Second Australian Horse Tests Positive for Hendra Virus

A second Australian horse has tested positive for hendra virus and was euthanized, according to a bulletin from Ian Roth, New South Wales' chief veterinary officer. This case is not related to the Queensland horse that succumbed to the virus earlier in the week, Roth said.

"On Friday, July 1, 2011, samples from a horse were tested at the State Virology Laboratory at Elizabeth Macarthur Agricultural Institute, Camden, and found to be positive for hendra virus by PCR (polymerase chain reaction) testing of blood samples," Roth said in the bulletin. The newly confirmed case was located near Wollongbar on New South Wales' northern coast.

"The horse was reported as being off-color and feverish on June 28," the bulletin continued. "On Tuesday evening the horse was examined by a private veterinary practitioner who noted it had a high fever (40.8⁰C, or 105.4⁰F), significantly elevated heart and respiration rates, brick red mucous membranes, and was only passing scant feces. The horse also had neurological signs including slight ataxia, a wide frontal stance, and a lip droop.

"The horse was treated for endotoxemia and initially appeared to be responding to treatment. The horse was revisited by the private practitioner several times on June 29 and was euthanized very early in the morning of June 30 after developing severe neurological signs including apparent blindness."

The bulletin noted that there are no other premises with horses located near the horse's home farm, and the only other horse on the property appears to still be healthy.

Hendra virus (which has killed at least 40 horses since its discovery in the mid-1990s) has been known to yield numerous clinical signs in horses including respiratory distress, frothy nasal discharge, elevated body temperature (above 40°C, or 104°F), and elevated heart rate; however, authorities caution that hendra infection does not have specific signs.

Researchers believe that flying foxes (a breed of bat native to Queensland and New South Wales) are responsible for spreading the disease to horses; however, the exact mode of transmission remains unclear.

Earlier this year Australian researchers announced that a hendra virus vaccine is nearing completion, and it could be available to consumers within a few years if final testing is successful.

About the Author

Erica Larson, News Editor

Erica Larson, news editor, holds a degree in journalism with an external specialty in equine science from Michigan State University in East Lansing. A Massachusetts native, she grew up in the saddle and has dabbled in a variety of disciplines including foxhunting, saddle seat, and mounted games. Currently, Erica competes in eventing with her OTTB, Dorado.

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