The UK's chief veterinary officer said H5N8 avian flu has been discovered at a farm with 1,000 birds in Wyre.
Graeme Cooke said it has a "business link" to nearby farm Hy-Fly Game Hatcheries Limited in Preesall where the infection was confirmed on Tuesday.
Public Health England (PHE) said the risk to humans was "very low".
A 1.8 mile (3km) protection zone has been set up around the farm.
Defra said: "This case was proactively identified as part of a routine investigation of premises traced as a result of confirmation of the disease in Lancashire earlier this week.
"There is a business link between the two premises."
It said a number of birds have died with the remaining birds at the premises to be culled.
Defra said a full investigation is under way to determine the source of the infection.
Other related premises have been placed under restrictions which will remain in place until all investigations are complete.
The Food Standards Agency said bird flu does not pose a food safety risk for UK consumers.
There have been a number of other outbreaks of the virus including on a farm with 19,500 turkeys in Boston on Friday which was the third case of the H5N8 strain of avian flu in Lincolnshire in about four weeks.
The same strain has been discovered in birds in Settle, North Yorkshire, a swannery in Dorset and flocks in Carmarthenshire, south west Wales.
In December, the government introduced an avian influenza prevention zone, which lasts until 28 February, to help protect poultry and captive birds from avian flu after the strain was found in 14 European countries including Germany and France.
Bird flu has been found at a second pheasant farm in Lancashire, the Department for Environment, Food and Rural Affairs (Defra) has confirmed.