Any thoughts on this 'Pet Immune Strengthener Supplement'?

Any thoughts on this 'Pet Immune Strengthener Supplement'? for my cat

My cat has been treated for hypothyroidism for 2 years now.




Only Natural Pet Immune Strengthener Immune Support Supplement for Pets

Only Natural Pet Immune Strengthener Immune Support Supplement for Pets
Shop All Products By Only Natural Pet
A blend of vitamins, herbs, antioxidants and mushrooms
Provides immune system support to help your pet fight chronic health issues
Great for both cats & dogs
All natural

Ingredients
Active Ingredients: Reishi Mushroom - 125 mg; Shiitake Mushroom - 125 mg; Maitake Mushroom - 100 mg; Cats Claw - 100 mg; Astragalus Root - 50 mg; Vitamin C (as ascorbic acid) - 50 mg; Vitamin E (as d-alpha tocopheryl acetate) - 35 IU; Vitamin A (acetate) - 1000 IU; Coenzyme Q-10 - 2 mg; Selenium (yeast source) - 20 mcg; N-acetylcysteine - 5 mg; Green Tea Leaf (50% polyphenols) - 50 mg.
Other Ingredients: Chicken Flavor, Liver, Fish Flavor, Rice Flour, Magnesium Stearate, Gelatin Capsule, DiCalcium Phosphate.

http://www.petco.com/product/111188/...-for-Pets.aspx

Discuss it with your vet... I can tell you Mushrooms are great for some but are something likely to cause illness