Raw, meaty bones are the core ingredient of a fresh, whole-food diet. They are a great source of calcium, phosphorus, and magnesium. The connective tissue surrounding the bones provides cartilage, collagen, glucosamine, and chondroitin, while the meat and fat provide protein and fat-soluble vitamins A, D, and E. Your dog will benefit from chewing as it allows for jaw exercises and mental stimulation and can improve oral health by using all surfaces of her teeth to gnaw on the bone.
Despite the importance of raw meaty bones in a dog’s diet, there are concerns among some dog parents about the safety of bones. There are various reasons, including the dog having few teeth, the fear of choking, broken teeth, bowel impactions, and bacterial contamination. Another reason to need an alternative calcium source is if you choose to cook your dog’s food rather than feed it raw, as cooked bones should never be fed to your dog unless crushed or ground and added to her meal.
Alternative sources of calcium in the form of bone meal, egg shells, or calcium salts can be added to your dog’s diet.
Bioavailability of Calcium
Bioavailable calcium refers to the fraction of calcium present in a food or supplement that is easily absorbed and utilized by the body.Calcium is essential in maintaining strong bones and teeth and supporting proper muscle function, nerve transmission, and blood clotting.
However, not all calcium sources are equally absorbed by the body. Bioavailability measures the extent to which a substance can be absorbed and used by the body. In the case of calcium, bioavailability refers to the proportion of the ingested calcium that is actually absorbed in the gastrointestinal tract and made available for physiological functions.
Factors such as the presence of other dietary components, the chemical form of calcium, and individual differences in absorption efficiency can influence the bioavailability of calcium. For example, calcium from dairy products like milk and yogurt is generally highly bioavailable. In contrast, calcium from some plant-based sources, such as spinach or kale, may have lower bioavailability due to compounds like oxalates that can interfere with absorption.
Bioavailable calcium is the calcium that the body can use, but it does not necessarily imply that it will be fully utilized or retained. Factors like vitamin D status, overall calcium intake, and individual health conditions also influence the body's ability to use calcium effectively.
It is Not Just About Calcium
In dogs, calcium, phosphorus, and vitamin D work in synergy to support skeletal health and mineral homeostasis. It's essential to provide a balanced diet that includes appropriate levels of these nutrients, considering their interdependent relationship, to ensure optimal bone health and overall well-being for your dog. There are three links between calcium, phosphorus, and vitamin D.
Calcium and phosphorus work together for proper bone formation, growth, and maintenance. The ratio of calcium to phosphorus in a dog's diet is essential, and an imbalance between the two can adversely affect bone health. The ideal calcium-phosphorus ratio for dogs is around 1:1 to 2:1.
Vitamin D is critical in calcium absorption and utilization. When dogs are exposed to sunlight or consume foods containing vitamin D, it triggers a series of processes that facilitate calcium absorption from the intestines into the bloodstream. Without sufficient vitamin D, dogs may have difficulties absorbing calcium efficiently, leading to potential calcium deficiencies.
Vitamin D also helps regulate the levels of phosphorus in the body. It promotes the absorption of dietary phosphorus from the intestines and facilitates its transport into the bloodstream. Proper vitamin D levels ensure the appropriate balance between calcium and phosphorus, which is crucial for maintaining healthy bones and teeth.
Whole food sources for calcium, phosphorus, and vitamin D should be fed rather than synthetic supplements if a deficiency in any of the three nutrients is discovered.
Alternatives to Raw Meaty Bones
Ground Bones
The best alternative is to use ground bones, which have the nutritional equivalent of feeding raw meaty bones. Options for ground bones include grinding raw bones at home with an industrial grinder, making bone meal from cooked bones, or purchasing a commercial grind from pet food distributors or raw pet food co-ops.
If you gently cook your dog’s food or make bone broth, you have the essential ingredient for making bone meal: the cooked bones! The benefit of grinding raw bones or making bone meal is that all bone components are present, not just calcium. Ground raw bones will have the best nutrient profile as no heat has been applied.
After you have cooked your dog’s food and removed all the meat from the bones or poured off the broth from making bone broth, boil the bones for several more hours until the bones are soft and malleable. The bone type and structure will determine the duration needed for cooking. Poultry bones require much less cooking time than beef or pork bones.
