strangles influenza equine herpesvirus equine viral arteritis recurrent airway obstruction (rao)
TRANSCRIPT
EQUINE RESPIRATORY DISEASES
StranglesInfluenza
Equine herpesvirusEquine viral arteritis
Recurrent airway obstruction (RAO)
RECURRENT AIRWAY OBSTRUCTION (RAO)
A.KA. HEAVES Formerly known as Chronic obstructive
pulmonary disease (COPD) Also known as “broken wind” Chronic, noninfectious respiratory
disease Thought to be an allergic airway disease
that causes bronchoconstriction & excessive mucous production
RAO - TREATMENT
House in a dust-free environment Outside is best (pasture)
Pelleted rations vs. hay Medications
No long-term scientific data to support any one treatment medically
http://www.youtube.com/watch?v=zJRoYWjVfbk
EQUINE VIRAL ARTERITIS (EVA)
1st isolated in Ohio in 1953 Togaviridae Reportable disease Most cases are subclinical
EVA VIRUS SURVIVAL
Inactivated by lipid solvents Inactivated by common
disinfectants & detergents Eva survives 75 days at 4c
Will survive in frozen semen
EVA - PREVENTION Vaccine available
All mares should be vaccinated three weeks prior to breeding
Modified live attenuated virus (in the US) Quarantine for carrier stallions Have stallions routinely tested
STRANGLES Streptococcus equi Name – some untreated horses sound
like they are strangling Most commonly affects horses 1-5
years of age, but can affect horses of any age
Worldwide Contagious
STRANGLES - PREVENTION
Vaccination available – however has the potential to cause the dz.
Isolation – recovered horses can remain contagious for up to 6 weeks after recovering from clinical dz.
EQUINE INFLUENZA VIRUS Orthomyxovirdae family
Genera: Influenza A, B, C, Thogoto and Isa viruses
Horses get Influenza A virus Influenza A also infects human beings,
swine and avian species On rare occasions will jump to different
species In 2000, an Equine Influenza A virus spread to
some dogs
EQUINE INFLUENZA VIRUS
Virus rapidly mutates, frequently producing different strains
Highly contagious Most common respiratory virus Spreads rapidly
“Explosive Outbreaks” 2 – 3 year-old horses most commonly
affected
EQUINE INFLUENZA VIRUS The lower respiratory track is primarily
affected in foals Can develop bronchopneumonia
The upper respiratory track is primarily affected in adult horses
EQUINE INFLUENZA VIRUS
Infected animals shed the virus for 1-8 days
Short incubation period Typically 48-72 hours, but can be as
short as 24 hours
EQUINE INFLUENZA VIRUSTransmission
Inhalation of virus – air born Direct contact w/nasal secretions Fomites – water buckets, feed bins,
etc.
EQUINE INFLUENZA VIRUSClinical Signs
Rapid onset exposed horses can get sick in 24 hours, 1-3
days is typical Lethargy, weakness, Decreased
appetite Fever – typically around 104, but can
exceed 106
EQUINE INFLUENZA VIRUSClinical Signs
Nonproductive cough Hacking cough
Mucopurulent discharge Retropharyngeal lyphadenopathy is not
uncommon Tachypnea
EQUINE INFLUENZA VIRUSDiagnosis
C.S. typically clear up in 7-14 days, however in more severe cases the cough can last up to 21 days
A history of “Explosive Outbreak” in barn or area
Fever for less than 5 days Mucopurulent discharge Demonstrate acute & convalescent antibody
titers 3-4 weeks apart
EQUINE INFLUENZA VIRUSTreatment
Symptomatic treatment NSAIDs Isolation if possible Antiviral medication Strict rest (stall)
- 1 week for each day the horse had a fever- Can be longer – up to 2-3 months- Hand walking only
EQUINE INFLUENZA VIRUSPrevention
Adequate nutrition Regular vaccination Regular exercise followed by adequate rest
between workouts Proper ventilation and sanitation in barn Quarantine new horses for two weeks
before introduction to herd
EQUINE HERPESVIRUSRhinopneumonitis
EHV-1 & EHV-4 are the two strains of importance
EHV-1 – Causes abortion, CNS, death The neurologic form of EHV-1 is called
Equine Herpesvirus Myeloencephalopathy (EHM)
EHV-4 – Respiratory signs
EQUINE HERPESVIRUSRhinopneumonitis
There are four separate syndromes Respiratory – most common Abortion storms – have become
increasingly rare Neonatal Neurologic
EQUINE HERPESVIRUS
Incubation period is typically 2-10 days
Rapidly spreads thru a herd High morbidity Low mortality (non-neuro form) Infected horses are typically ill for 4-
5 days
EQUINE HERPESVIRUSClinical Signs – Respiratory
Signs Runny nose Conjunctivitis Anorexia Malaise Dry cough Secondary bacterial infections Lymph node involvement – submandibular &
retropharyngeal Fever (102-106F)
EQUINE HERPESVIRUSTreatment
Usually self limiting Give antibiotics if secondary bacterial
infection develops Stall rest NSAIDS Isolation of infected animals Disinfect environment
EQUINE HERPESVIRUSClinical Signs – Neurological
Neurological signs appear as a result of damage to blood vessels in the brain and spinal cord associated with EHV infection.
Mild ataxia which may progress to complete recumbency – inability to rise
Inability to urinate Poor anal tone Recovery in 2-3 months if at all
EQUINE HERPESVIRUSTreatment - Neuro
Keep animal clean to prevent urine scalding Keep animal up – sling Keep plenty of clean bedding in stall Monitor for development of decubital ulcers
or urine scalding Keep tail clean from both feces & urine Supportive care
EQUINE HERPESVIRUSPrevention
Isolate new horses for 3-4 weeks Reduce stress Vaccine available, but effectiveness
for EHM is very limited Don’t share equipment between
horses at events
EQUINE HERPESVIRUSAbortion Storms
EHV can be asymptomatic in mares The mare is exposed to EHV during
gestation Then abortion storms occur weeks
to months later
EQUINE HERPESVIRUSAbortion Storms
The most infectious cause of abortions
¼ of all diagnosed abortions are due to EHV
The future breeding of the mare is not affected
Vaccinate according to schedule
EQUINE HERPESVIRUSOutbreak 2011
National Cutting Horse Association (NCHA) Western National Championship event in Ogden, Utah April 29 – May 9, 2011
State and Federal official contacted all owners and quarantined and monitored all animals thought to have been exposed at the event – 421 horses in total
EQUINE HERPESVIRUSOutbreak 2011
Once those exposed horses went back to their homes states and exposed other horses – 1,685 now had to be monitored
A total of 242 individual premises were affected
EQUINE HERPESVIRUSOutbreak 2011
EHV-1 in the neurological form (EHM) was implicated
A total of 90 confirmed EHV-1 or EHM cases have been reported in 10 states
EQUINE HERPESVIRUSOutbreak 2011
Of those 90 confirmed cases, 54 cases were at the Ogden, Utah event
Out of those 88 cases, 13 horses died from the disease or were euthanized by June 8th, 2011 10 were at the event, 3 were exposed
by animals from the event
EQUINE HERPESVIRUSOutbreak 2011
http://www.youtube.com/watch?v=JpgNzlnZAO8