Al A A
LARiG ANIMAL IA NMAGA
F UNIVERSITY of
from the Chief of Si
Happy New Year. Where did 2006 go? I suppose when we
are all busy and trying to make significant, positive changes,
the time flies. Already breeding season is right around the
corner and foals are already trickling in. The Hofmann
Equine Neonatal Unit at the University of Florida, under the
direction of Dr. Steeve Giguere, enters another foaling season
continuing to provide and constantly upgrade its advanced
veterinary services for critically ill foals. It is the only equine
NICU in Florida with board certified specialists in 10 separate
disciplines, includinginternal medicine, surgery, theriogenology,
anesthesiology, radiology, neurology, cardiology, dermatology,
clinical pathology, and pathology. Magnetic resonance imaging
(MRI) has been added to the specialized imaging modalities
which include videoendoscopy, ultrasonography, digital,
computed radiography, computed tomography, fluoroscopy,
and scintigraphy. The neonatal research performed here at UF
over the last several years has resulted in better ways to monitor
cardiovascular and respiratory function in foals, improving the
overall monitoring and immediate care of the critical neonate.
The clinician scholars performing this research are the same
ones who provide and oversee the care of our neonatal
patients. They and the staff are proud to be associated with
the most advanced neonatal intensive care center in Florida,
one which remains among the best in the nation and the world.
But we could not do it without our loyal referring veterinarians
and their clients. The more foals we see, the better we are. We
thank you for your support.
Dr. Maureen Longhas provided in this newsletter a summary of
the equine herpes outbreak in Florida. This article supplements
the information found on the front page of our college website
at www.vetmed.ufl.edu. We welcome the use of this website
as a portal link to your own website for veterinary continuing
education and/or the education of your clients. Dr. Long's
informative PowerPoint presentation is readily available.
While many were enjoying the holiday festivities, Dr. Jorge
Hernandez, Dr. Maureen Long, Dr. Rob MacKay, and Dr.
Dana Zimmel were hard at work developing a model for
the management of potential EHV-1 outbreaks in a referral
hospital setting These protocols have been implemented in
our hospital and will serve as a template for other infectious
disease outbreak threats. We are pleased to share them with
you through our website. Our protocols were based on the
AAEP guidelines, Equine Infectious Disease Outbreak: AAEP
Control Guidelines, found on the AAEP website at www.aaep.
org These AAEP guidelines were recently developed by the
AAEP task force chaired by Florida's own Dr. Mary Scollay.
The only thing that does not change is change itself One
would have bet that Dr. Rob MacKay would be Chief of the
Large Animal Medicine Service into the next century. Effective
January 1, 2007, Dr. Dana Zimmel will assume this role and will
do an excellent job, as Rob has done. But do not fear, we are
not losing Dr. MacKay. He merely wants to spend more time
in other activities, like t, I.hi i_ research, and clinical service.
Thank you Dr. MacKay for your excellent leadership and for
encouraging new leaders, like Dr. Zimmel.
We at the University of Florida Large Animal Hospital wish
each of you success in 2007. As always, we welcome your
S. _.~i. ri.., for how to serve you better.
Eleanor M. Green, DVM, DACVIM, DABVP
Professor and Chair, Chief of Staff
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NEIJROLOGIC AL EHV-I
WITH DR. MAUREEN LONG, DVM, MS, PIIl), DACVIM
Veterinarians with suspect cases of EHV-1 must
report to FDACS immediately 1-877-815-0034
Equine Herpesvirus 1 (EHV1) has a relatively short incubation
period (1-10 days) with a rapid onset of viral shedding that is
highest over the first three days of disease (Figure 1). Most
shedding is over by 10 days but shedding has been detected in
certain horses up to a month. Transmission occurs in several
ways and these include: 1) nose to nose contact 2) people through
contamination of hands and equipment 3) inanimate objects
such as water buckets, bits, clippers, etc, 4) aborted placenta and
The most important point is that clinically ill horses with
neurotropic EHV1 are capable of shedding high amounts of
virus and isolation of these horses and personal protection
consisting of gowns, boot coverings, head coverings, and
gloves to prevent horse-human-horse transmission must
be used. In an outbreak, most horses manifest as subclinically
infected but these horses still shed virus. The good news is that
herpesviruses are easily inactivated with quaternary ammonium
compounds or bleach (10%). Hand washing and soap/water
washing of equipment will minimize contamination. However,
without this, herpesviruses can persist in the environment
for a week and sometimes for up to 30 days.
EHV-1 Clinical Signs of Disease
Respiratory signs: May be minimal and of short duration and
increased rectal temperature may be the only clinical sign. Most
horses can have two fever spikes. The initial rise in rectal
Disease May Occur
Nasal Virus Excretion (Red)
1 2 3 4 5 6 7 8 9 10 14 28
Days post Exposure
Figure 1. Diagram of clinical signs, nasal virus excretion,
and viremia in horses with EHV-1 (E.P. Gibbs 2006)
temperature can be mild-101.5 to 102.50F and is often missed.
After the initial temperature rise, the horse can either be clinically
normal, develop nasal discharge, another increased temperature
(> 102.5), slight cough, abort, or, in a small number of cases
develop neurological signs.
Neurological signs: Horses become ataxic incoordinationn), can
be unable to empty its bladder, and may demonstrate weakness
of the tail. Some horses will become completely paralyzed; the
prognosis for these horses is poor. In a small number of cases,
horses can show abnormal mentation and develop cranial nerve
signs. Most horses become mildly to moderately neurologic and
stabilize rapidly. The neurologic signs can persist but most horses
are normal by 3 to 6 months after onset of clinical signs.
