Two flocks in Nezahualcóyotl that collectively included 49 birds are involved.

https://www.wattagnet.com/poultry-meat/diseases-health/avian-influenza/news/15768487/avian-flu-confirmed-in-fighting-birds-in-mexico

Roy Graber

October 2, 2025

mediosaudiovisuales | Pixabay

The presence of highly pathogenic avian influenza (HPAI) has been confirmed in two flocks of fighting birds in Mexico, according to a report from the World Organisation for Animal Health (WOAH).

Both flocks are in an urban area in Nezahualcóyotl, and the two affected premises are about 11 kilometers away from the nearest poultry production unit, the WOAH report stated.

One of the flocks included 40 birds, 27 of which had died. The other had nine birds, two of which had died.

According to WOAH, birds in the larger flock were exhibiting signs consistent with HPAI, including diarrhea, cyanosis in the crests and wattles, sudden death, pale livers and congested tracheas and lungs. The owner of those birds notified veterinary authorities in a timely manner, WOAH stated.

Birds in the smaller flock also exhibited signs consistent with HPAI, including respiratory distress, ruffled feathers, diarrhea, anorexia, prostration, death, hemorrhagic trachea and duodenal loop.

Depopulation activities took place at each property, as well as the following measures: quarantine, surveillance within and outside of the restricted zone, disinfection and official disposal of carcasses, by-products and waste.

WOAH listed these two flock infections in the same report as other cases of H5N1 HPAI, but it also reported that sequencing also detected genes corresponding to serotype H5N2.

The two fighting bird flocks were included in a WOAH report concerning the HPAI situation in birds classified as “non-poultry including wild birds.” WOAH also has an active report on instances of HPAI in commercial poultry, but the most recent case in that report was confirmed in May.

View our continuing coverage of the global avian influenza situation. 

To learn more about HPAI cases in commercial poultry flocks in the United States, Mexico and Canada, see an interactive map on WATTPoultry.com.