Preventing autumn grass colic in your horse

Why autumn grass is so dangerous

As soon as night-time temperatures drop below five degrees, grass stops growing but continues photosynthesising. The sugars it produces — particularly fructans — accumulate in the grass stem because they are no longer used for growth. On cold, sunny days in October and November, fructan levels can be three to four times higher than in summer. Horses cannot digest fructans in the small intestine; they pass directly into the caecum, where they ferment rapidly. This disrupts the bacterial population and significantly increases the risk of spasmodic or gas colic.

Risk factors that increase the danger

• Pasture with short, closely grazed turf — it is precisely the grass stem that contains the highest fructan levels
• A horse that spent the summer stabled and is unaccustomed to pasture grass
• EMS or insulin-resistant horses react more quickly to sugar spikes
• Sudden weather change: from warm and overcast to clear and cold within 48 hours
• Reduced water intake during the transition to cold weather increases gut sluggishness

Smart pasture rotation and timing

The simplest measure is to let your horse out only after 14:00. In the morning, fructan levels are at their highest because the grass has spent the night without sunlight but in the cold. After midday, levels have generally dropped. Limit grazing time during hard overnight frosts (below 2°C) to a maximum of two hours. An electric tape that divides the available pasture into sections gives you direct control without major investment. Rotate sections every three to four days so the grass does not get grazed too short.

Roughage as a buffer before turnout

Always give your horse hay or haylage before it goes outside. A stomach with a good roughage buffer slows gastric emptying and reduces the speed at which fructans reach the intestine. Aim for a minimum of one kilogram of dry matter per 100 kg of body weight as a daily roughage base, in addition to pasture grass. Never turn your horse out on a fructan-rich pasture on an empty stomach.

Signs to recognise early

• Horse looks at or bites its flanks shortly after returning from pasture
• Visible or audible gut sounds, restless pawing
• Rolling or lying down without apparent reason
• Reduced appetite immediately after grazing
• Elevated heart rate above 48 beats per minute at rest

Record patterns in your horse profile

Colic rarely comes completely out of nowhere. If you keep track of when your horse was affected, how long the grazing session was, and what the daily temperature pattern looked like, you will quickly spot a pattern. In the EquiSight horse profile, you record health notes, grazing schedules, and vet consultations all in one place. EquiCoach alerts you when you have logged multiple colic incidents within a short period and provides targeted points of attention for the following autumn. This way, you build up a more precise picture of your own horse's sensitivity every year.

Plan the transition to stable feeding

Switching too quickly from pasture grass to roughage only? That disrupts the gut bacteria just as much as a fructan spike. Gradually reduce grazing hours over two to three weeks: start by cutting back one hour per day. Add extra hay beforehand so that total roughage intake remains constant. Use the calendar in EquiSight to schedule a step-down plan with reminders, so you can maintain the routine even during busy working weeks.