Influence of time and phenotype on salivary Fel d1 in domestic shorthair cats

Abstract

Objectives Fel d1 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 d1 in typical house cats (ie, neutered domestic shorthair cats) and the factors that could be associated with that variability. Methods 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 d1 levels were measured using an immunoassay. Correlations and linear mixed-effects model analyses were run to assess which factors significantly affected the Fel d1 levels. Results Salivary Fel d1 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 d1 production, but older cats tended to have lower salivary Fel d1 levels ( P <0.001). Fel d1 levels from four samples were reliable in identifying cats producing stable low levels of Fel d1. Conclusions and relevance We observed a wide and continuous range of salivary Fel d1 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.

Reduction of active Fel d1 from cats using an antiFel d1 egg IgY antibody

“…Baseline Fel d1 was highly variable among cats, indicating that some cats naturally produce less Fel d1 than others. Week to week variation was higher in cats with high Fel d1 production compared to those cats with lower Fel d1 levels, consistent with what has been observed previously . In that study, cats with naturally low salivary Fel d1 levels remained low over the course of a 1 year study, while high producers were highly variable in the levels of their salivary Fel d1, yet remained high on average.…”

“…Week to week variation was higher in cats with high Fel d1 production compared to those cats with lower Fel d1 levels, consistent with what has been observed previously. 4 In that study, cats with naturally low salivary Fel d1 levels remained low over the course of a 1 year study, while high producers were highly variable in the levels of their salivary Fel d1, yet remained high on average. In this study, both the mean and the variation were reduced in the high producing cats, and the mean aFel d1 was reduced even in the lower Fel d1 producing cats.…”

“…As may be expected, there is a strong correlation between salivary concentrations of Fel d1 and the Fel d1 found on cat hair. 4 In addition, its small size and structure allows Fel d1 to be easily and continuously airborne for long periods of time making it one of the easiest allergens to inhale. 5,6 Its molecular structure also allows it to adhere to fabrics, carpet and upholstered furniture.…”

Keep the cat, change the care pathway: A transformational approach to managing Fel d 1, the major cat allergen

“…All cats produce Fel d 1 regardless of breed, age, hair length, sex, housing (indoors vs outdoors), or body weight; there are no allergen‐free or hypoallergenic cats . Fel d 1 production varies widely among individual cats and may vary widely throughout the year in the same cat .…”

“…3,13,14 All cats produce Fel d 1 regardless of breed, age, hair length, sex, housing (indoors vs outdoors), or body weight; there are no allergenfree or hypoallergenic cats. 2,9,[15][16][17][18][19] Fel d 1 production varies widely among individual cats and may vary widely throughout the year in the same cat. 15,16,20 Bastien et al 16 observed an 80-fold difference in salivary Fel d 1 levels between the lowest-producing and highest-producing cats in a 64-cat group and up to a 76-fold difference between the lowest and highest salivary Fel d 1 levels in individual cats.…”