2. EQUINE INFLUENZA

What is the causative agent of equine influenza?

Highly infectious RNA virus known as Orthomyxovirus.

What is a common cause of acute respiratory disease in horses?

Equine influenza.

What are common clinical signs of equine influenza?

Fever, cough, and nasal discharge.

Can equine influenza occur without clinical signs?

Yes, subclinical disease is possible.

How is equine influenza definitively diagnosed?

By viral detection methods such as PCR array or viral isolation.

What is a primary treatment approach for equine influenza?

Supportive care for infected animals.

What preventive measures are critical for equine influenza?

Biosecurity practices and vaccination.

When was equine influenza A/equine type-2 H3N8 first recognized?

In 1963.

Which countries are currently free from equine influenza?

New Zealand and Iceland.

What strains predominated in EIV outbreaks in Florida?

H3N8 clades 1 and 2 from the American lineage.

Who monitors the antigenic divergence of EIV strains?

The World Organization for Animal Health (OIE).

What diagnostic tests are used for equine influenza?

RT-PCR array, viral isolation, rapid tests, and serology.

When should nasopharyngeal swabs be taken for diagnosis?

Soon after the onset of illness, ideally 1-2 days.

What type of care do horses need if no complications from equine influenza develop?

Rest and supportive care.

How long should horses rest after fever due to equine influenza?

1 week for every day of fever, with a minimum of 3 weeks.

Fill in the blank: Exposure can be reduced by isolation of newly introduced horses for ______ weeks.

2

Fill in the blank: During an outbreak, sick horses should be isolated following standard biosecurity guidelines for ______ days after resolution signs in last newly infected horse.

21

Fill in the blank: Environmental contamination is possible and the virus can remain viable for ~______ days on fomites and in water.

2-3

Fill in the blank: Survival of the virus in aerosolized droplets lasts for a few ______.

hours

Fill in the blank: The current recommendation is that vaccines should offer protection against the strains of the ______ and ______ Florida lineage.

clade 1 and clade 2

Fill in the blank: Most influenza vaccines are inactivated, adjuvanted vaccines recommended primarily for ______ administration.

intramuscular

Fill in the blank: An intranasal modified-live influenza vaccine is designed to induce ______ antibody protection.

mucosal (local)

Fill in the blank: This intranasal vaccine is temperature sensitive and is not capable of replicating beyond the ______ passages.

nasal

Fill in the blank: Because the duration of protection provided by current vaccines is limited, booster injections for at-risk adult horses are recommended every ______ months.

6

Fill in the blank: Vaccination in an outbreak may be of value especially when performed early in the course of the outbreak and in horses previously ______.

vaccinated

Fill in the blank: The intranasal vaccine can achieve more rapid protection (~5–7 days) and thus is recommended for horses ______ before the outbreak.

unvaccinated

Fill in the blank: For effective biosecurity, sick horses should be ______ to prevent the spread of equine influenza.

isolated

Fill in the blank: The virus can survive on environmental surfaces for a few ______ to infect other horses.

days

Fill in the blank: Biosecurity practices aim to minimize ______ between infected and healthy horses.

exposure

Fill in the blank: The current vaccines' effectiveness against EIV may decline, necessitating ______ for at-risk horses.

boosters