Abortion: Pregnant horses can experience spontaneous abortion
between 7 days and several months after exposure. The mare
will exhibit limited initial signs.
The take home message is that outbreaks of neurologic EHV1
can occur in populations of horses with a higher frequency of
affect horses (30-50%) and a higher incidence of mortality (30-
50%) in affected horses. This is the basis for concern and the need
to quarantine when these outbreaks manifest. In populations of
horses that break, usually 28 days is required in which no horses
leave the herd or are added to the herd to allow for activity to
minimize. In the individual horse that is affect and isolated, a 21
day period should be observed until testing and release.
Testing: UPON onset of clinical signs (temperature), a
nasal swab and a blood sample (purple top tube) should be
performed. Nasal shedding can be of short duration and the
samples should be taken the first day there is an increase in body
Vaccination: No vaccine is marketed with efficacy against
neurological signs associated with EHV1. In an outbreak
situation, vaccination must be weighed against the need for
accurate diagnostic information. Vaccination in general will
decrease post exposure nasal shedding of virus; both killed
) and modified live vaccines have demonstrated have this affect.
Currently killed vaccines offer protection against EHV4 which
is still important in certain populations of horses. However a
modified live vaccine would be expected to provide a faster
1 year onset of immunity especially in naive populations of horses.
Owners and veterinarians must decide which vaccine program
best fits the needs of a particular situation.
with Dr. Rob MacKay BVSc, PhD, DACVIM
As always at this time of the year, the Large Animal Medicine Service looks forward to the upcoming foal season. Although this
is our busiest time of the year, it is also the most rewarding. We believe that our infrastructure of equipment and support staff
combined with the collective expertise of our faculty clinicians and residents really does work well many critical foals are saved
that several years ago would have had little or no chance of survival. We like to think that the first equine neonatal intensive care
unit in the world (ours) is still the best.
The service is undergoing some rearrangements this spring. After ten years as service chief, I'm handing over the reins to Dana
Zimmel. Dr. Zimmel is known to most of you from her previous roles as a private practitioner in Ocala, equine extension
specialist here at the University of Florida, College of Veterinary Medicine, and an active participant in the leadership of FAEP
and AAEP. I am sure that Dana's varied background will bring a new and fresh perspective to our work and redound to the great
benefit of our service and clients. Steeve Giguere remains head of the ENICU; Chris Sanchez and I will continue our roles as
resident and beer coordinators, respectively.
This season we also have reorganized technical staff so that Heather Wells is exclusively attached to the Large Animal Medicine
service. Through Heather, we have instituted a system of clinician notification and follow-up phone calls that should improve
our efficiency and follow-through with clients.
This should be an excellent spring We welcome back those of you who have used us before and to the rest we say Happy
New Year and give us a try!
Diagnosis of Failure of passive transfer
of immunoglobulins in foals
with Dr. Steeve Gigu6re, DVM, PhD, DACVIM
Failure of passive transfer of immunoglobulins (FPT) is the
most common immunodeficiency disorder of foals. There
has been some controversy regarding the definition of FPT,
but the most widely recognized classification defines FPT as
serum IgG concentrations of less than 4 111 mg/dl after 24 h
Partial FPT is often defined as serum IgG concentrations
between 4 111 and 800 mg/dl whereas foals with adequate
transfer of IgG have serum concentrations greater than 800
mg/dl. The incidence of FPT (IgG < 41 1I mg/dl) in foals has
ranged between 3 and 20 %. Several studies have documented
a positive correlation between FPT and bacterial sepsis.
Assessment of colostrum quality
The three potential causes of FPT are production failure,
ingestion failure and absorption failure.
Insufficient production of colostrum can occur with a
premature birth where the mare has not yet produced
colostrum at the time of foaling Serious illness in the mare
during gestation or ingestion of endophyte-infected fescue
during the third trimester of gestation can also contribute
to a lack of colostrum production. Twinning, placentitis and
premature placental separation can cause premature lactation
in the mare. Mares with premature lactation prior to foaling
often leak colostrum, leading to low IgG concentrations at
the time of foaling Finally, the mare may produce an ample
volume of colostrum that is of poor quality with inadequate
Colostral immunoglobulin concentration can vary
widely between mares. Good quality colostrum has IgG
concentrations in excess of 3000 mg/dl. Immunoglobulin
concentration in colostrum can be directly measured by single
radial immunodiffusion. Alternatively, fairly accurate stall-side
estimation of colostral immunoglobulin concentrations can be
achieved by refractometry, specific gravity or glutaraldehyde
The equine colostrometer (orgensen Laboratories, Loveland
CO) is a modified hydrometer that measures the specific gravity
of colostrum. A specific gravity of >1.060 corresponds to an
IgG concentration of >3000 mg/dl.
A hand held refractometer (Bellingham & Stanley Inc.
Lawrenceville, GA) used to measure alcohol and sugar content
of wine can also be used. A reading of greater than 23% on the
sugar scale or greater than 16 on the alcohol scale corresponds
to IgG concentrations > 6000 mg/dl.
The ability of glutaraldehyde to form a solid clot in the presence
of gammaglobulins can also be used to estimate IgG content
of colostrum (Gammacheck C, Plasvacc USA, Templeton CA).
