Which Purina, Royal Canin, or Hill's cat food has lowest phosphorus for aging kidneys?

Great question! One of the benefits of Royal Canin aging 12+ is that helps support renal health by having reduced phosphorus. It doesn't say if it's lower in sodium, but it is an excellent food for older cats and has the reduced phosphorus which is important given the prevalence of kidney disease in older cats. I recommend it as a food option for Tony. I hope this helps!

I don't have a completely simple answer for you, but I can give you a chart for comparing phosporus levels in different foods. http://catinfo.org/docs/CatFoodProteinFatCarbPhosphorusChart.pdf For maintenance diets, AAFCO minimum for phosphorus is 1.25 g/1000 Kcal (1.25% on a dry matter basis) so, if you are looking for non-prescription diets, there will be none lower than that, so you can try to look for diets that are closer to that value. I hope that was helpful! Thanks for using PetCoach.

Royal Canin carries a diet called Senior Consult which has restricted Phos but not as low as the renal diets so it is not appropriate to feed instead of the renal diets. I recommend to discuss this option with your vet before making any diet changes since they are the most familiar with Tony's history. You may ask your vet about an appetite stimulant such as mirtazapine. Many renal cats want variety. Many owners will keep several renal food options and will switch the kibble every week to keep it interesting. Most cats will go back to eating a diet that they had previously stopped eating so you may try circling back. You should also ask about the return policy when purchasing the food in case Tony won't eat the food. I hope this helps and please feel free to post any additional questions.

Hello, & thank you using Petco Pet Education Center, formerly Petcoach. The most important thing for you to consider is the palatability of food for Tony. The best food for the kidneys will do him no good if he will not eat it. That being said, I think the Sci. Diet Adult 7+ is an excellent choice. The phosphorous level is actually a bit lower or about the same than in some of the Royal Canin renal diets. He should do quite well on this. Take care.

The key here is to go VERY slow. I saw a presentation by Hill’s that said over 90% of cars will eventually transition into a kidney diet- but it can take up to two months. I’d say go back to whatever Tony was eating well and try one of the following: 1) If he eats dry food, mix in a few kibbles of the kidney food at each meal. As he begins to finish all the food, very slowly creep up on the prescription food and back off on the regular food. 2) If he eats dry food but is interested in wet - or eats a mix of wet and dry: top dry food with a tiny dollop of canned kidney food. As he begins to eat this, replace more and more kibbles with wet kidney food. OR, if you want to keep him on a mix of both, start slowly replacing the kibbles as described in option 1. 3) If he eats only canned, mix a tiny bit of canned kidney diet in with it. Same as for the dry food, slowly increase the kidney diet and decrease the regular stuff. Again, this could take a month or two so be slow and patient. Best wishes to you and Tony.

Because this food isn't prescription, it won't be formulated to be lower in phosphorus and protein. I would speak to Tony's vet to see if they recommend using something as a topper to get him to eat his food.

Senior diets tend to increase protein as animals lose muscle mass as they age. You would do best to stick to diets formulated for kidney disease as they will take other factors into account such as phosphorus etc.