Primarily found in the skeleton. Remaining distributed in extracellular fluids

Functions
Provides structural integrity of the skeleton and maintains proper blood calcium levels  Circulating calcium is crucial for nerve impulse transmission, muscle contraction, blood coagulation, activation of certain enzymes, maintenance of normal cell-membrane permeability and transport, and cardiac function.

Typical blood tests are not a reliable way to determine if enough dietary calcium is being provided because there must be tightly controlled levels in the blood. The body will pull from stores (bones) as needed.

Vitamin D is needed to extract calcium from food.

Signs of Deficiency
Rickets
Osteomalacia
Nutritional Secondary Parathyroidism
Lameness
Spontaneous Fractures

Signs of Excess
Impaired Skeletal Development

Can interfere with absorption of other minerals: Phosphorus, Zinc

Sources
Bone, Supplementation, and dairy

Veggies are not a reliable source of calcium. The amount that one would need to feed to reach daily requirements would create bulk limiting issues.

Supplements, such as calcium carbonate or ground bone, can be mixed in with meat rather than other nutrients which require feeding them fresh.

Recommended ratio cal:p is 1:1 – 2:1

Primarily found in the skeleton. Remaining distributed in extracellular fluids

Functions
Provides structural integrity of the skeleton and maintains proper blood calcium levels through ongoing resorption and deposition. Calcium is always coming and going from the bone for growth and maintenance and as the body’s need for plasma calcium fluctuate. Circulating plasma is strictly controlled through homeostatic mechanisms and is independent of food intake of calcium. Circulating calcium is crucial for nerve impulse transmission, muscle contraction, blood coagulation, activation of certain enzyme systems, maintenance of normal cell-membrane permeability and transport, and cardiac function

Circulating plasma calcium is controlled by homeostatic mechanisms. A constant level is crucial. Mechanisms specifically refer to PTH, calcitonin, and active Vitamin D- calcitriol.

Signs of Deficiency
Rickets
Osteomalacia
Nutritional Secondary Parathyroidism
Lameness
Spontaneous Fractures

Signs of Excess
Impaired Skeletal Development

Can interfere with absorption of other minerals: Phosphorus, Zinc

Sources
Bone, Supplementation, and dairy

Veggies are not a reliable source of calcium. The amount that one would need to feed to reach daily requirements would create bulk limiting issues.

Supplements, such as calcium carbonate or ground bone, can be mixed in with meat rather than other nutrients which require feeding them fresh.

A regular blood test is not an accurate way to determine optimal dietary calcium because of the homeostatic mechanisms.

Recommended ratio cal:p is 1:1 – 2:1

Primarily found in the skeleton and the remainder is distributed in soft tissues. 

Functions
Also lends structural support to the skeleton and is also released into the bloodstream. Involved in almost all of the body’s metabolic processes. Phosphorus is needed in energy metabolism.

Signs of Deficiency
Depraved appetite, pica, decreased growth, decreased fertility, dull coat, spontaneous fractures, rickets.

Signs of Excess
Hypercalcemia, bone resorption, soft tissue calcification

Can interfere with calcium and magnesium absorption.

Sources
Bone, bone meals, meat, poultry, fish

Phosphorus from plant sources can be absorbed at a fraction (1/3) of animal sourced phosphorus.

Primarily found in the skeleton and the remainder is distributed in soft tissues. 

Functions
Also lends structural support to the skeleton and is also released into the bloodstream similar to calcium. Involved in almost all of the body’s metabolic processes. A constituent of cellular DNA and RNA, some B-vitamin coenzymes, and the cell membranes phospholipids. This is crucial for regulating the transport of molecules across cellular membranes (so many many many processes in the body in general).

Phosphorus is needed for cell respiration.

Signs of Deficiency
Depraved appetite, pica, decreased growth, decreased fertility, dull coat, spontaneous fractures, rickets.

Signs of Excess
Hypercalcemia, bone resorption, soft tissue calcification

Can interfere with calcium and magnesium absorption.

Sources
Bone, bone meals, meat, poultry, fish

Phosphorus from plant sources can be absorbed at a fraction (1/3) of animal sourced phosphorus.

Found in all body cells, mainly hemoglobin and myoglobin. Stored Primarily in the liver, spleen, and marrow. Also functions as a cofactor for several other enzymes.

Functions
Present in all body cells, iron present in Hemoglobin aids in transport of oxygen from the lungs to the tissues while myoglobin binds oxygen for the immediate use by muscle cells

Iron is a cofactor for several other enzymes and a component of the cytochrome enzymes.

Signs of Deficiency
Increased clotting time, hemorrhage. This would be very rare and would normally occure because of chronic blood loss

Signs of Excess
There are few studies of toxic intake of iron for both dogs and cats and when symptoms manifest for toxicity, it was due to experiments with fasting dogs and/or supplementation. There is no SUL for iron in dogs or cats because the experiments are not applicable to dogs eating standard diets. There is not enough data for cats. Iron should never be supplemented carelessly.