Formation of a solid clot in 10 min or less corresponds to IgG
concentrations > 3800 mg/dl.
Finally, a stall side immunoassay for colostrum evaluation has
recently been marketed (Midland Bioproducts Corp. Boone,
Continued on page 6...
Diagnosis of FPT
Assessment of passive transfer is important to accomplish
within the first 24 hours. This is the period of time when
the foal is most vulnerable to infectious organisms if
transfer of immunoglobulins has not been achieved. Serum
immunoglobulin status can be determined as early as 6 hours
after birth if the foal has nursed sufficiently. Generally,
immunoglobulin concentration is measured at 18-24 hours
at which time serum IgG concentration has reached its peak.
However, if there is concern or uncertainty regarding adequate
ingestion of colostrum, the foal should be evaluated before 12
hours such that oral supplementation of colostrum or an oral
immunoglobulin preparation can be given. Foals that develop
clinical signs of illness should have their immunoglobulin
concentration assessed to determine the need for therapeutic
intervention even if IgG was adequate during an earlier routine
Single radial immunodiffusion has historically been considered
the most quantitatively accurate test available but requires
an 18-24 hour incubation period. This long delay before test
results are available is the major disadvantage of this test as
rapid identification of FPT is imperative for timely therapeutic
intervention.More recently, turbidimetric immunoassays run
on routine chemistry analyzer have also been shown to be
Several stall-side tests or kits are available to estimate
immunoglobulin concentration in whole blood, serum or
plasma. Criteria for selection of a screening kit for FPT in foals
include overall accuracy, time necessary to perform the assay,
and cost (see table). Zinc sulfate turbidity (Equi Z, VMRD,
Pullman, WA), and glutaraldehyde coagulation (Gamma-
Check-E, Plasvacc USA, Templeton CA) tests are good initial
screening tests because they are relatively inexpensive and
results can be obtained in 5 min (glutaraldehyde coagulation)
to 1 h (zinc sulfate turbidity). These tests are fairly sensitive for
the diagnosis of FPT but they lack specificity. As a result, the
predictive value of negative test is very good, indicating that the
foal likely has adequate transfer of maternal immunoglobulin.
In contrast, a positive test does not necessarily indicate that the
foal has FPT and additional testing is warranted.
Many practitioners prefer the convenience and ease of use
of immunoassays. Both quantitative (DVM Stat, CAA,
WestBand, WI) and semiquantitative (Snap, Idexx Laboratories,
Westbrooke, ME; Foal IgG Midland Quick Test, Midland
Bioproducts Corp. Boone, IA) immunoassays are commercially
If you have questions about any of the information in this
article please call (352) 392-4700 ext. 4000.
Physical exam: All neonates should receive a physical examination within the first 8-24 hours of age. See the following table for
each specific parameter that should be examined including the normal values and possible reasons for abnormal observations.
Physical Exam Normal Abnormal
Attitude, Behavior Bright, alert, responsive Depressed, sleepy, hyperexcitable, seizures
Hypothermia- sepsis, prematurity, asphyxia; Fever-
Temperature 99.0 102.0 F indicates infection
Tachycardia- dehydration, sepsis, asphyxia, pain,
70-110 bpm, normal shock, fever; Bradycardia- septic shock, hypothermia,
Heart rate rhythm hypoglycemia
Capillary refill time < 2 seconds Prolonged CRT- dehydration, shock
Red/ injected-sepsis, endotoxemia; Pale pink- anemia;
Mucous Brown/orange- hemolysis, liver disease, sepsis;
membranes Pink and moist White/grey- shock
Pulse quality distal Strong, warm
extremities extremities Poor quality, cool limbs- hypotension, hypovolemia,
Tachypnea-stress, pain, pneumonia, shock, fever,
acidosis; Slow or irregular-asphyxia, shock,
Respiratory rate 30-40 breaths/min hypothermia, prematurity
Auscultation of Easily heard over the Crackles, wheezes, absent lung sounds-pneumonia,
lungs entire thorax atelectasis
Absent or increased borborygmi / abdominal
Gastrointestinal Borborygmi present distension- Enteritis, ileus, hypoxic damage to gi tract,
motility bilaterally meconium impaction, uroabdomen
Constipation-meconium impactions; Diarrhea- viral,
Feces, quantity, Pasty yellow or tan in bacterial, parasite induced; Bloody diarrhea-
color, consistency color, 2-4 times a day Clostridium or Salmonella enterocolitis
Suckle reflex 30 minutes after birth Absent or weak -sepsis, asphyxia, immaturity
frequently, USG < Decreased volume with dehydration, renal failure,
Urine 1.008 uroabdomen
Swelling or purulent discharge-umbilical infection; wet
Umbilicus Dry and small (urine)-patent urachus
Tearing, miosis, blepharospasm can indicate corneal
ulceration which can occur with recumbency or
Eyes, eyelids Clear cornea entropion
No evidence of Pain, heat, joint swelling or lameness can be caused
Joints lameness or distension by septic arthritis/physitis
If broken there may be increased RR rate, edema or
Palpation of ribs smooth, non-painful crepitus over thorax
Continued on page 8..
