Some nutritional problems of horses.

The effects of overfeeding, calcium-phosphorus imbalance, misuse of supplements and false advertising on equine nutrition are discussed. Overfeeding is known to cause disorders in several species but, although a similar relationship has been suggested on clinical evidence, no controlled trials on horses have been reported. It has also been suggested that overfeeding is a problem only for those horses with a genetic predisposition to skeletal problems. The importance of adequate calcium and phosphorus levels has been known for many years but severe cases of calcium deficiency still occur. Client education is important and should not be neglected. Excessive use of supplements containing high levels of trace minerals (eg, iodine and selenium) or fat soluble vitamins (eg, vitamin A and vitamin D) can be harmful. Some manufacturers advertise supplements in terms which may inadvertently or intentionally misrepresent their products. Supplements should, therefore, be selected carefully to ensure that they meet the particular requirements of the individual.