Is your dog or cat getting the right amount of calcium?

Homemade diets are popular with a lot of pet owners. But when you’re developing your dog or cat’s menu, you need to ensure he’s getting all the nutrients he needs, and in the right amounts. One of those important nutrients is calcium. Your pet’s body cannot, on its own, maintain the appropriate levels of calcium to phosphorus (more on this important ratio later) so it’s crucial to understand why calcium must be added to home-prepared diets – and how it should be added.

“Calcium is a very important mineral and is a major component of bone and cartilage,” says pet nutrition counsellor Heather Macfarlane. “Proper calcium intake ensures healthy bones and teeth. Calcium also plays a role in hormone transmission, nerve function, muscle contraction, digestion, cognitive function, and blood clotting.”

“Calcium is the most vital nutrient we need to worry about with a fresh food diet,” adds holistic veterinarian Dr. Keith Weingardt.  “If your dog or cat ends up with low amounts of calcium, he will resorb calcium from storage areas in his body, which results in a whole other set of serious problems.”

The key ratio – calcium to phosphorous

“It’s challenging to say ‘this size dog needs this much calcium’,” says Dr. Weingardt. “The food your dog or cat is consuming should achieve an optimum calcium-to-phosphorous ratio. It’s the quantity of food, along with the quantity of phosphorous-containing foods, that determine the amount of calcium to be supplemented.”

What many people don’t realize is that the meat and poultry we give our pets has high levels of phosphorus. So in many cases, calcium must be added in order to achieve the appropriate – and ideal – ratio.

How should you supplement calcium?

Note that the following points are guidelines. As always, before switching your pet’s diet and/or supplementing him with calcium (or any other nutrient), consult with a holistic or integrative vet about your own dog or cat’s individual needs. These needs can vary depending on his age, size, health issues, etc.

  1. Heather suggests that if your dog is being fed a home-prepared raw diet, bone-sourced calcium can be used as a supplement. Typically, 5% to 8% of a raw diet should be made up of bone in order to provide an adequate amount.

First, you must ask two key questions: what type of animal protein is being fed in the diet, and can that animal’s bones be easily ground up? If the answer to the second question is yes, try using the raw bones of the animal you are feeding your pet; for example, whole/ground rabbit or chicken bones are easy to grind. If you are feeding venison or beef to your pet, and you have a meat grinder, consider grinding down the rib bones. Remember to only give him raw (not cooked!) bone, and to vary protein sources so your pet isn’t eating the same meat all the time.

  1. You can also add eggshell powder to ground bone; eggshells are a food-based source of calcium carbonate and don’t have any phosphorus.  (See sidebar for instructions on how to make eggshell powder.)
  2. If you prepare homemade meals for your pet that don’t contain bone, you should supplement with calcium. Dr. Weingardt recommends Calcium Citrate Pure Powder from NOW Foods. His rule of thumb is 1,000 to 1,200 mg per pound of home-prepared food.
  3. Do not use yogurt as a supplement for your dog or cat. Although yogurt is good for your pet, and provides him with natural probiotics, it shouldn’t be used as a primary source of calcium.

Don’t over-supplement

Too much calcium can be as problematic as not enough – another reason why you need to work with a veterinarian when determining the right amount for your own pet. In dogs, it can result in different types of bone deformities, and joints can break down, especially in large breed puppies. Excess calcium in cats can lead to poor growth, increased bone mineral density, and a greater need for magnesium.

If you feed your dog or cat a high quality frozen raw or premium packaged food, then you probably don’t need to worry about adding extra calcium to his diet. In fact, too much can also cause problems (see above). But if you’re opting to home-prepare your best friend’s food, you need to make sure your he’s getting enough of this important mineral.

How to make eggshell powder

Preparing egg shells is easy. “It requires only a couple of teaspoons of eggshell powder to balance out the phosphorus in most diets,” according to Rick Woodford, also known as “The Dog Food Dude”. His book Feeding Your Best Friend Better, has a recipe for eggshell powder: “it will make about 12 teaspoons, each with about 1,800 mg of calcium.”

Eggshell Powder


12 eggshells, cleaned and dried


Once clean and dry, eggshells can be left at room temperature in an airtight container until you save enough to make a batch.

Preheat over to 300°F.

Spread the eggshells evenly on a baking sheet and bake for 5 to 7 minutes. The eggshells will still be mostly white or brown, but might have a light tint, which is okay. Baking eggshells longer can product an unpleasant smell.

Allow the eggshells to cool, then grind in a blender or clean coffee grinder for 1 minute, or until you achieve a very fine powder with no sharp edges.

Store at room temperature in an airtight container for up to 2 months.

Calcium supplements

superCal or MegaCal, Young Living,

Calcium Citrate Pure Powder, NOW Foods,


Christine Caplan is a Certified Vet Tech, and a long-time PR veteran and content marketing expert who brings her unique understanding of social and digital media to connect dog lovers to brands both on and offline. She lives with three hounds – two “doxies” and a beagle/basset hound mix – who constantly teach her about life and companionship (