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FOAL MECONIUM IMPACTION FOAL STRAINING
Administration of Enemas: Meconium is digested amniotic fluid and cell debris. Most foals should pass meconium within
4 hours of birth. It is very common to administer an enema to prevent straining soon after the foal is born. Over the counter
enemas such as phosphate-based Fleet enemas are acceptable for this purpose. They are very simple to use and require
proper restraint of the foal while inserting the soft applicator into the rectum. As an alternative a stallion catheter can be used
to administer a soapy water enema using a few drops of Ivory soap in 200-500 mls of warm water. The rectum is check by
digital palpation first to remove hard feces. The tube is lubricated and inserted approximately 6-8 inches and the enema is given
by gravity. If the foal displays signs of constipation or straining without passage of meconium after 2-3 enemas veterinary
examination is prudent.
SUNKEN EYE DUE TO DEHYDRATION
Umbilical Care: If the umbilical stalk is bleeding after foaling a temporary clamp should be applied. Avoid using suture that can
serve as a nidus for infection. The use of strong solutions of iodine or tincture of iodine on the umbilical stalk is contraindicated
because it can cause severe scalding and necrosis of the skin. Dilute iodine 2"..; or 1 part 2% chlorhexidine and 3 parts sterile
water are recommended. Fill a 6 or 12 cc syringe case with the solution and hold it over the umbilical stalk for 30 seconds.
Dipping the umbilicus 1-4 times a day for 1- 2 days is adequate in a healthy foal. A spray bottle could be used as an alternative
to dipping. Inspection of the umbilicus for purulent debris, sudden enlargement, bleeding or urine should be part of the daily
routine by the farm manager for the first 3 weeks of life.
Practical use of antibiotics in the neonatal foal
Chris Sanchez, DVM, PhD, DACVIM
The main indications for antimicrobial use in the neonatal
foal include the prevention or treatment of sepsis and the
treatment of clostridial diarrhea.
Prevention of sepsis
Some of the most important strategies for sepsis prevention
include maintaining a clean environment, reducing the
potential bacterial load introduced during udder W. !i_.
ensuring rapid gastrointestinal intake and passive transfer
of immunoglobulins, and appropriate umbilical care. But,
if foaling is unattended or some of the above factors either
cannot be ensured or have been documented as inadequate, a
3-5 day course of antimicrobial therapy is often recommended.
If the foal remains healthy and afebrile, 3 days is typically
adequate, with a longer duration recommended for those foals
in which multiple risk factors have been identified. Broad-
spectrum antibiotics (ie. penicillin and an aminoglycoside) are
Treatment of sepsis
Antibiotics provide the basis of therapy for foals in which
bacterial sepsis is either highly suspected or confirmed by
culture. Initially a broad-spectrum bactericidal approach
must be used based on previous experiences and costs.
Antimicrobial therapy should begin immediately in any foal
in which sepsis is suspected. A minimum therapeutic course
of two weeks is recommended for bacteremic foals without
localizing clinical signs. If localizing signs, such as pneumonia
or septic arthritis, are present, a minimum course of 4 weeks
Agent Preparation Route Interval (h) Dosage (/kg)
Amikacm sulfate IV, IM 24 25 img
Ampicillm sodium IV, IM 6 22-25 mg
Cefotaxime sodium IV 6 40 mg
Cefpodoxime proxetll PO 8-12 10 mg
Ceftiofur sodium IV, IM 12 5 mg
Chloramphenicol palmitate PO 6-8 50 mg
Gentamicm sulfate IV, IM 24 6 6 mg (10-16 mg/kg
if dayss of age)
Metrondazole IV, PO 8-12 10-15 mg
Penicillin G sodium or potassium IV 6 22,000-40,000 IU
Penicillm G procame IM 12-24 22,000 IU
Few published veterinary reports discuss antimicrobial sensitivity
of organisms isolated from septic neonatal foals. A common
theme is that a lower percentage of gram-negative isolates are
sensitive to gentamicin relative to amikacin. Paradis reported
that 95% and 91% of gram-negative isolates were sensitive
to amikacin and cefotaxime, respectively, while sensitivity to
gentamicin and trimethoprim-sulfa was much lower.
Wilson reported cumulative sensitivity of all isolates from 33
foals to be >' ', .. for imepenim, ciprofloxacin, ceftriaxone, and
ceftazidime, 80-89% for amikacin and ceftizoxime, and only
70-79% for gentamicin and ceftiofur. Some organisms, such
as Enterobacter, Acinetobacter, Enterococcus, and coagulase-
positive Staphylococcus spp. have demonstrated substantial
At UF, antimicrobial sensitivity of organisms isolated from
foal blood cultures has varied somewhat by decade. In those
recovered from 2000-21 114, approximately 65% were sensitive
to trimethoprim-sulfa, 8' to ceftiofur, 811' to a combination
of penicillin and gentamicin, and 92-94% to a combination of
penicillin and amikacin or ampicillin with either amikacin or
Thus, based on available data, a recommended initial
therapeutic approach involves combining amikacin or a third-
generation cephalosporin with penicillin or ampicillin. The use
of aminoglycosides should be tempered in light of the foal's
cardiovascular and renal status. If a foal is severely hypovolemic
and azotemic, a safer initial choice would likely involve a
cephalosporin. If animoglycosides are used, serial monitoring
of creatinine every 2-3 days is recommended in order to
monitor for potential renal side-effects. A trend of increasing
serum creatinine concentration can be an early indicator for
nephrotoxicity, even without an overt increase above the normal
Unfortunately, the range of effective oral antibiotics is limited.
