"This is the first time in the world that we have found bird flu in cats and tigers," said Therapol Sirinaruemitr from Bangkok's Kasetsart University which tested the animals. "We found the H5N1 virus in the samples."
"One clouded leopard has already died and one white tiger is still alive and has recovered," he told a press conference, referring to animals kept at a private zoo east of Bangkok.
Two domestic cats have died of the virus. "They might have caught the virus from eating chicken carcasses or from live chickens that had bird flu," said Sirinaruemitr.
The three were among 15 cats living in a house located near an infected chicken farm in Nakorn Pathom, 60 km west of Bangkok, Sirinaruemitr said.
Meanwhile, Australian drug manufacturer Biota said in Sydney on Friday tests showed a treatment it developed can inhibit the deadly bird flu virus sweeping Asia.
Biota issued a statement through a government-funded science organisation CSIRO which said tests showed the drug Relenza helped inhibit the H5N1 flu strain.
"The tests, used to monitor virus sensitivity to drugs, have shown that the drug Relenza is as effective, in laboratory experiments, against this bird flu as it is against other strains of flu that affect humans," CSIRO scientist Jenny McKimm-Breschkin said.
"There is a direct correlation between enzyme sensitivity as measured by these laboratory tests and the ability of the drug to prevent the virus from multiplying."
"In the event that the disease does mutate into a form which can be passed from human to human, it is important to know that we already have treatment available"
McKimm-Breschkin said Relenza provided possible treatment if the worst-case scenario emerged.
"In the event that the disease does mutate into a form which can be passed from human to human it is important to know that we already have treatment available," she said.
Biota developed Relenza with CSIRO and has licensed the
product to GlaxoSmithKline, which pays royalties on the product to the Australian company.
Ban on Canadian poultry
The H5N1 strain has hit eight Asian nations, with weaker varieties detected in Taiwan, Pakistan and the United States. On Thursday, Canada also reported a less virulent strain in the western province of British Columbia.
The outbreak triggered a Japanese ban on Canadian chicken on Friday, despite Health Minister Pierre Pettigrew's assurances that the case on an isolated farm was being closely monitored and did not pose a risk to human health.
Thailand's hopes of declaring its bird flu outbreak over, and rebuilding its shattered poultry industry, were dashed earlier this week when it announced major new outbreaks had erupted across the nation.
"The possibility of infection from cats to people is very low. So do not panic"
The government is now preparing to announce more outbreaks of the virus.
Dhanirat Santivatr, the dean of Kasetsart's faculty of veterinary medicine, meanwhile, urged people not to panic.
"The possibility of infection from cats to people is very low... so do not panic," he added. The World Health Organisation has warned H5N1 could kill millions around the globe if it combined with a human influenza virus to create a new highly contagious strain transmissible among humans.
This situation could be exacerbated if pigs are found to carry H5N1, as experts say they are an ideal "mixing vessel" in which viruses swap genes, become more lethal or contagious and then leap to humans.