A study led by Peter Kirkland of the Elizabeth Macarthur Agricultural Institute at Camden, NSW, has revealed a number of Australian dogs kept near horses were affected by the equine influenza virus (EIV) during the 2007 outbreak of the disease.
The study said the first case occurred near a large stable, where a dog was reported as inappetant and lethargic with slight nasal discharge and a harsh, persistent cough.
In the following weeks, dogs in or near stables with infected horses, including dogs whose owners were handling infected horses or dogs that were only housed with infected dogs, were examined.
Nasal swabs and serum samples were also collected from dogs kept with horses at five other locations within a 60-kilometre radius of the first reported case. Of the 40 dogs examined, 10 had clinical signs consistent with influenza (anorexia, lethargy, and, for some, a harsh, persistent cough).
Each positive dog had been in close proximity to EIV-infected horses, but not always in direct contact. The mechanism of spread from horses to dogs remained unclear, and that all the dogs recovered.
“Although humans readily spread EIV from horse to horse, either directly during handling or by fomite transmission, human transmission of EIV to dogs that were not in the immediate vicinity of infected horses was not found,” Kirkland said.
“Similarly, lateral transmission was not found when infected dogs were transported and kept with other dogs in urban locations where there was no opportunity for contact with horses.
“Unlike the situation in the US where the virus has become adapted to dogs, there was no evidence of ongoing infection in Australian dogs.”
– AMELIA DALTON