Clin Exp Vaccine Res.  2013 Jan;2(1):66-68.

Prolonged shedding of the canine influenza H3N2 virus in nasal swabs of experimentally immunocompromised dogs

• Hong M
• Kang B
• Na W
• An D
• Moon H
• Kim DJ
• Oh J
• Park SJ
• Poo H
• Kim JK
• Kim J
• Song D

Abstract

PURPOSE
The avian origin canine influenza virus H3N2 has been recently isolated and found to be currently in dog population in South Korea and China. The purpose of this study was to clarify the relationship between immunosuppressive glucocorticoids used in veterinary clinical practice and viral shedding pattern of influenza in dogs.
MATERIALS AND METHODS
Eight conventional beagle dogs were divided into control infection group and immunocompromised group. Dogs of both groups were infected with H3N2 canine influenza virus (2x106.0 EID50/0.1 mL). Dogs in immunocompromised group were given orally 3.0 mg/kg prednisolone for 7 days. Virus shedding was monitored using real-time polymerase chain reaction. After necropsy, histopathologic lesions were compared.
RESULTS
We found that immunocompromised dogs exhibited more prolonged (8 days vs. 13 days) and higher magnitude viral shedding than control group (peak titer of viral shedding 4.6 vs. 5.5 EID50).
CONCLUSION
Restricted use of immunosuppressive drugs in the clinical setting might help control the rapid spread of H3N2 through local dog populations.

Keyword

Canine influenza virus; Glucocorticoid; Immunosuppression; Viral load

MeSH Terms

Animals
China
Dogs
Glucocorticoids
Immunosuppression
Influenza A Virus, H3N2 Subtype
Influenza, Human
Orthomyxoviridae
Prednisolone
Real-Time Polymerase Chain Reaction
Republic of Korea
Viral Load
Virus Shedding
Glucocorticoids
Prednisolone

Figure

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  Fig. 1 Viral shedding in control (blue line) and immunocompromised (orange line) dogs after inoculation of the H3N2 canine influenza virus for 14 days. Data represent the mean ± standard deviation of 4 dogs per experimental group. p < 0.01. EID50, 50% egg infectious dose.

• 

  Fig. 2 Haematoxylin and eosin staining of a lesion from a control (A) and an immunocompromised dog showing very severe diffuse necrotizing suppurative bronchopneumonia (B). The latter died 7 days after inoculation of the H3N2 canine influenza virus (A and B, ×200).

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