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

HEAVE LINE

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

STRANGLES - CLINICAL SIGNS

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.

Strangles

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

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 HERPES VIRUS

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 HERPESVIRUSTransmission

Inhalation – air born Fomites Carrier animal

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