Here at CatFoodDB we use an algorithmic formula in order to individually analyze thousands of unique cat food products sold under almost 200 different brand names. We do this using data provided straight from the manufacturer - the product ingredient lists and its published guaranteed analysis. In most cases, our information is obtained directly from the product's website, but occasionally when the data is not published online we will use photos of the individual products or obtain the data from reliable retailers such as chewy.com.
Using this data, we generate two separate scores for each product.
The first score is the product's ingredient score, where we rate the product's ingredient list on a scale of 1-5 paws (ie from to )
The FDA requires that ingredients in pet food are listed in descending order of predominance by weight, which means the heaviest ingredients are listed first. With this in mind, our algorithm prioritized cat foods containing high quality protein sources such as chicken, turkey, beef, rabbit, duck, lamb, venison, etc in these first few positions. Additionally, foods that do not contain cheap fillers (corn, rice, wheat, etc), questionable additives (carrageenan, guar gum) or controversial preservatives (such as BHT, BGT, etc) will score the best. Seafood-based products will score slightly less than an equivalent land-based protein-based product.
The second score generated, also on a scale of 1-5 paws, is based on the product's published guaranteed analysis. The Guaranteed Analysis is how pet food companies in the USA and Canada report on the nutrient content of each product, and is roughly equivalent of the Nutrition Facts panel that is printed all human food product packaging. The guaranteed analysis is expressed in terms of percent maximums and minimums, and represents the cat food "as fed". "As fed" means as the food comes out of the bag or can. Unfortunately, these numbers are often quite misleading as we need to normalize the moisture content in foods before they can be reliably compared. Doing so is known as calculating the "Dry Matter Basis" - more information on why and how can be found here. No worries though, here at CatFoodDB we do this math for you for each and every product reviewed, and we also use the Dry Matter Basis to calculate our reviews. Higher protein, lower carb products will score the best here.
When discussing an individual product, we will publish both score for each product. When calculating overall brand ratings, we calculate the average of each of the brand's individually reviewed products.