Scents would be a huge part of society. They are used to determine someone's health, their emotions, if they are attractive, etc. If someone has a bad scent, instincts would consider them 'wrong' or 'broken'.
So in an established bond (can be any paring, but I'm partial to FrUK/UKFr and RusAme/AmeRus) one of them, either Alpha or Omega (or Beta, if you wish) loses their scent through an accident or disease and the other one struggles to ignore their instincts that tell them that their mate is wrong and broken.
Bonus: the Alpha loses their scent and the Omega/Beta no longer wishes to have the pups they had been planning for. Bonus 2: the scent is lost due to a disease, and one of the reasons for rejection is that the disease would be passed to the other mate and any children they have
Any/Any - Omegaverse- in which scents are everything, and someone loses theirs
So in an established bond (can be any paring, but I'm partial to FrUK/UKFr and RusAme/AmeRus) one of them, either Alpha or Omega (or Beta, if you wish) loses their scent through an accident or disease and the other one struggles to ignore their instincts that tell them that their mate is wrong and broken.
Bonus: the Alpha loses their scent and the Omega/Beta no longer wishes to have the pups they had been planning for.
Bonus 2: the scent is lost due to a disease, and one of the reasons for rejection is that the disease would be passed to the other mate and any children they have