Sex Is The Only Physical Characteristic That Relates To Allergen Production

Sex Is The Only Physical Characteristic That Relates To Allergen Production
Sex Is The Only Physical Characteristic That Relates To Allergen Production

While studies have demonstrated that hair length and color have no influence on Fel d 1 production, there is one physical factor that does appear to correlate: sex of the cat.1-6 

The facts

Sex has been shown in some studies to correlate with Fel d 1 production.


  • It has been shown that intact male cats generally produce higher levels of Fel d 1 than sterilized/neutered male cats and female cats regardless of sterilization status.1, 6-9
  • However, each cat’s level of Fel d 1 varies based on genetics, and an intact male cat could potentially produce less Fel d 1 than a high-producing female or sterilized male cat.1,6,8-11

Find out more

  1. Kelly, S.M., Karsh, J., Marcelo, J., Boeckh, D., Stepner, N., Litt, D.,...Yang, W.H. (2018). Fel d 1 and Fel d4 levels in cat fur, saliva and urine. Journal of Allergy and Clinical Immunology. doi: 10.1016/j.jaci.2018.07.033
  2. Bonnett, B., Messaoudi, K., Jacomet, F., Michaud, E. Fauquert, J.L., Caillaud, D., & Evrard, B. (2018). An update on molecular cat allergens: Fel d 1 and what else? Chapter 1: Fel d 1, the major cat allergen. Allergy, Asthma and Clinical Immunology, 14, 14. doi: 10.1186/s13223-018-0239-8 
  3. Butt, A., Rashid, D. & Lockey, R. (2012). Do hypoallergenic cats and dogs exist?  Annals of Allergy Asthma and Immunology, 108, 74-76.Fel D 1
  4. Nicholas, C., Wegienka, G. & Havstad, S. (2008). Influence of cat characteristics on Fel d 1 levels in homes. Annals of Allergy Asthma and Immunology, 101, 47-50
  5. Siebers, R., Healy, B., Holt, S., Peters, S., Crane, J. & Fitzharris, P. (2001). Fel d 1 levels in domestic living rooms are not related to cat color or hair length. Journal of Allergy and Clinical Immunology, 108, 652-653. doi: 10.1067/mai.2001.118788
  6. Platts-Mills, T.A.E., Vervloet, D., Thomas, W.R., Aalberse, R.C. & Chapman, M.D. (1997). Indoor allergens and asthma: report of the Third International Workshop. Journal of Allergy and Clinical Immunology, 100, S2-S24. doi: 10.1016/S0091-6749(97)70292-6 
  7. Zielonka, T., Charpin, D., Berbis, P., Luciani, P., Cassanova, D. & Vervloet, D. (1994). Effects of castration and testosterone on Fel d 1 production by sebaceous glands of male cats: I. Immunological assessment. Clinical and Experimental Allergy, 24, 1169-1173
  8. Ramadour, M., Birbnaum, J., Magalon, C., Lanteaume, A., Charpin, D. & Vervloet, D. (1998). Cat sex differences in major allergen production (Fel d 1). Journal of Allergy and Clinical Immunology, 10, 282-284.
  9. Jalil-Colome, J., de Andrade, A.D., Birnbaum, J., Casanova, D., Mege, J.-L., Lanteaume, A., Charpin, D., & Vervloet, D. (1996). Sex difference in Fel d 1 allergen production. Journal of Allergy and Clinical Immunology, 98(1), 165-168.
  10. Morgenstern, J.P., Griffith, I.J., Brauer, A.W., Rogers, B.L., Bond, J.F., Chapman, M.D. & Kuo, M.C. (1991). Amino acid sequence of Fel dI, the major allergen of the domestic cat: protein sequence analysis and cDNA cloning. Proceedings of the National Academy of Sciences, 88, 9690-9694.
  11. Bastien, B., Gardner, C. & Satyaraj, E. (2019). Influence of phenotype on salivary Fel d 1 in domestic shorthair cats. Accepted, Journal of Feline Medicine and Surgery.