“Influence of Time and Phenotype on Salivary Fel D 1 in Domestic Shorthair Cats”, 2019 (; backlinks):
Objectives: Fel d 1 is a major allergen that may affect humans sensitive to cat allergens, and it can be detected in the saliva and on the hair of cats. We studied the variability of salivary Fel d 1 in typical house cats (ie. neutered domestic shorthair cats) and the factors that could be associated with that variability.
Method: Saliva samples were collected from 64 cats, twice daily, every other day, for a year, at two locations (Missouri, USA, and Ontario, Canada). Salivary Fel d 1 levels were measured using an immunoassay. Correlations and linear mixed-effects model analyses were run to assess which factors significantly affected the Fel d 1 levels.
Results: Salivary Fel d 1 levels varied significantly both within and among cats. Cat averages over the year ranged from 0.4–35 µg/ml, and a higher average correlated with a higher SD (p <0.001). The first collection of the day tended to be higher than the afternoon collection (p <0.001). Sex, coat color or body size did not relate to cats’ average Fel d 1 production, but older cats tended to have lower salivary Fel d 1 levels (p <0.001). Fel d 1 levels from 4 samples were reliable in identifying cats producing stable low levels of Fel d 1.
Conclusion: We observed a wide and continuous range of salivary Fel d 1 production in domestic shorthair cats. In particular, a subset of cats had stable low levels throughout the course of the year, and they can be identified by analyzing a few saliva samples rather than their physical appearance.