Bastien, B.C. et al.
2019
Journal of Feline Medicine and Surgery

Fel d1 in saliva and on hair of cats is a main allergen that humans allergic to cats are sensitive to. Evaluating saliva samples twice a day on alternate days for one year in 64 neutered domestic shorthair cats showed that levels varied. Levels were lower in the afternoon, in older cats and some cats had consistently lower levels thoughout the year, but could not be identified based on coat color, body size or sex. Implication would be that adapting an older kitty or testing saliva samples can help matching human with a shorthair cat producing low levels of allergen.