Original Question: My cat’s Orion and Sebastian are both overweight. I'm considering a weight loss type of formula, prescription or OTC, preferably grain free. My vet told me years ago that higher protein diets contribute to the development of kidney disease or other renal issues (specifically kidney stones.) Most of the dry foods have much higher protein levels than in the past. I'm just wondering where the vet community is on this issue and what amount of protein would be good for adult cats under 5 years old. - Kate
Thanks for your question.
I’ve answered your question in two parts so I’ll answer them separately.
What are some tips on how to get my cat to lose weight?
Here’s what I suggest. Speak to your veterinarian and get a nutritional consultation. Sometimes the registered veterinary technicians will offer free weight management consultations. The medical food companies and some independent advice-providing companies offer a software program for determining the ideal caloric intake for our pets. They are based on Body Condition Scoring. You do not base caloric intake decisions on age or simply weight. Your veterinarian, or possibly the registered veterinary technicians, will tell you your cat’s body condition score simply through a physical exam. Then they enter that information, along with weight and age, into the program and it will calculate the ideal daily calorie intake for cats that is necessary to achieve a healthy body weight. By inputting the caloric density of the food you have, or one that is recommended, it will determine the amount of food to offer. You’ll want to measure, or better yet, weigh the food out to be certain that you are offering the right amount. You can visit your veterinarian for a weigh-in on a regular basis and make sure that you are on track.
If you don’t want to visit your veterinarian to go through this, you could call one of the medical food companies and they will likely guide you through this. The challenge would be determining an accurate body condition score without them seeing your cats, but they do offer very good resources to determine this yourself.
How much protein does a cat need?
As far as your concern goes regarding the content of protein in cat food and whether it contributes to kidney disease, it doesn’t have a confirmed answer. It’s true that when cats develop kidney disease, they are put onto a reduced protein diet that has high quality, easily digestible protein for cats. It’s the nitrogenous compounds that come from digesting the protein in the diet that contribute to the toxins that build up in the bloodstream of cats with reduced kidney function. However, if your cat’s kidneys are functioning normally, there shouldn’t be a concern. In some cases, kidney disease can be occurring at a very early stage wherein it is not yet causing clinical symptoms and in those cases a reduced protein diet would certainly help. So given the options, I would lean towards something with a lower protein content in general for cats especially as they age.
I hope this helps.
Dr. Clayton Greenway