BASICS
Serum P concentration less than reference interval.
- P is one of the most abundant elements in the body, with >80% found in bone and complexed with Ca2+ in the form of hydroxyapatite
- P, the major intracellular anion, is an important component of nucleic acids, phospholipids, and phosphoproteins
- Maintenance of cellular integrity and metabolism depends on phosphate-containing, high-energy compounds (e.g. ATP) and enzyme systems that require P
- Skeletal-associated abnormalities (e.g. demineralization, deformation, poor growth) are potential consequences of hypophosphatemia
- Depletion of ATP can affect any cell with high-energy requirements; erythrocytes, skeletal muscle cells, and brain cells are especially susceptible
- CRF—weight loss, PU/PD
- Dietary P deficiency—poor growth, lameness, anestrus, irregular estrus, reduced fertility
Serum P concentration in horses with CRF may be normal or low, depending on the presence and degree of hypercalcemia.
P deficiency or starvation. When caloric intake is increased, malnourished horses may develop complications associated with refeeding syndrome owing to increasing requirements for P; this necessitates close monitoring of serum P concentrations.
- Young, growing animals with vitamin D deficiency may be hypophosphatemic, hypocalcemic, and have elevated ALP activity
- Vitamin D deficiency causes defective mineralization of new bone, resulting in painful swelling of long bones and costochondral junctions, bowed limbs, and stiff gait
- Sepsis may lead to hypophosphatemia, probably owing to redistribution of P from the extracellular fluid compartment
- Respiratory alkalosis, insulin administration, and parenteral nutrition may cause hypophosphatemia
DIAGNOSIS
TREATMENT
MEDICATIONS
MISCELLANEOUS