Rickets is a Vitamin D deficiency, but lack of calcium too. The cheapest way to help with the calcium is to give the puppies 1 or 2 tums pills a day (which is straight calcium but most of the time they will eat it kind of as a treat, just easier). Also keep them in the sun just like the other man said. You also need to make sure they are eating well sometimes something else might be wrong too making it seem like ricketts. We most of the time just pour milk over their food helps most of the time to keep up their appetite. Hope this helps. Good luck!