Originally Posted by Left Hand Percherons
Not uncommon for a horse as it ages to need more nutrients as they become less efficient at utilizing them.
...and as stores become lower & issues noticable, due to long term imbalances. And as long term digestive & other issues start to be chronic enough to effect health. And not just in horses. Nutrition is vital to health & if you wait till something's 'broke' before trying to 'fix' it, it can sometimes be too late.