Agriculture Minister Somsak Prissanananthakul has put a block on the movement of all cats in Angthong province to prevent the spread of a feline disease.
He insisted that infected cats could not infect human beings.
The Department of Livestock Development initially suspected cats were infected with feline rhinotracheitis virus (FRV), feline calici virus (FCV) or feline panleukpenia.
However, the department said it would identify certain types of viruses within five days.
So far, up to 855 cats have died in the province's Chaiyo district since January.
Meanwhile, residents have left 30 cats at temples, as they were scared of the disease.
The department has sent staff to survey other infected cats in nearby areas and to give them medical treatment.
Anybody finding animals dying from a disease should inform livestock officials in their province immediately.