Page 5 - Equine influenza e-Book

Client history

• Dry, harsh cough Coughing.
• Inappetence.
• Nasal discharge Nose: nasal discharge.
• Ocular discharge Eye: ocular discharge.
• Exercise intolerance.
• Dyspnea.
• Limb edema.
• Contact with affected horses.
• Travel.

Clinical signs

• Dry harsh cough Coughing.
• Ocular Eye: ocular discharge and nasal discharge Nose: nasal discharge (serous → purulent with
secondary infection).
• Submandibular lymphadenopathy.
• Pyrexia.
• Abnormal lung sounds: wheezes > crackles Thorax: auscultation predominantly caudal and caudoventral
lung fields.
• Corneal opacity.
• Limb edema.
• Weight loss may be more severe in animals maintained on the usual exercise regimen.

Diagnostic investigation

Virology

• Virus isolation from nasopharyngeal swab Pharynx: nasopharyngeal swab in amniotic cavity of
embryonated hens' eggs or canine kidney cells.
• Virus detected by hemagglutination with chicken erythrocytes; also immunofluorescence on tissue
impressions, nasal swabs.
• Virus identified by hemagglutination inhibition using specific antisera.
• Slow and labor intenstive but vital for identifying new strains.

Antigen detection

• From naopharyngeal swabs.
• ELISA for nucleoprotein (UK) or Real Time-PCR for virus specific nucleic acids (Australia outbreak).
• Significant conservation of nucleoprotein therefore human kits like Directigen Flu-A can be used-rapid
but not as good as RT-PCR.

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