One would not use all of the homeopathics together. With homeopathy one matches symptoms to the patient. For your older dog with arthritis I would use Arthro-Ionx. If he has occasional severe days then I would give Promaxol. It is handy to have Promaxol in the house in case there is some event that happens that produces pain, you can give it immediately to help remedy the situation.
For the puppy I would use Derma-InX for the itchy skin. When that is under control then you might want to consider H20-IonX for maintenance. In addition I recommend digestive enzymes, probiotics, MSM, and vitamin C. Your German Shepherd might also benefit from some extra fish oil. Sometimes I also use glucosamine for large breed growing dogs or arthritic ones.
We do have offer a daily vitamin called Omega 3/6/9. It provides balanced ratio of Omega 3, 6, and 9 oils from non-GMO fish, flaxseed, and borage seed. Our Omega vitamin helps support maintenance of healthy skin, heart, joint, and immune system and comes in a convenient softgel capsule that is mess-free and easy to administer.
When you order you might want to also order some Defendex shampoo too. It is nontoxic and does a good job. I use it on my pets for regular baths. In case they pick up any fleas it makes it easier to spot them.
Please let us know if you have any other questions.