Due to significant resistance, trimethoprim/sulfa combinations
should not be used in septic foals without documented
sensitivity, and then only as a long-term option following initial
parenteral therapy. Cefpodoxime proxetil, a third-generation
cephalosporin available for oral administration, was recently
evaluated by Drs. Natalie Carrillo and Steeve Giguere.
Antibiotic Use in Foals from Page 9...
This drug was shown to be effective against 'I'" .. of Klebsiella
spp., Pasteurella spp. and 3-hemolytic streptococci.
Unfortunately, it was less effective for other bacteria
commonly associated with neonatal sepsis. Fluoroquinolones,
such as enrofloxacin, have an excellent spectrum of activity
against gram-negative and some gram-positive organisms
but have been associated with arthropathy in foals. Thus,
use of this agent should be reserved for those cases with
documented resistance to other antimicrobial agents, such as
with Salmonellosis and associated osteomyelitis, and informed
Treatment of clostridial diarrhea
Clostridial diarrhea can occur sporadically or in outbreaks.
A complete review of clostridiosis in foals is beyond the
scope of this article, but C. difficile-associated diarrhea can
range from mild to highly fatal, hemorrhagic or necrotizing
diarrhea to lactose intolerance in foals. C. perfringens (type
C)-associated diarrhea is typically associated with watery to
hemorrhagic diarrhea, often with signs of abdominal pain. If
clostridial diarrhea is suspected, therapy with metronidazole
should be instituted as early as possible and continued for at
least 7-10 days. In outbreaks of C. perfringens, therapy with
metronidazole should be instituted for at least 3-5 days in any
suspect foal, as rapid deterioration and death can occur prior to
the onset of diarrhea. Some cases of metronidazole-resistant
C. difficile have been documented. But, these cases are rare in
the Southeastern United States, and use of vancomycin should
be limited to severely ill, isolated foals in which resistance is
either highly suspected or documented.
More and more Floridians are venturing into the business of
raising llamas and/or alpacas for the harvesting of their wool.
There are some important concepts to remember regarding
pregnancy and parturition of these neonates, also known as
'crias'. The length of gestation for alpacas and llamas is 330
days and 345 days, respectively. It is recommended that the
dams receive routine medical care (vaccination, deworming,
and foot trims) no later than 60 days prior to the expected
deliver date to reduce the stress on the dam. As the time of
parturition nears, most dams will begin to develop an udder
within 1-3 days of delivery.
Once the fetal membranes have ruptured the cria is typically
expelled between 30 and 120 minutes. In addition, the complete
fetal membranes are expected to pass within 4-6 hours after
the cria has been delivered. Any delays in the delivery and/
or expulsion of the placenta should be considered a medical
emergency and the dam should be evaluated by a veterinarian
immediately. It is normal for the dam to have mucopurulent
discharge (lochia) exiting from her vulva for 3-4 days after
Continued on page 14...
SEPTIC ARTHRITIS IN THE NEONATE
WITH DR. TROY TRUMBLE, DVM, PHD, DACVS
Due to its immature immune system, neonates are more likely
to be susceptible to infection (sepsis). Systemically septic
foals have the tendency to infect other tissues, such as the
joints, via spread of bacteria through the bloodstream. Sepsis
should be considered in any lame foal < 1 month of age, but
identification of septic arthritis can be difficult. Thorough
daily musculoskeletal examinations are important because
many are weak and recumbent. Clinical signs include: joint
distention and/or heat, swelling around the joint, pain from
and/or restriction to passive movement, as well as focal pain on
palpation. Any joint or combination of joints can be involved,
but usually larger joints such as the stifle, hock, carpus and
fetlocks are most often affected.
When clinical signs I u t joint infection, it is important to
obtain radiographs of the joints of interest because infection
of the joint and growth plate region are closely related. If
the foal does not respond to therapy or regresses during
treatment, more radiographs should be taken and compared to
baseline. In addition, other more advanced diagnostic imaging
techniques such as ultrasound, nuclear scintigraphy (bone
scan), or magnetic resonance imaging (MRI) could be used to
identify infection prior to radiographic changes.
Examination of joint fluid helps confirm the diagnosis,
monitor effectiveness of therapy, as well as potentially identify
the causative agent. The presence of inflammation leads to an
increase in both total protein as well as white blood cells (WBC)
within the joint fluid. Usually joint fluid total protein > 4 g/
dl is indicative of severe inflammation that can be associated
with infection. When this is combined with a joint fluid WBC
count of > 30,000 ul, infection should be suspected. Joint
fluid should also be collected for bacterial culture to help select
the appropriate antibiotic.
Treatment can be difficult because many have multisystemic
disease. No one treatment is better than another, and a
combination of some or all probably leads to the best chance
for a successful outcome. Systemic antibiotics should be
started as soon as possible after the diagnosis is confirmed, or
even presumed. Since culture results generally take 48 hours
to obtain, initial antibiotic selection will need to be chosen
prior to having knowledge of the infecting organism. Broad-
spectrum antibiotics (usually penicillins combined with one
of the following: cefazolin, ceftiofur, gentamicin or amikacin)
should be chosen.
