Influence of time and phenotype on salivary Fel d 1 in domestic shorthair cats

Fel d 1 is a major cat allergen, accounting for up to 95% of human sensitization to cats. The allergen is produced primarily in the cat’s salivary and sebaceous glands, is distributed throughout the cat’s hair during grooming, and enters the environment on the cat’s dander (shed flakes of skin) and hair. This study analyzed saliva samples from domestic shorthair cats (a common breed) before and after feeding, every other day, for one year. Salivary Fel d 1 levels varied significantly between cats and within the same cat over the course of the year. There was a greater than 80-fold difference between the lowest and highest average Fel d 1 levels between cats. The study showed that salivary Fel d 1 production is variable among cats, and there are naturally occurring low Fel d 1 producer cats among populations of domestic shorthair cats. Although older cats tend to produce lower levels of salivary Fel d 1, the allergen’s production was not affected by sex, coat color or pattern, or body size.