Occurrence of infectious upper respiratory tract disease and response to vaccination in horses on six sentinel premises in northern Colorado.
BACKGROUND
Horses vaccinated against common agents of infectious upper respiratory disease (IURD) may not have detectable serum antibody and may not be protected from clinical disease.


OBJECTIVE
The objectives of this study were to 1) investigate the serological response of horses to vaccination against influenza virus (H3N8 and H7N7) and equine herpesviruses (EHV) in a field setting and 2) evaluate associations among vaccination status, serum antibody concentrations, and occurrences of IURD in monitored horses.


METHODS
In this study, horses on 6 Colorado premises were vaccinated parenterally against influenza virus and EHV, and serological response evaluated. Horses were monitored, and biological samples collected from individuals with clinical IURD and control horses.


RESULTS
Of 173 horses, 61 (35.3%), 21 (12.1%) and 4 (2.3%) seroconverted in response to vaccination against EHV, influenza virus H7N7 and influenza virus H3N8, respectively.


CONCLUSIONS
Outbreaks of IURD in study horses were associated with influenza virus H3N8 and Streptococcus equi infection, and serological response to vaccination with conventional products was poor.


CONCLUSIONS
These results confirm that horses may not respond with detectable serological responses to conventional vaccination against common respiratory viruses and, therefore, suggest that alternate methods of protecting horses against common respiratory viruses should be sought.
Mumford
E L
EL
Animal Population Health Institute, Veterinary Diagnostic Laboratory, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, Colorado 80523, USA.
Traub-Dargatz
J L
JL
Carman
J
J
Callan
R J
RJ
Collins
J K
JK
Goltz
K L
KL
Romm
S R
SR
Tarr
S F
SF
Salman
M D
MD
D000818:Animals; D000914:Antibodies, Viral / Q000096:biosynthesis / Q000097:blood*; D003120:Colorado / Q000453:epidemiology; D005260:Female; D004861:Herpesvirus 1, Equid / Q000276:immunology*; D006734:Horse Diseases / Q000453:epidemiology / Q000517:prevention & control* / Q000821:virology; D006736:Horses; D015994:Incidence; D009980:Influenza A virus / Q000276:immunology*; D008297:Male; D012140:Respiratory Tract Diseases / Q000453:epidemiology / Q000517:prevention & control / Q000662:veterinary*; D014611:Vaccination / Q000662:veterinary*; D014765:Viral Vaccines / Q000276:immunology
D000914:Antibodies, Viral; D014765:Viral Vaccines