April 4, 2008

An Australian survey of horse owners indicated a death rate of 5% among animals affected by equine influenza (EI).

The online survey was conducted by the Australian Horse Industry Council to gauge the death rate from the disease.

"There is an impression in many quarters that there have been large numbers of horse deaths during the EI emergency and that these have not been reported accurately," the council said.

The survey was an opt-in internet survey sent to 2987 horse owners, of which 1266 (42%) responded - roughly three-quarters from New South Wales and the rest from Queensland.

A total of 13,004 horses were on the properties of the survey respondents (an average of 10.3 equines per property).

Although only 12.5% of the 13,004 horses - 1622 animals - contracted the disease, this represented some 45.7% of all properties subject to the survey.

It was obvious from the findings, the council said, that if EI made it onto a property then all horse were likely to become infected.

Among the 578 infected properties, all horses became infected on 88.8% of them.

A majority of survey participants - 68.3% - said their horses did not need veterinary attention, and no complications arising from the disease were reported by 75.1% of respondents.

However, 13% reported performance problems when their horses returned to work.

The total number of deaths among those who reported infection - 86 - represented a death rate of 5% (86 deaths from 1622 infected horses).

Respondents reported that horses died across a wide range of age groups.

The most vulnerable group was less than a year old (34 deaths), with horses older than 20 (17 deaths) also over-represented.

"It must be emphasised that there are no corroborating post mortem findings to support the claims of the respondents on horse deaths due to EI," the council said.

"Nevertheless, given the large amount of publicity and horse-owner awareness of EI circulating in the horse populations of New South Wales and Queenland, the availability of veterinary attention throughout the EI emergency response, these observations are unlikely to be fabrications.

"Whether EI was the primary cause of death in these 86 horses remains unknown."