Together with calcium, it is found practically throughout the body, but most phosphorus is accumulated in bones and teeth (structural role). It plays an absolutely key role in the body - it is energy fuel for every cell (functional role). It is responsible for accumulating and storing energy in the body (a component of high-energy bonds found in ATP), builds DNA molecules and takes care of the acid-base balance of the blood [1]. Phosphorus is always considered together with calcium - more in the article calcium:phosphorus ratio and Calcium. Bone metabolism and the absorption and retention of phosphorus depend on vitamin D and the amount of these and other minerals in the diet. Phosphorus is an essential nutrient for dogs and cats that must be supplied with [2] food. When using the BARF diet, it is very important to control its level along with the calcium level to avoid bone structure disorders.
What it contains: Muscle meat, fish (salmon, trout, sardines), offal (liver, heart), egg yolks. Supplementation is most often in the form of purified salts, mainly calcium phosphate.
Deficiency: It is virtually non-existent in a meat-based diet, unless we block its absorption with a drastic excess of calcium [1]. It leads to apathy, stunted growth in young animals, muscle weakness and bone decalcification.
Excess: Extremely dangerous and very common when feeding an animal “only meat” without calcium supplementation. It forces the body to extract the missing calcium from the bones, which results in their severe deformation, pain and brittleness. [2] [3]. Chronic excess severely and irreversibly damages the kidneys.
Sources
- National Research Council (2006). Nutrient Requirements of Dogs and Cats, Chapter 7 - Minerals. National Academies Press. https://nap.nationalacademies.org/catalog/10668/nutrient-requirements-of-dogs-and-cats
- Stockman J, Villaverde C, Corbee RJ (2021). Calcium, Phosphorus, and Vitamin D in Dogs and Cats: Beyond the Bones. Veterinary Clinics of North America: Small Animal Practice. https://doi.org/10.1016/j.cvsm.2021.01.003
- Böswald LF, Klein C, Dobenecker B, Kienzle E (2019). Factory calculation of calcium and phosphorus requirements of growing dogs. PLoS ONE. https://doi.org/10.1371/journal.pone.0220305