I have had cat allergies all my life which is a REAL bummer because I'm an animal lover and love kitties! My main symptoms? Itchy eyes. I get one cat hair near me and my eyes turn red, swell, start watering and then itch horribly. This is a common allergic reaction to cats. If it is a new cough, I'd say it's likely a virus and coughs linger with that. Once the air way is irritated, the cough will stay for a bit. But all allergies I suffer and my son involve itchiness. Itchy nasal cavity, itchy sinus or itchy eyes. I'm guessing your cats are not the problem.
I doubt very much that your son has developed an allergy
to your cats especially since you said that you have had your
cats for several years. My advice would be to make an appointment
with your son's regular doctor and see what advice he or she offers.
Coughs can also be caused by dry air in your home. You might consider buying a humidifier for your son and placing it in his bedroom. Dry coughs can also be caused by asthma. Hope these suggestions are helpful.
Try alternative medicine NAET with a chiropractor.
There is a DETOX for allergies. Once you have completed the Detox the doctor can help using NAET on specific issues.
I have used NAET for 10 years. Once I completed the DETOX protocol. I used for other issues such as; rashes. Viruses. Bacteria, lung and cough, blood sugar, inflammation etc.
My health is better.