High dietary intake of iron can affect hepatic copper stores. (In studies where the ratio of iron to copper exceeded 20:1).  Very high levels of iron should also be avoided because of interference with minerals such as zinc and copper. The body has limited ability to excrete iron and therefore homeostasis is maintained by adjusting iron absorption.

Overall, iron absorption is affected by
1. Iron status of the body
2. Availability of dietary iron (as affected by other ingredients and nutrients)
3. Amount of heme and nonheme iron.

Sources & Nutrient Interactions

Organ meats (liver, kidney), egg yolk and fish are high in iron.

Heme iron from animal sources is much better absorbed than non-heme sources (plants). During formulation, one should take care to recognize the source where iron is coming from.

An acidic intestinal environment generally improves iron absorption.

When the body has low stores of iron and increased metabolic needs there is increased absorption efficiency.

Phytate, phsphate, and exceess oxalates can negatively affect absorption. Excess zinc and calcium can also negatively affect absorption.

Mainly found in the blood. Found in liver and excess excreted in bile.

Functions
Copper is needed for normal absorption and transport of dietary iron. Oxidation of iron is required for binding to transferrin. Copper is needed for the conversion of amino acid tyrosine to the pigment melanin, for the synthesis of collagen and elastin, and for the production of ATP. Copper is a vital constituent of many enzymes. Copper also plays a role in elimination of free radicals, bone development, and pigment development. Copper is also needed for the formation of myelin sheath. Copper also plays a roll in the breakdown of histamine.

Signs of Deficiency
Hypochromatic microcytic anemia
Impaired skeletal growth young animals
Depigmentation of colored hair coat.

Signs of Excess
Inherited disorder of copper metabolism causes liver disease in some breeds of dogs:

Cocker Spaniels, Dalmatians, German Shepherds, Keeshonds, Kerry Blue Terriers, Labs, Old English Sheepdogs, Poodles, Samoyeds

Sources
Most ruminant liver sources. Poultry liver will have bioavailable copper, but the amount is often not high enough to be the only copper source in the formulation. The Copper found in pork liver may not be bioavailable and shouldn’t be relied on. Eastern oysters are rich in both Copper and Zinc.

Main cation in intracellular fluid. ⅓ of cell’s potassium is bound to protein. The rest is in ionized form.

Ionized potassium  provide osmotic force that maintains proper fluid volume.

Also responsible for numerous enzymatic reactions.

The small amount in the extracellular fluid aids in transmissions of nerve impulses and muscle contraction. Therefore, is important for the normal functioning of the heart muscle.

It helps regulate the acid-base balance of the body.

Converts glucose to glycogen in the liver and needed for normal growth.

Sources
Meats, poultry, fish, sweet potato, banana. and fresh plant materials in general.

Ionized sodium is the major cation found in extracellular fluid. Provides osmotic force that maintains aqueous environment in the extracellular fluid. Functions to maintain normal contractility of muscle fibers.

Sodium controls the electrolyte balance between intracellular and extracellular fluid compartments. Sodium chloride is a chief source of sodium.

Dogs and cats seem to be physiologically capable of adapting to wide ranges of sodium intake. Sodium should be watched in pets with some health conditions.

Located outside the cells in the surrounding fluid. It is also inside the cells and in bones. Fluid and acid base balance of the body.

Chloride ions make up for about ⅔ of total anions present in extracellular fluid. Regulate osmotic pressure, water balance, and acid-base balance. Important for the production of gastric enzymes.

Dietary needs parallel sodium intake. Chloride is not in nutrient analysis.

Sources
It is uncommon for proactive diets to be too low in sodium and chloride. However, salt can be easily added to the diet in such instances.

Manganese functions as a component in cell enzymes. Manganese can be found in the mitochondria of cells. Manganese helps regulate nutrient metabolism. Manganese is also especially important for growing animals in regards to bone development and reproduction.

In other species, manganese deficiency has caused decreased growth, impaired reproduction, and disturbances in lipid metabolism.

Manganese is needed for cartilage and is critical for joint health.

Sources
Manganese is rich in raw green tripe (not the washed kind from the grocery stores) and BLUE mussels. The level in tripe can vary significantly. Digestible carbohydrates typically provide appreciable amounts of Manganese. Some dogs will do better with higher levels relative to proactive levels when it comes to joint health.

Iodine is needed for the synthesis of hormones thyroxine and triiodothyronine by the thyroid gland.

Too much or too little can have serious effects. Meat has varying levels of iodine that do not show up in food databases. Iodine rich sources typically needed to be added to a fresh food diet. Kelp is most often used. However, make sure the Kelp product tells you how much iodine is in their product.

Naturally occurring iodine deficiency does not occur commonly in dogs or cats, though principal sign of deficiency is goiter. Failure to grow, skin lesions, and CNS dysfunction can occur in growing animals fed a deficient diet.

Sources
Kelp, fish, eggs, supplements