Ensuring calcium is enough in homemade diets

The natural composition of many foods we use for our dogs, especially meat and organs, tend to be richer in phosphorus than calcium.

See this chart which gives a glimpse of calcium and phosphorus levels per 100 grams of 6 foods:

The European Pet Food Industry Federation (FEDIAF) provides nutritional guidelines for pet food and they recommend a minimum calcium to phosphorus ratio of 1:1 and a maximum ratio of 2:1.

Given that many ingredients have much higher phosphorus levels compared to calcium, homemade recipes can easily become unbalanced if attention is not paid to calcium.

In order to get the calcium to phosphorus ratio 1:1 in meals, ingredients that are very high calcium levels are needed. These would be egg shells, a calcium only supplement, raw chicken wings and raw bones (smaller non-weight bearing ones).

When our family started paying attention to calcium, our go to was adding ground egg-shells. We were never sure how much to add as I hadn't gone back to school to study canine nutrition yet, so we were winging it.

Excessive calcium in diets is a concern when it exceeds 2:1 ratio to phosphorus. Too much calcium blocks the absorption of iron, zinc and magnesium. 

To take the guesswork out of balancing your dog's homemade meals, here's a simple guide on how much calcium (using ground eggshells) to add to get your homemade meals to a 1:1 calcium to phosphorus ratio. 

• 1 teaspoon of eggshells weighs about 5 grams
• eggshells from one egg weight about 7-8 grams

Note: For recipes with significant amounts of bone-in meat  (whole chicken wings or sardines with bone-in) or other calcium-rich ingredients, you may need less.