture 24 after treatment
• Observe withdrawal period before selling goat
• Pour-on anthelmintic products are ineffective &
anthelmintics should not be injected
• Hold goats off feed 12 hours and treat with anthel-mintic
and keep off feed another 12 or more hours
• Treat with anthelmintic twice, 12 to 24 h apart
especially benizimadozoles 20 mg/kg.
• Administration of anthelmintics in blocks, water or
feed not recommended because this often results in
animals not getting the correct dose and enhances
anthelmintic resistance.
Management Steps to Help Minimize
Anthelmintic Resistance:
• Animal selection (cull goats that consistently have
high fecal egg counts)
• Pasture rotation
• Co-species grazing
• Low stocking rates, etc
• Only treat goats that need to be treated as deter-mined
by FAMACHA eye color score
• Good nutrition – sufficient protein, energy, vita-mins
and minerals
• Treating and moving to clean pen or pasture
• Always administer an anthelmintic at appropriate
dose (see above)
• Avoid treating when pasture has few larva – late
summer or early fall.
• An effective anthelmintics will reduce fecal egg counts
by 95% at 7-14 days after giving the Anthelmintics
Lionel Dawson, DVM, DACT
Associate Professor, Veterinary Clinical Sciences
– OSU
Associate Professor, Research and Extension –
Langton University
Cytauxzoonosis
With the Oklahoma rains last month and increased
humidity the numbers of ticks are increasing and
consequently OADDL started seeing our first cases of
Cytauxzoonosis in cats for 2011. The onset of clinical
signs and ensuing rapid death often leads the owner
of the cat to suspect a poisoning. Clinically the cat is
presented with anorexia, pyrexia, dehydration, pallor,
icterus and maybe dark urine and dyspnea. On post-mortem
examination there is typically yellow fluid in
the thorax and abdomen, anemia, petechia, pulmonary
edema and splenomeglia.
Common Herbicide/Pesticide Questions
• What is the withdrawal time of MSMA? It contains
arsenic and will be on the plant until a good hard
rain washes it off.
• Can I spray Round-up around my kennel? Yes, it is
relatively safe, however there may always be dogs
that are hypersensitive to it. May emit toxic fumes
if burned. There is a 14-56 day grazing restriction.
• Can horses graze pastures sprayed with 2-4-D? Yes,
there is no withdrawal time for horses.
• Will herbicide mist kill the fish in my water garden?
Yes, fish are extremely sensitive to all chemicals that
can get in the water.
• Can I spray DEET on my animals? DEET is a
cholinesterase inhibitor and is synergistic with
other pesticides. Numerous cases of neurotoxic-ity
have been reported in cats and dogs associated
with the topical use of a product containing DEET
and the pyrethroid fenvalerate. Problems have also
been reported in horses wiped with DEET wipes.
There is a free 24-hour Oklahoma Poison Control
Hotline 1-800-222-1222
Sandra Morgan, DVM
Veterinary Toxicologist
Animal Health Update | 11
Equine Piroplasmosis
Since the identification of an index ranch in South
Texas in the fall of 2009 and subsequent identification
of infected horses associated with horse racing; many
states have instituted screening for Babesia caballi
and Babesia (Theileria) equi, the parasites responsible
for Equine Piroplasmosis, EP. The Oklahoma Horse
Racing Commission began requiring in July 2010 that
all horses entering tracks under their jurisdication would
require a negative test for EP. Because of this OADDL
was granted approval by the USDA to perform EP
testing. During the first year of increased surveillance,
2010, the USDA confirmed over 400 positive horses
in approximately 10 states; both Thoroughbred and
Quarter Horse racing animals. Annual testing for Piro-plasmosis
remains a requirement at all three Oklahoma
Pari-mutuel Race Tracks for 2011. In addition, some
other equine events have instituted mandatory test-ing;
most notably will be a negative test result within
six months for all horses entered in the four AQHA
World Shows in the summer/fall of 2011. OADDL has
performed 5793 Piroplasmosis tests since July of last
year and will continue to provide twice weekly test-ing
through the summer of 2011. Test submission to
OADDL requires the serum to be accompanied by a
fully completed, Oklahoma State Department of Agri-culture,
Food and Forestry Piroplasmosis Test Chart.
These forms are available through the State Veteri-narians
Office at 405/522-6142. Please take time to
familiarize yourself with the requirements and test
schedule availability for Piroplasmosis at the OADDL
website, http://www.cvhs.okstate.edu/index, then click
academics, then diagnostic laboratory.
