Q: What type of hay should I feed my horse? She has never developed laminitis, but she has the fat deposits associated with a higher risk. She isn’t overweight or underweight. Is it better to feed her grass hay higher in nonstructural carbohydrates (NSCs) or alfalfa lower in NSCs but higher in calories? Currently I feed equal amounts of both and no grain.

A: From what you have told me, I wouldn’t change a thing. Your horse is in good body condition; she is doing well on the grass/alfalfa-mix hay you are currently feeding. She is getting no grain, and she has never developed laminitis, inflammation of the soft connective tissues within the foot that can result from a variety of causes, including a diet too rich in NSCs. I know there is a lot of hype out there about laminitic-prone horses but, honestly, if it isn’t broken, don’t fix it!

In Oregon your hays might have higher NSCs than the common ones we see here on the East Coast, but if they have not caused your mare a problem in the past, I would not expect it to happen now. Just because she has a pattern?of fat distribution typical of certain laminitis-prone breeds (Arabians, Morgans and Quarter Horse types, for example) does not mean she is in imminent danger of developing the disease, especially given that other risk factors are low: You are feeding no grain and did not even mention pasture access.

Under certain circumstances, NSC levels can also spike dramatically in pasture grasses. If your mare does have access to pasture, you might want to limit her grazing time to the morning hours, around 5 a.m. to 11 a.m. Also keep your mare off pasture if it freezes after a sunny day or if it heavily rains after a period of drought.

Sarah Ralston, VMD, PhD, DACVNRutgers, the State University of New Jersey New Brunswick, New Jersey