With spring a distant memory, you may think the risk of laminitis is well behind you. Don't be fooled by late summer's dried and sparse pastures, however. They can still precipitate the devastating hoof condition in susceptible horses.
Fructan is the sugar in grass that triggers metabolic laminitis. Although we commonly think of lush, green grass as the riskiest forage, fructan levels in pasture increase during times of stress and arrested growth, such as during a drought.
In addition, a flush of growth with the return of moisture, followed by noticeably lower nighttime temperatures, can set up conditions in which fructan levels rise. Fructan is found in cool-season grasses commonly used in pastures, such as bluegrass and orchard grass. It's important to note, however, that the type of grass doesn't have as much to do with fructan levels as the growing conditions.
If you have a horse who is at increased risk of laminitis—one who is insulin resistant or obese, for example, or has previously had the condition—remain vigilant throughout the late summer and early fall. This may mean keeping him muzzled a few weeks longer or moving him onto a dry lot. (Take this time to look critically at each horse's body condition and make other feed changes as needed, too.)
In addition, try to ride your at-risk horse regularly. Exercise can also help reduce the risk of laminitis.