When you switch a dog from one kibble to another you really aren't just changing ONE ingredient (the chicken in your case). You need to compare ALL the ingredients in two foods and see what's different.
Having an allergy to a protein is rare in dogs. Yes, it does happen but you can't make that judgement using kibble.
Lauri & The Raw Fed Gang
Raw Dog Ranch
Winnie CGC - Corgi Mix
Chimanes Spice it Up Piquin (Kaynya) - Chinese Crested
Nator von Triton
HIC CGC (Mauser) - LC GSD
Piquins Some Like it Hot (Spike) – Chinese Crested
Piquins Too Hot To Handle - (Fuego) - Chinese Crested
Piquins Wasabi (Sabi) - Chinese Crested
Piquins Super Hot (Clark) - Chinese Crested
Banzai, Cloe, Mocha - Felines Extraordinaire
Neke, Tessa, Remi, Sadie, Riggs, Sasha, Tazer - DK, Mozart, Zoe - Gone but not forgotten