equine viral diseases 1 - Steph Flashcards
equine influenza virus family
orthomyxoviridae
equine influenza viral structure
ssRNA virus, 8 segments, 11 proteins
name the influenza virus types
A,B,C,D
which influenza virus type infects equine
Influenza virus A (H3,H7)
equine influenza A1 is also known as
H7N7
equine influenza A2 is also known as
H3N8
what is the relationship between equine and canine influenza
equine influenza virus mutated to produce canine influenza virus
- H3N8 influenza virus closely related , flu virus jumped from horses to dogs (changed tropism)
which equine influenza suntype is common and crosses to canines?
equine influenza A2 - H3N8
hosts of equne influenza
horses, donkeys, mules, dogs
how is equine influenza transmitted
highly contagious aerosols (coughing etc.)
when is equine influenza virus excreted
excreted during the incubation period and for at least five days after the onset of clinical signs
who is able to shed equine influenza virus
vaccinated and infected horses are able to shed
incubation period of equine influenza virus
1-3 days
which cells does equine influenza target
ciliated epithelial cells and alveolar macrophages
where does equine influenza virus replicate
upper and lower respiratory tract epithelium
what are the consequences of equine influenza replication in the upper and lower respiratory tract epithelium
destruction of ciliated epithelium and secondary bacterial infection –> laryngitis, bronchitis and bronchointerstitial pneumonia –> pulmonary congestion and edema
what happens when there are equine influenza virus outbreaks among heavily pregnant mares
increased neonatal losses because of premature placental separation and dystocia causing fetal hypoxia –> may be related to high fever and not due to fetal infection
what causes equine pneumonia
equine influenza plus a secondary bacterial infection
how long until a horse can resume athletic activity after being infected with equine pneumonia
50-100 days
clinical manifestations of equine influenza
- high fever (39-41)
- depression (4-5 days)
- inappetence
- reddening of nasal mucosa
- conjunctivitis
- serous later mucopurulent discharge
- fatal in foals <2 weeks old
- characteristic harsh, dry paroxysmal cough
T/F: secondary bacterial infections are uncommon with equine influenza
FALSE!!! secondary bacterial infections are COMMON with equineinfluenza
in the absence of complications, how long does it take for a horse to recover from equine influenza
2-3 weeks after infection
morbidity and mortality of equine influenza
morbidity: 90%
mortality: low, 20%
diagnosis of equine influenza
Clinical signs: rapidly spreading respiratory infection, rapid onset, high fever, depression, cough
nasopharyngeal swabs
blood samples