Did you know that there is a right and wrong balance of calcium to phosphorus in your pet’s diet? A deficiency or excess of either one can have serious consequences for their health. Let’s take a closer look at these two important minerals and how to make sure your furry friend gets the right amount of each.
Table of Contents
What is Calcium?
Calcium is a mineral that is essential for strong bones and teeth. It also plays a role in blood clotting, muscle function, and nerve transmission. A diet lacking in calcium can lead to problems such as bone loss, joint pain, and poor muscle function.
What is Phosphorus?
Phosphorus is another mineral that is essential for strong bones and teeth. It also helps with kidney function and the production of energy in the body. A diet lacking in phosphorus can lead to problems such as bone loss, joint pain, and kidney disease.
How much Calcium and Phosphorus ratio is recommended for dogs?
AAFCO recommends a minimum of 1:1 Ca:P ratio for dogs at all stages. They recommend a maximum Ca:P ratio of 2:1.

Below is a table from peterdobias.com with info on the calcium, phosphorus, and Ca:P ratio recommended for puppies and adult dogs per 1000 Cal.

AAFCO has not provided a recommendation for Ca:P ratio for cats. Cats have different dietary needs than dogs, so it’s best to speak with your veterinarian about the right amount of these minerals for your feline friend.
Why is the Ca:P ratio for dogs important?
Calcification is the process where calcium deposits build up in tissues and organs. This can lead to serious health problems such as kidney stones, heart problems, and even death. A diet with an appropriate Ca:P ratio helps to prevent these problems.
Calcium is also necessary for proper blood clotting. A diet with too much calcium can lead to problems with blood clotting and even death.
According to the Merck Veterinary Manual quoted here, “insufficient calcium or surplus phosphorus can reduce calcium absorption and cause irritability, hyperesthesia (oversensitivity to sensory stimuli), and muscle weakness. Skeletal demineralization can also result from a lack of calcium, particularly in the pelvis and vertebrae.”
Excess calcium can also prevent normal healthy bone mineralization and growth in young (under 1 year old) big and giant breed dogs. Large breeds fed too much calcium are more likely to develop osteochondrosis (abnormal bone growth).
What are the consequences of an imbalance in Ca:P ratio?
Too much calcium in the diet can lead to calcification of tissues and organs, as well as problems with blood clotting. Too little calcium can lead to bone loss and joint pain.
Too much phosphorus in the diet can lead to calcification. Too little phosphorus can lead to bone loss and joint pain.
An imbalance in the Ca:P ratio can also lead to health problems such as kidney stones, heart disease, and even death.
How can I make sure my pet has the right Ca:P ratio in their diet?
The best way to ensure your pet has the right Ca:P ratio in their diet is to feed them a balanced, commercial pet food that meets AAFCO guidelines. You can also speak with your veterinarian about supplements or special diets that may be appropriate for your pet.

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Hi there! My name is Ben Domb, an owner of two pets and I am one of the co-founders of OurPets HQ. I have several years of experience as a pet care professional in the New England region having spent time in various roles including a stint at a veterinary hospital in Upstate New York, Syracuse area. I am a certified pet care professional and mostly spend my time researching pet nutrition and sharing my thoughts in various blogs and columns. With quarantine and COVID restrictions, I have been spending a lot of time a lot with my dogs and cat and loving it! I also run a small consulting business providing advice to parents on pet nutrition, and especially safe homemade options to try. You can reach me at ben@ourpetshq.com