where is this product manufactured from

Our products are manufactured right here in the US. :)

how long does the container last?

It's hard plastic. The container will last forever.

Anyone switched to these from synovi g4 lately? any difference in your pet? (yes, it would be very nice, to see if ingredients imported from china!)

I spoke to one of their customer service reps she told me the company changed ownership about a year ago and since then they do occasionally purchase ingredients from China

I notice the description states it contains probiotics, glucosamine, and fish oil. does it actually contain enough of these to actually be helpful?

I use these and the Cosequin chews, and 50mg of CBD daily. Bailey gets one cosequin a day - after being "loaded" the first few weeks you do not have to give more than one. Bailey has been on a diet to lose weight to help with he hips, she has severe arthritis of both hips so she needed to go from 94lbs to 75, she is at abt 80 now - because of the decrease in calories her skin and coat suffered, within a few days I saw a great change in her coat, her coat was coming back and the dry skin started flaking away, now two months later her chocolate coat is gorgeous again and she is acting like a puppy (the CBD is responsible for a lot of that but the vitamins are a huge boost) I am going to cut back to one multivitamin a day and hopefully she'll do well, if not I will increase it.