Wow! Just now seeing this thread.... my 2 cents worth: Heart sounds and grades of LP are pretty much relative depending on each vet. My advice would be to get a second opinion, preferably from a vet that isn't too gun-ho on doing surgery for this condition.
I remember when this surgical repair started becoming popular, prior to that LP was a managed condition, keep the dog from jumping and over-extending. Dogs that continue to jump and overextend themselves even after the surgery can relapse, so behavior modification will be necessary either way. I asked my vet why then do they even offer this surgery? His response was that owners like to do what they can afford to do for their pets, so if they want to do it, we will accomodate them.
Surgery is usually done only when a dog reaches stage 4, or if a dog is showing recurring symptoms or chronic pain.
Glucosamine/chondroitin sulfate products may help. The body makes it own, but as the dog (or person) ages, production slows, which can make symptoms more obvious. Replacing this with a supplement can help in some.
I had Peek A Boo on it for a while, but his tummy was sensitive to it and he would vomit if I gave him a full dose. I cut the dose back to almost 1/4 twice a day, which he could keep down, and I figured some was better than none. I don't recall seeing much improvement, so I stopped it all together about 2 years ago. He can still run faster than me to the kitchen to get a treat, or to sneak a large mouthful of kitty food before I catch up to him.
As you said Cooper has a sensitive tummy, I would recommend starting him out on a lower dose, and work it up gradually to allow his body to adjust to it, over a week or two. (after getting a second opinion)
