Just wondering if you've tried Petalcleanse? Its a lotion you just wipe over the cats' coat once a week and it reduces the level of allergens. It does take a few weeks for the allergen levels to reduce so its worth perservering with for at least 3 weeks if poss to see if it is going to help your son at all. Pet Allergy? Petal Cleanse can help with the symptoms such as Asthma, Eczema, Hives and Sneezing I've used it for years on my cats and its really helped me with my allergies. I just thought it would be worth a try if it could mean that you'd be able to keep Tigger.