Eggshell Powder Is A Great Source of Calcium For Cats

Cats fed a homemade diet can get a lot of excess phosphorous without getting much calcium, because homemade diets usually lack crushed bone. Without the crushed bone, your cat can become deficient, which can lead to health problems down the road. Calcium deficiency in cats can be serious, creating problems with dental health and even deformation of the face. Luckily, there’s an easy fix for this problem: eggshells.

Providing Calcium…and So Much More

Crushed eggshells do wonders for cats in need of dietary supplements. One fully crushed eggshell can provide up to 800 milligrams of calcium*, which is enough for two meals. In addition, crushed eggshells contain vital elements like:

  • Boron
  • Magnesium
  • Manganese
  • Zinc
  • Copper
  • Iron
  • Sulfur
  • Molybdenum
  • Silicon

There can be as many as 27 of these elements in a single eggshell, providing nearly as much nutrition as crushed animal bones.


To prepare your crushed eggshells, start by cleaning the shells gently with warm water and a clean dish rag. Next, crack open the shells and deposit the egg yolk and egg white into a container away from the shells. Next, rinse the eggshells under a gentle stream of water. Be sure to leave the membrane on the inside of the shell, as this is a good source of nutrition for your cat.

Allow the shells to dry completely. If you’re not sure how to tell when they’re dry, place them on a paper towel overnight and leave them out in the open.

Bake the shells at 300 degrees to make them more brittle and easily breakable. This will help you grind the shells up into as fine a powder as possible.

When they’re fully dry, use a coffee grinder to grind the shells. Remember to fully clean out the coffee grinder to remove any traces of coffee. If the grinder has multiple settings, set it to the finest grind possible.

If you don’t have a grinder, grind them up under a rolling pin. Place the eggshells in a baggie or between two paper towels to help keep the shells contained.

When you’re finished grinding the shells, sift them with a sifter to remove the biggest pieces.


Store the eggshells in a cool dark place, contained in a glass jar with a lid. Don’t leave the eggshell powder out where it can be exposed to moisture.

Adding Eggshell Powder to Food

When it comes time to add the eggshell powder to your pet’s diet, weigh the meat to determine how much eggshell powder should be added to it. Plan to add 1 teaspoon of eggshell powder to every pound of meat. 1 pound of meat = 1 teaspoon of powder, and so on. If feeding your cat less than a pound of meat, make the the fraction of eggshell proportional to the fraction of meat your pet will consume. (i.e., 1/4 pound of meat = 1/4 teaspoon of eggshell)

At the National Animal Supplement Council, we believe it’s important for your pet to get the calcium he or she needs to survive and thrive. Join our membership today and support our mission to ensure a healthy natural diet for pets.

*The NASC does not endorse all of the products on external websites. Please always check for the NASC Quality Seal!