How much chondroitin, glucosamine and msm is in each dose?

1500 mg of glucosamine, 120 mg of chondroitin, and I'm not sure about the msm. The msm is listed with other ingredients which all equal 1600 mg

Is the product sealed?

Yes, there is a protective "Lift and Peel" seal underneath the cap.

what is the cost per day for 90# dog buying 2 months at a time?

Each one 8oz bottle of Flexicose will last 2 months/64 doses for a 90# dog (up to 100#) per manufacturer recommendations- so two bottles will last 4 months dose. Depending on your cost paid per bottle, shipping, etc., the daily cost per day will vary. Hope this is helpful!

Does this contain any potato based ingredient? My girl is allergic to any potato ingredient.

Hello! Flexicose is gluten-free and contains no starch, dairy, or table salt. While we are not aware specifically re: potato, Flexicose is made in the USA at a certified organic Certified Good Manufacturing Practices (cGMP) facility and has an excellent reputation for nearly 20 years. We may also recommend the Pet Flexicose PLUS for even greater benefits, our best seller. Hope that this helps!