Question
My seven-year-old Andalusian gelding (16.3 hands; 1,400 lb or 640 kg) is in moderate body condition (score of 5). I show in low-level dressage but also trail ride a lot. Right now, he is stalled 19 hours, in the drylot four hours, and in the pasture for an hour. As grass growth slows, he will be on pasture completely when he’s not stalled. He’s fed grass hay, 2 lb (0.9 kg) of a low-starch feed, a protein supplement, and a four-in-one supplement for hoof health, joint support, antioxidant relief, and probiotic. He came up lame recently, and the vet found minor inflammation of a stifle. Radiographs showed an OCD lesion as well as possible calcium deficiency. While the vet addresses the stifle, can you review his diet for possible calcium deficiency?
Answer
The current diet contains sufficient calcium, but previous diet and management during the critical period for onset of growth disorders may have been factors that led to the development of OCD (osteochondritis dissecans).
While providing sufficient calories to maintain moderate body condition, his current diet is not supplying optimal nutrition. This can be corrected by increasing the amount of concentrate fed to meet the manufacturer’s recommendations (but weight gain may be an issue) or supplementing with a protein, vitamin, and mineral supplement. Instead of the current protein supplement, I recommend offering a ration balancer, a specific class of feed designed to supply high-quality protein as well as key minerals and vitamins to balance the diet. Further, I suggest adding the bone supplement Triacton to his diet, as it contains a highly digestible source of calcium and other bone-building nutrients.
The forage analysis you provided on your hay was helpful. The hay is moderate quality based on the protein content and fiber levels (acid detergent fiber [ADF] and neutral detergent fiber [NDF]), so I would expect you to notice improvements to the gelding’s overall health and condition with the addition of a ration balancer and longer grazing periods.
Limited access to pasture is often necessary for managing the health of the horse and pasture. A longer grazing period during the summer, as you mentioned, will allow increased nutrient intake. Some horses will significantly increase their grass consumption when allowed to graze for short periods of time, so weight changes should be monitored closely. Limited access to pasture throughout the year can lead to low vitamin E status in horses, and this is best addressed with blood work and supplementation with a natural-source, water-soluble vitamin E product like Nano-E.