Joint lavage can enhance the effectiveness of systemic antibiotic
therapy by decreasing the number of organisms present within
the joint fluid so the antibiotic has the potential to be more
effective against the decreased numbers. In general, joint
lavage will need to be repeated within 48 hours if there is no
significant improvement in the amount of effusion or degree
of lameness. Once significant inflammation is present, fibrin
accumulates within the joint. Bacteria will congregate around
fibrin making it difficult to decrease the number of organisms
until fibrin is removed. At this stage, treatment needs to
become more aggress ive by debridement via an arthrotomy or
An additional approach is delivery of a high concentration
of antibiotics directly to the infected site since alterations in
tissue blood supply can limit the activity of the systemically
administered antibiotic in the actual infected tissue. To combat
the most common type of bacteria present in septic joints
aminoglycosides such as amikacin and gentamicin are routinely
used for intravenous or intraosseous regional perfusion. The
ideal number of regional perfusions that should be performed is
unknown, but repeat administration is often performed within
48 hours. Additional local therapies that are of some benefit
in septic joints include intra-articular antibiotic administration,
antibiotic impregnated beads, as well as indwelling drains.
The prognosis for septic joints in foals is poor to unfavorable
for survival. Early diagnosis and treatment via lavage and
debridement has been shown to be the most important aspect
of a successful outcome. In other words, early and aggressive
treatment is paramount for success. One study demonstrated
that 71% of foals treated within 2 days of the onset of clinical
signs survived whereas only 4% survived when treated after 2
days. However, the potential for future athletic function may
not be very good for those that survive, as only 3C-4:." .. of
Thoroughbred foals that had septic arthritis as a neonate started
> 1 race. Other factors that affect the prognosis include the
systemic status of the foal, number of joints involved, as well
as the extent of corresponding bony lesions.
Overall, the prognosis for survival and successful athletic
performance in foals with septic joints is guarded, but has the
best chance for success if treated early and ,- -., i- jl-- using
any combination of the methods described above.
Maintaining yearly foal production is important to broodmare
operations. Since income is generated from selling offspring,
maximal foal production ensures optimal economic
performance for broodmares. Income generated from
annual foal production also offsets maintenance and breeding
expenses incurred by the mare owner. Furthermore, many
breed associations impose a January 1 birth date. Breeding
for foal production early in the year allows the offspring to
command superior sales prices as yearlings or even two-year-
olds, and to remain competitive with its peers, again enhancing
economic returns (figure 1).
In order to maintain an annual production rate after foaling,
mares need to be bred soon after parturition. Mares typically
have an average gestational length of 333 to 342 days (range
320-360). Therefore, a mare must become pregnant within
one month post partum in order to continue to produce one
foal each year. Estrus generally begins 5-12 days after foaling;
hence, the terminology foal-heat or "9 day heat" is often
IFFBT OF TIME OF BIRTH ON PRICE
OF THOROUOHBR9eD FOALS
oo0000 -- T -,- 1, ,
Jan Feb Ma Apr Nay Jim Ju
MONTH OF BIRTH
USED WITH PERMISSION FROM DAN SHARP, PHD
UNIVERSITY OF FLORIDA
DEPARTMENT OF ANIMAL SCIENCES
The foal-heat usually results in ovulation, with most mares
ovulating within 20 days post partum. The average interval
from parturition to first ovulation approximates 10 days. Mares
that foal early during the season and do not become pregnant
on foal-heat, may enter seasonal anestrus (ovarian inactivity).
Pregnant mares exposed to artificial lighting (approximately 60
days) are less likely to show ovarian inactivity after foaling.
Given the short postpartum to conception interval required to
maintain yearly offspring, breeding mares in the foal-heat period
appears to be an attractive strategy to enhance reproductive
efficiency. Although pregnancy rates from mares bred on foal-
heat have been reported to be lower than for mares first bred
on subsequent estrous periods, it appears that there is little
impact on the overall pregnancy rates in those mares that do not
get pregnant on foal-heat and must be bred again. Therefore,
breeding on foal-heat offers the advantages of mantataining a
yearly production rate and reducing the possibility of seasonal
anestrous in early-foaling mares not bred on foal heat.
However, components such as uterine health must be considered
for successfully breeding mares on the first estrus after foaling.
In addition, mares that are hospitalized with a sick neonatal foal
on her side may be difficult to manage for optimal reproductive
Hospitalization may disrupt original breeding plans for the
mare, and visits to the breeding shed or ordering of transported
semen may be difficult to schedule. A sick neonatal foal is of
great concern to the owner, and breeding management of the
mare may seem less important at the time. However, if the mare
fails to become pregnant, or even if she is successfully bred
later during the season, the goal to produce one foal per year
From a strict financial standpoint, this will almost be as costly
for the owner as loosing the foal that currently is treated in
the neonatal unit. It is therefore, important to not only care
for the foal, but also provide optimal care and closely monitor
the mares' reproductive health during the critical post-partum
REPRODUCTIVE MANAGEMENT OFMAREs
MATS HT TROEDSSON, DVM, PHD, DACT, DECAR
MARGO L. MACPHERSON, DVM, MS, DACT
Uterine involution after parturition is a complex set of events
that dictates the readiness of the uterus for re-establishing
pregnancy. Involution occurs rapidly after a normal parturition.
