When balancing the macro-mineral portion of a petfood, calcium and phosphorus are usually the first priority, magnesium seldom requires adjustment, and sodium and chloride, if inadequate, are easily met with a pinch of salt (sodium chloride). All that remains is potassium.
Despite the fact that most of the dietary ingredients used in petfood, such as protein meals and grains, contain some potassium, they seldom deliver an amount sufficient to meet all the animal’s needs. One might argue that vegetable and fruit matter are rich in potassium and thus a source adequate to the task of filling this gap. However, these ingredients are usually not a significant enough part of a commercial petfood to make up the difference.
