Author’s note: Recently I wrote a piece about when to put a senior horse on senior feed. The article received the following question from Dawn McClean and a related comment.

Q: I currently have a 16-year-old Arabian mare who was diagnosed with Cushing’s disease (pituitary pars intermedia dysfunction, or PPID) two years ago. Her dam had exactly the same issue at the same age and I lost her at age 18 to a stroke. In both cases, the muscle-wasting is quite pronounced and laminitis is a looming problem, yet I am hesitant to try feeding a senior feed. I do remember that my previous mare lost weight very quickly soon after the laminitis appeared, and I really do not want to see that happen with the current one. Are there any parameters for offering feeds designed for seniors in this case? She does clean up her hay, so that is not an issue. –Dawn McClean

A: This is a very important consideration for some horses as not all senior feeds are appropriate for horses with insulin resistance, equine metabolic disease or PPID. Feeds fed to these horses, especially those fed in large quantities such as a complete senior feed, need to have low non-structural carbohydrates (NSC). Ideally 12 percent NSC or less. Some popular senior feeds have NSC values well above that making them inappropriate in these cases.

For these horses there are other safer options. Some brands of senior feed have low enough NSC even though they might not market the feed as being low-NSC. This information is unlikely to be on feed tags and will require a visit to the company’s website or potentially a phone call to confirm