Grant B. Rezabek MPH, DVM
Pathologist, OADDL
Trichomoniasis in Oklahoma
1/1/2011 – 6/7/2011
Half of the positive bulls testing for Tritrichomonas
fetus has really increased in the last couple of years
as surrounding states have passed requirements that
breeding age bulls entering their state have a negative
Tritrichomonas fetus test certificate. In January, 2011,
Oklahoma law required that breeding age bulls being
sold or entering Oklahoma must have a negative test
certificate for T. fetus. In 2010 there were approximately
2,800 Oklahoma bulls tested for T. fetus. 75 of the
bulls were positive for a 2.7% positive rate. So far in
2011 approximately 4,000 Oklahoma bulls have been
tested. 93 of the bulls have been positive for a 2.3 %
positive rate.
Half of the positive bulls in Oklahoma this year have
come from about 10 counties in the northeastern corner
of the state. This number does not necessarily mean
an increased incidence in this area since I have not
calculated the number of bulls tested in each county.
Also as veterinarians in northeastern Oklahoma have
found more of the disease, more clients have decided
they want to test for trichomonas even though they
may not be shipping a bull for sale which subsequently
results in finding more positive bulls. We are also find-ing
a lot of the disease in northwestern Arkansas and
that has resulted in the Arkansas Livestock and Poul-try
Commission enacting emergency rules similar to
Oklahoma.
I appreciate the work that veterinarians, extension
personnel, livestock market owners, cattlemen’s groups,
and many others have done in educating cattle producers
about this disease. I appreciate the producers them-selves
being cooperative and ethical in dealing with
their infected bulls and possibly infected cows by not
selling them in ways that could transmit the disease
to another’s herd.
Call if I can answer any questions or be of assistance.
Rod Hall, DVM
(405) 522-6126 or rod.hall@ag.ok.gov
Guest Speakers & Topics
Small Animal
Dr. Steven Marks
• Update on cardiopulmonary cerebral
resuscitation
• Fluid therapy for the trauma patient
• Diagnosis and management of respi-ratory
trauma
• Practical critical care techniques
Dr. Tiffany Tapp
• Pi t fal ls to avoid in veter inar y
dermatology
• Dermatology dilemma: resistant bacte-rial
skin infections
• Dermatology dilemma: resistant ear
infections
• New(er) drugs and treatments in veteri-nary
dermatology
Dr. Chelsea Makloski
• Small animal dystocia
• Pyometra management
Large Animal
Dr. Daniel Thomson
• Improving your client’s bottom line
through animal health & well-being
• Star ting stocker calves: health
management
• Starting stocker calves: nutrition
management
Dr. Tom Hairgrove
• Cow/Calf herd health
• Leptospirosis
• Vector borne disease
Equine
Dr. Peter Morresey
• What’s new in equine reproduction
and equine medicine?
• Managing the high risk mare
• The foal: the first 30 days
• The foal: the first 6 months
Dr. Betsy Vaughan
• Ultrasound non acute abdomen:
Chronic colic, fever of unknown origin
and weight loss
• The value of Pastern ultrasound
• Ultrasound-guided procedures: tips,
tools and techniques
• Equine ultrasound wet lab — hands
on instruction will include ultrasound
examination of the pastern and meta-tarsal
regions and ultrasound-guided
techniques (cadaver limbs).
Keynote Speaker — Dr. Guy
Palmer
• Global Animal Health
Cowboy Roundup — Thursday,
October 6 – 6:30 pm — Student Union
Alumni Class reunions — 1951,
1956, 1961, 1966, 1971, 1976, 1981, 1986,
1991, 1996, 2001, 2006
Distinguished Alumni Lunch
Friday, October 7 – 11:30 am.
Early August — watch your mailbox
for the Fall Conference Brochure; check
our website: http://www.cvhs.okstate.
edu/conference
Friday and Saturday, Oct. 6 & 7, 2011
Wes Watkins Conference Center
Thank you to our Cowboy Sponsors –
Bayer Animal Health, Merial, Pfizer, Boeh-ringer
Ingelheim
Oklahoma State University in compliance with Title VI and VII of the Civil Rights Act of 1964, Executive Order 11246 as amended, Title IX of the Education Amendments of 1972, Americans with Disabilities Act of 1990, and other federal laws and regulations, does not
discriminate on the basis of race, color, national origin, sex, age, religion, disability, or status as a veteran in any of its policies, practices or procedures. This includes but is not limited to admissions, employment, financial aid, and educational services. Title IX of the Education
Amendments and Oklahoma State University policy prohibit discrimination in the provision of services of benefits offered by the University based on gender. Any person (student, faculty or staff) who believes that discriminatory practices have been engaged in based upon
gender may discuss their concerns and file informal or formal complaints of possible violations of Title IX with the OSU Title IX Coordinator, Director of Affirmative Action, 408 Whitehurst, Oklahoma State University, Stillwater, OK 74078, 405-744-5371 or 405-744-5576 (fax).
This publication, Job# 3658 issued by Oklahoma State University as authorized by the Department Head, Animal Sciences, was printed by Career Tech at a cost of $1,220.00 2.5M/Feb/11.
Plan to join us for
Fall Conference
for Veterinarians