Factors such as tissue remodeling, uterine contractility and
reduction in uterine size and fluid content are linked to
successful uterine involution. Rapid reduction in uterine length
and diameter occurs in the early postpartum period of the
mare. There is a positive influence of exercise on involution
of the uterus. Ultrasonographic measurements taken on days
6, 11 and 16 post partum (with the day of foaling designated
as day 1) revealed the mean diameter of the previously gravid
uterine horn reduced more rapidly in mares maintained on
pasture compared to mares confined to stalls. For mares that
are hospitalized with an unhealthy foal on their side, exercise is
limited with the mare confined to stall rest. In addition, she is
often not nursed by the foal. This is important, since nursing
may be another component in normal uterine involution. When
the foal is nursing, oxytocin is released from the pituitary gland
of the mare. In addition to being important for milk let-down,
oxytocin has an effect on uterine contractility. A failure of the
uterus to contract during the post-partum period will delay
Luminal contents (lochia) are discharged from the uterus
via the cervix during uterine involution. Lochial discharge is
typically seen as a vulvar exudate between days 3 and 6 post
partum. Color of lochia varies from red to reddish brown, but
sometimes can be yellowish when mucopurulent. Normal
lochia is not malodorous and is easily distinguished from
the fetid uterine discharge of mares with an acute uterine
inflammation. Uir ri i .i. p'-i.i. 1ii;, luminal fluid is frequently
seen in the first few days after foaling, but should not be
present at the time of breeding. We have observed that mares
that are confined to stall rest during the post partum period
retain intraluminal fluid longer than exercised mares.
Treatment Effects on Uterine Involution
Several treatments have been tried to hasten uterine involution
and/or improve postpartum pregnancy rates. These treatments
have included stimulating uterine contractions, removing
uterine fluid contents, and hormonal therapy.
Uterine lavage has been used in postpartum mares with
questionable benefit in hastening uterine involution or
postpartum pregnancy rates in normal mares. This is not
surprising, since the normal foaling mare has an efficient
mechanism for involution. Routine uterine lavage for normal
foaling mares is therefore, not be recommended. However,
if uterine involution is delayed or if intrauterine fluid
accumulation is present at the time of breeding, uterine lavage
should be beneficial.
Oxytocin or a prostaglandin analogue (prostalene) have
been used to speed up involution in attempts to improve
postpartum pregnancy rates, but the effect in normal mares
has not been consistent. Therefore, treatment of the normal
foaling mare may not alter postpartum events because natural
mechanisms are already contributing to rapid repair of the
uterine environment. The effect in mares that experience
abnormal parturient events, mares that are confined to stalls
because of health problems to the mare or foal, or aged mares
with compromised uterine clearance, might be more profound.
Mares with foals that are too weak to nurse, are routinely
treated with oxytocin at UFVMC.
Factors that will decide if a mare can be bred on foal-heat:
Periparturient problems, including dystocia or retained
placenta, have been shown to slow the uterine involution rate
and delay the first postpartum ovulation. In addition, mares
experiencing a dystocia frequently suffer trauma to the genital
tract that will impair reproductive soundness. This category of
mares would not be suitable for breeding during foal-heat.
Day of Ovulation Post partum
The day of first postpartum ovulation has long been the
benchmark for determining if a mare is ready to breed in the
foal-heat period. Historically, pregnancy rates have been higher
in mares that have ovulated after day 10 postpartum. Recent
data from Texas A&M indicate that the day of first postpartum
ovulation may not be a definitive factor for success in foal-heat
breeding. Other factors, such as inherent fertility of the mare,
uterine health, and exercise may be as important as the day of
ovulation for mares bred on foal-heat.
Presence of Intrauterine Fluid
The presence of intrauterine fluid at the time of foal-heat
breeding will significantly interfere with a mare's ability to
CONTINUED ON PAGE 14...
Strategiesfor Breeding Mares on the First Estrus
Treat each mare individually, and pay extra attention
to the uterine health of mares at risk of
delayeduterin involution (e.g. hospitalized mares).
Examine the mare beginning day 5-8 post partum
Breed only mares that do not have intrauterine fluid
Practice good breeding management protocols with
Consider post-breeding treatment in at-risk mares.
Uterine therapy should not be necessary in the normal, post-
foaling mare with unlimited access to exercise and a suckling
foal. Mares that show abnormal retention of uterine fluid in the
postpartum period may benefit from post-breeding treatment
with oxytocin and/or uterine lavage.
An Alternative Postpartum Breeding Strategy
Many mares that are hospitalized during the immediate post-
partum period, experience delayed uterine involution and are
not suitable to be bred during foal heat. For these mares, an
alternative breeding strategy can be implemented in order to
maintain an optimal foaling interval.
Examine the mare daily, beginning day 5-8 post
Determine the day of ovulation.
Administer prostaglandin (PGF2%) 5-6 days after
ovulation for luteolysis.
Monitor the mare for signs of estrus and breed.
It is thought that a short-cycling protocol allows the uterine
environment more time for involution. This protocol provides
a shorter interval to breeding than breeding on the second
naturally occurring postpartum estrus (typically around day
30). The success of this breeding strategy is still dependent on
the reproductive management of the mare during the first 7-10
days after foaling.
In conclusion, with a target on a breeding interval of one
foal per year, special attention must be directed towards the
reproductive health of mares that are hospitalized with a
sick foal during the immediate post-foaling period. Close
monitoring of uterine involution and follicular development in
combination with sound breeding decisions will optimize the
mares' reproductive performance. Considering criteria such
as parturient events (dystocia, retained placenta, reproductive
tract trauma), uterine involution, physical examination findings
and good breeding management, breeding during foal heat, or
short-cycling of the mare after foal heat can result in favorable
pregnancy rates in a highly efficient manner.
