
So sorry to hear this - you need to check the content of the KD food, my GSD had kidney failure and vet put her on tinned KD but the protein level was very low. Now it's not a low protein your dog needs its low phosphorous. You can look up what's in all the dog foods and look for phosphorus. I had an added complication in that my dog was allergic to rice which is great for kidney problems. A lot of fatty food is good - breast of lamb and chicken legs (cooked and feed the skin) butter is good too. You should additionally feed calcium (not tablet form as it includes vit D) in the form of crushed eggshells or 'tums' for stomach upset. Tums are calcium and very useful too. Feed with one meal. With the other meal feed whole fish oil (not cod liver ever for kidney problems) vit C and E.
Calcium inhibits the absorption of vitamins and phosphorus so feed with one meal. Don't feed vit D as this stops the calcium from inhibiting absorption (which is why it's included in vitamin supplements but you WANT it to inhibit absorption). Check phosphorus levels of everything you feed - needs to be as low as possible. I know I ended up feeding I think Royal Canin puppy food as it was low phosphorus and no rice, but if you're not avoiding rice it's a lot easier.
Dogs fed on a low protein diet will not live very long - your dog needs protein and fats, but not phosphorus.
Good luck
Penny