No problem! Yes adding those separately is a great idea. It really is quite overwhelming as there are hundreds of brands out there, some offer senior foods, some do not. Currently, there are no requirements that a food has to meet in order to be labeled a senior food. You will see all senior formulas will say something along the lines of “formulated to meet all the nutritional levels established by the AAFCO for adult maintenance”. That is the exact same thing an adult food will say. It may say for All Life Stages in place of Maintenance which means it also meets the minimum requirements for puppies.
There are established requirements for puppies and adults but not seniors so feel free to use an adult food or all life stages food. What I typically look for for my older dog is 25-30% protein, 10-16% fat, 3-6% fiber, phosphorus preferably no higher than 1.5%, sodium around 0.3% no higher than 0.4%. These are just some levels I find works for my older dog and the levels I have talked over with my vet. These protein, fat and fiber levels are just what works personally for my dog, yours may need higher or lower.
The reason I do not like to see high phosphorus for an older dog is because it can be hard on the kidneys and it is not exactly rare for older dog’s kidney health to decline. I stick to foods that do not have too high of sodium to keep the heart healthy as heart health also often declines with age. My dog now has a murmur so I am careful about that.
And I am rambling lol hopefully that little guideline will help you find something suitable for your dog that is reasonably priced. I find having an idea in mind on what to look for in a food can help narrow down all the options