Managing Llama and Alpaca Neonates continued from page
Evaluation of the cria shortly after birthing is important. The
cria should be evaluated for birth defects such as contracted
tendons, chloanal atresia, and wry face, Chloanal atresia is a
common birth defect that affects the nasal passages of llamas
and results in severe difficulty in breathing. Hence, respiratory
rate and effort should be closely monitored. Equally important,
cardiac abnormalities are relatively common in crias and may
result in exercise intolerance and/or respiratory distress. Any
cria that is having difficulty breathing (open-mouth' ., irhii _i,
or appears weak should be evaluated by a veterinarian
Some important post-birthing events that should be
Standing within 2 hours of delivery
Nursing within 4 hours of delivery
Rectal temperature: 37.7-39 C
Pulse rate: 60-90 beats per minute (bpm)
Respiratory rate: 10-30 bpm
Muconium (first feces )passed within 2-4
hours of delivery
Finally, it is very important to ensure that the cria receives
adequate immunoglobins from the dam's colostrum and
appropriate measures are taken to treat the umbilical stump.
Failure of passive transfer in newborn crias is a complication
that can result in critical illness and sometimes death. Crias
should consume more than 10 percent of their body weight
during the first 24 hours of life. For a 10kg llama, 1kg or 1 liter
of colostrum is required. If there is any question regarding
the status of passive transfer, a veterinarian should collect
blood from the cria to verify the levels of immunoglobins in
the cria's serum. The umbilical stump should be treated three
times during the first 24 hours postpartum with a dilute (0.5%)
clorhexidine, followed by two times per day for the next 7 days.
Failure to properly treat the umbilical stump may result in a
localized infection that can become systemic.
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IT'S BLUE SKIES AND
CLEAR EYES FOR LULU
by Sarah Carey
The 3-month old Miniature Jersey cow, owned by Peter
Petres of Bradenton was born with cataracts but now has the
gift of sight, thanks to the UF Veterinary Medical Center's
"She came in on Tuesday, Oct.,10th, had surgery the next day
and went home the following Monday so that we could keep
her confined and give her intravenous medications," said Dr.
Caryn Plummer, assistant professor of ophthalmology, who
served as the attending veterinarian on the case along with Dr.
LULU, A 4-MONTH-OLD MINIATURE JERSEY COW, ON OCT. 11
PRIOR TO HER RELEASE FROM THE UFVMC. LULU HAD
SUCCESSFUL SURGERY TO REMOVE CATARACTS IN BOTH EYES
OCT. 10 AND CONTINUES TO RECUPERATE WELL AT HOME.
"We did cataract extraction by way of a procedure called
phacoemulsification -- the same procedure that we use to
remove cataracts in dogs and that human ophthalmologists
use to remove cataracts in humans," Plummer said. "The cow's
lens is much larger, though."
Plummer said Lulu was "doing great" and had returned to the
VMC two weeks after surgery for a recheck. "She's healing
beautifully," Plummer said. "Her vision will never be normal,
because we do not have an intraocular lens available for use
in cows, since there is no commercial market for such things.
Even so, her vision will certainly be better than before the
cataract removal." Congenital cataracts are rare in large animals,
Plummer said. "But it's even more rare to have a situation in
which we are able to treat them, since most cows would be
culled because of them."
For Petres, the latter was never an option. In fact, he and
his wife, Tracy, had been looking for a Miniature Jersey cow
because they thought the breed would be perfect for their five-
acre ranchette near Sarasota. "Over the years, I kept tabs on
breeders, availability, prices and general information," Petres
said. "This past June, I saw that a breeder had a heifer cow
born with congenital cataracts. It tugged at my heartstrings,
what the outlook might be for this calf, so before I even spoke
to the breeder, I contacted UF's VMC to see what might be
Told that cataract removal was indeed possible and would give
Lulu a better quality of life, Petres contacted the breeder and
arranged to pick Lulu up. "She stayed at a friend's place along
with four horses while I finished a new barn and introduced
Lulu's companion, Sammy, to his new surroundings," Petres
said. "With the cataracts, Lulu had a limited routine on her
own, so I made it a point to walk her as often as possible with
a halter. There was no problem giving her attention where she
was r i-i-, as she is so cute and everyone loved her. She was
brushed and handled often and seemed to thrive."
A few weeks before Lulu's operation, the Petreses moved her
to her new home and introduced her to Sammy. "The two hit
it off right away," Petres said. After he dropped Lulu off at
UF's VMC, everyone was "compassionate and professional,"
but that didn't keep Petres from being anxious.
"Dr. Blackwood called daily with Lulu's progress and the next
week I brought her home," he said. "Our first insight into her
new-found sense was when we arrived home after dark. Sammy
would have nothing to do with the alien sporting the satellite
dish (Elizabeth collar) around her neck! He was snorting,
kicking and running around."
Lulu, however, seemed quite content to be home.
"I guess in her previously dark world, everything seemed
normal," Petres said, adding that Sammy sniffed Lulu through
the stall slats her first night home and finally calmed down.
"The next morning when I brought Lulu out of the stall into
the pasture, it was her turn to kick and run," Petres said. "She
ran around in circles, stopped to sniff poles, sniff me, and then
went back to running while Sammy was looking and wondering
what all the fuss was. Apparently, things looked different to
Lulu in daylight."
He added that on the morning of Nov. 2, he took Lulu's collar
off for good. "I tried to sneak up on her this afternoon, but
she saw me halfway across the field, got up, stretched her back
and trotted over to me," Petres said. "I got big, sticky cow licks.
Life is good at the Petres Ranch."
UFVMC ON THE SCENE
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