As dogs reach their senior years joint mobility may worsen, therefore movement like walking can be more painful and difficult. Vitapet Double Strength R~A Joint Formula contains a unique belnd of pure refined fish oils, naturally high in Omega-3 nutrients EPA (Eicosapentaenoic acid) and DHA (Docosahexaenoic acid). Research has indicated that increased levels of these nutrients may help to maintain pain-free joints. The blend also contains vitamin E, an important in vivo antioxidant. Double Strength R~A Joint Formula contains a natural high level of 25% Omega-3, double the strength of Normal R~A Joint Formula. Higher Omega-3 levels mean better for helping older dogs as well as larger breeds in helping maintain their mobility, circulation and a healthy heart. Suitable for puppies over 12 weeks. Introduce into your dogs diet gradually.