The incidents have raised concerns that the outbreak of bird flu in Ukraine may have spread to poultry farms producing meat for public consumption.
More than 32,000 birds have died or been culled on the three farms, which are in southern Crimea.
Bird flu was first identified in the Crimea in late November. In an attempt to control the disease, Ukraine's health authorities have killed some 40,000 domestic poultry owned by villagers.
Health officials said the symptoms in the infected birds at the poultry plants do not appear to be bird flu-related. However, laboratory results are needed before the virus can be identified more firmly.