"There could be many reasons why those birds died. So I don't think that there's any need for panic," John Rahael, the health minister, said on local television on Tuesday, adding that authorities were investigating.
Preliminary tests showed the cause of the deaths might have been aspergillosis, a fungal infection, Jarette Narine, the agriculture minister, said.
"Confirmation of this diagnosis is expected later with analysis of samples taken at the site and the submission of a report by the investigating team," Narine said.
The mass chicken deaths have occurred since Thursday in half a dozen large farms around Cumuto, 40km east of the capital of Port-of-Spain, according to local farmers.
Farmer Lee Black said 38 birds had died overnight, and more than 1000 of his 7000 birds have died since Thursday. He said other farms in the area had been similarly affected.
Turkey has reported at least 14
human cases of bird flu
Dr Bhim Ramoutar, the Agriculture Ministry's chief veterinary officer, who inspected the farms, said he did not believe the chickens had the bird flu virus.
An Associated Press reporter saw dozens of dead chickens scattered around the fields. Farmers said they had buried hundreds of dead chickens and were quarantining the sick ones.
Those chickens have swollen stomachs, watery eyes and beaks, a lack of appetite and greyish blue skin, they said.
Samuel Jutzi, head of animal production and health services at the UN's Food and Agriculture Organisation, said the symptoms resembled those of bird flu, but also could fit a range of other diseases.
He said it usually took laboratories two days to determine what virus or disease had led to a bird's death.