I've always kept Jasper at around 35kg, adjusting his diet if he got above 36kg or under 34kg. I weighed him today for the first time in going on 2 years, and he's 33.8 kg, so he's dropped a bit and I'm wondering if I should feed him up. However, I know he's lost a lot of muscle mass in his hindquarters, and I don't want to just replace that with fat. I'm also well aware that being a little under- rather than overweight will be better for his joints, and he really is lacking strength in that back end. Here's some photos, though I know they're not a good substitute for seeing the dog in the flesh.