To determine the amount to use, select oxtail bone as the raw meaty bone on the Feed Real calculator and then multiply that amount by 0.20 to accommodate the loss of water in the bone meal. For example, if your dog needs 2 ounces of oxtail bone, multiply that by 0.20 to get 0.4 ounces or 11.4 grams of homemade bone meal.
When purchasing grinds, determine what components are included. Some grinds contain only muscle meat and bones, while others include liver and other secreting organs.
Calcium Citrate
Calcium citrate is a form of calcium derived from citric acid. It is easily absorbed and utilized by the body due to its high bioavailability. Unlike other calcium supplements, calcium citrate can be absorbed effectively even with low stomach acid, which is common in raw-fed dogs. However, it can be more expensive than other available calcium sources.
Calcium citrate is available in various forms, including a powder, that can be easily mixed into your dog’s food. It typically contains an appropriate ratio of calcium to phosphorus, which is vital for maintaining a proper balance between these minerals in your dog's diet.
There are precautions to take when using calcium citrate. Calcium citrate can interact with certain medications, such as tetracycline antibiotics, and reduce their effectiveness. It's important to consult with your veterinarian to ensure that there are no potential interactions with medications your dog may be taking.
When choosing a calcium citrate supplement for dogs, selecting a high-quality product specifically formulated for dogs is essential. Some dogs may have sensitivities or allergies to certain forms of calcium supplementation, including calcium citrate. Monitoring the dog for adverse reactions is vital when introducing a new supplement.
Differences Between Bone Meal and Calcium Citrate
Calcium citrate and bone meal are both sources of calcium, but they differ in composition and nutritional characteristics. Here are the key points of comparison:
- Composition: Calcium citrate is a calcium salt derived from citric acid. It is an organic compound and is more easily absorbed by the body than other calcium forms. On the other hand, a bone meal is a natural product made from finely ground animal bones. It contains a combination of minerals, including calcium, phosphorus, and trace amounts of other minerals like magnesium and zinc.
- Calcium Content: Both calcium citrate and bone meal are rich sources of calcium. However, the calcium content can vary depending on the specific brand or product. Generally, calcium citrate provides a higher calcium concentration per gram than bone meal.
- Absorption and Bioavailability: Your dog’s body readily absorbs calcium citrate, especially in an acidic environment. On the other hand, a bone meal contains calcium in the form of calcium carbonate, which requires adequate stomach acid for optimal absorption. Additionally, the bioavailability of calcium from bone meal may vary depending on factors such as the quality and processing of the bone meal.
- Other Nutrients: Bone meal contains additional minerals, such as phosphorus and trace minerals, due to its composition derived from animal bones. These additional minerals can contribute to the overall nutritional value of bone meal. On the other hand, calcium citrate does not typically provide additional minerals other than phosphorus in some brands.
Egg Shells
The calcium concentration in eggshells can vary depending on factors such as the laying hen's age, breed, and diet. On average, eggshells are composed of approximately 94% calcium carbonate. The calcium content can range from 32% to 40% of the total weight of the eggshell.
The calcium concentration in eggshells is usually reported as a percentage of the shell's weight. This means that for every 100 grams of eggshell, the calcium content would be approximately 32 to 40 grams.
The calcium in eggshells is primarily in the form of calcium carbonate, which is well-absorbed in the presence of stomach acid with a low pH level. The stomach acid of raw-fed dogs is generally around 1-1.5 pH, which helps break down calcium carbonate into its soluble form, calcium ions. The calcium ions can then be readily absorbed in the small intestine.
As with the other sources of calcium, there are benefits and risks to using eggshells as your dog’s calcium source. Egg shells are a natural and readily available source of calcium, making them a convenient option for supplementation. In addition to calcium, egg shells also contain other minerals like phosphorus and trace amounts of other essential nutrients, providing additional nutritional benefits.
Another benefit is the cost. If you and your family are egg eaters, save those eggshells to feed the dog! You can provide a free calcium supplement, especially if you feed chicken feet as the raw meaty bone in your dog’s meals.
