So sorry to hear that. I'm definitely not an x-ray person. His hips (to me) don't look TOO bad. But not sure I could tell the difference between moderate dsyplasia and mild hips. Excellent hips and really bad hips stand out! Elsa has mild HD in one hip and honestly we haven't made any adjustments to lifestyle and she's had NO problems. Maintain with supplements and that's it. Maybe it will catch up to her when she gets older, but for now we are going with it.
You've probably seen this website, but just in case
Degenerative lumbosacral stenosis in dogs - Veterinary Medicine
So sorry to hear this. Hope it ends up being nothing. The surgery to alleviate the lumbar issue sounds very successful, so at least that's promising :-/ And it sounds like in some dogs 4-6 weeks of medical treatment is all tha is needed?