NEW BRUNSWICK, NJ (April 25, 2012) – The recent drought experienced in New Jersey with subsequent rains warrants owners of horses prone to laminitis to take extra care when giving the animals access to pasture.
Basically, very dry conditions can lead to unusual accumulation of sugars and starches (non-structural carbohydrates or NSC) in pasture grasses that may trigger founder or laminitis, especially if the pasture is overgrazed and the grasses are very short. Rain and cool weather over night increase the risk even further for a few days. This is due to enhanced photosynthesis response to the increased moisture which causes even greater accumulation of NSC in the plants during the day but reduced conversion of these potentially problematic compounds to innocuous fiber overnight if the temperature is less than 40 degrees Fahrenheit. Sugar and starch content is usually lowest in the early morning (0600-1000h) but still may be problematic if it was cold overnight. It would be prudent to restrict obese and laminitic horses access to pasture to the early morning hours or perhaps avoid access totally for a day or two during rainy periods with cold nights after a drought like we have experienced recently.
Additional information can be found within “Ask the Expert”.