Despite the benefits of eggshells, they have some disadvantages as a calcium source. The calcium content in egg shells may vary depending on factors such as the type of egg, the hen's diet, and the processing method. Ensuring consistent quality and appropriate calcium levels can be challenging.
Egg shells are composed mainly of calcium carbonate, which may have a lower digestibility than other calcium forms. Some dogs may have difficulty breaking down and absorbing calcium carbonate effectively.
Calcium and phosphorus need to be balanced in a dog's diet. Because of the low potassium level in the shells, calcium intake from egg shells can disrupt the calcium-phosphorus ratio, leading to potential health issues.
You should not feed your dog the shells from store-bought eggs. Commercial eggs must be sanitized before distribution. Freshly laid eggs have a protective coating that prevents them from being porous, keeping the water and oxygen in the egg and harmful bacteria out. In the US, as soon as eggs are laid in commercial egg production facilities, they are placed into a machine that chemically washes them, removing that protective layer. The eggs are then susceptible to infiltration of harmful bacteria, requiring refrigeration. The chemicals used to sanitize the eggs can be absorbed by the shell. The level of chemical contamination cannot be determined.
For a more in-depth look at feeding eggs to your dog, see Benefits Of Pasture-Raised Eggs.
Other Whole Foods with Calcium
Whole food sources of calcium for dogs include:
- Fish with bones: The small oily fish recommended in the Real Ancestral 6X Diet™ include bones rich in calcium.
- Green leafy vegetables: Some green leafy vegetables like kale, broccoli, spinach, and collard greens contain moderate amounts of calcium. These can be cooked or blended into homemade meals. However, green leafy vegetables also contain high levels of oxalates, which can be detrimental for dogs prone to calcium oxalate urinary bladder stones .
- Dairy products: Some dairy products like plain yogurt and cottage cheese contain calcium. However, ensuring that your dog tolerates dairy well and has no lactose intolerance or dairy allergies is crucial.
- Cow and Goat Milk: The calcium content in cow and goat milk can vary slightly, but cow milk generally has a marginally higher calcium content than goat milk. Cow milk contains about 120-125 mg of calcium per 100 grams (3.5 ounces). However, the exact calcium content can vary depending on factors like the cow breed, the cows' diet, and the processing methods. Goat milk typically contains slightly less calcium compared to cow milk. Generally, goat milk contains about 110-120 mg of calcium per 100 grams (3.5 ounces). Similarly, the calcium content can vary based on factors such as goat breed and diet.
- Eggs: Whole eggs contain calcium. While the shell provides the highest calcium content, the egg yolk and egg white also contribute small amounts of calcium.
- Bone broth: Homemade bone broth, made from simmering bones and cartilage, can provide calcium and other minerals. It can be used as a supplement or added to homemade meals.
- Tofu: Tofu, a soy-based product, can be a good source of bioavailable calcium, mainly if it has been processed using calcium salts. Calcium-set tofu can provide a significant amount of calcium per serving.
- Nuts and seeds: While not as high in calcium as other sources, nuts and seeds like almonds, sesame seeds, and chia seeds can contribute to your overall calcium intake. They also provide other beneficial nutrients like healthy fats, protein, and fiber.
These whole-food items can be used to enhance your dog’s calcium levels but do not contain enough calcium to be the primary source of calcium. You need a source such as bone meal, ground raw bones, or egg shells to ensure your dog does not develop a calcium deficiency.
Takeaway Bites
- Not all dogs can consume raw, meaty bones. A calcium alternative must be chosen to ensure your dog gets adequate calcium levels.
- Ensuring the source of the calcium alternative is essential.
- The bioavailability of the calcium alternative must be considered when choosing the appropriateness of the supplement.
References
- Effect of Raw Material Source, Processing Systems, and Processing Temperatures on Amino Acid Digestibility of Meat and Bone Meals
- Hen's egg as a source of valuable biologically active substances
- Calcium supplements and structure-activity relationship of peptide-calcium chelates: a review
- Dietary supplementation with flaxseed mucilage alone or in combination with calcium in dogs: effects on apparent digestibility of fat and energy and fecal characteristics | International Journal of Obesity
- The effect of low calcium intake and vitamin D supplements on bone structure in young growing dogs