Equine Metabolic Syndrome: Feeding Horses for Weight Loss

Horses with equine metabolic syndrome are characterized by obesity, abnormal insulin dynamics, and a tendency to develop laminitis. Even though weight loss is desirable in these horses, that goal is often hampered by their inability to exercise due to laminitis-related pain.

In a research project* conducted by veterinary medicine faculty at the University of Ghent in Belgium, dietary restriction without added exercise was tried as a method of weight reduction in a 12-year-old Pura Raza Espanola mare whose diet was 90 minutes per day of turnout on lush pasture, 2.25 kg (5 lb) of hay, 450 grams (1 lb) of a dehydrated grass enriched with textured pellets made of oats and molasses, and 900 grams (2 lb) of a blend of low-starch grasses and linseed. She also received one apple daily. The mare showed foot tenderness, weighed 510 kg (1124 lb), and had a body condition score of 9/9 and chest circumference of 195 cm (77 in). She was diagnosed with laminitis and metabolic syndrome.

Treatment consisted of dietary restriction designed to provide 80% of the maintenance energy requirement. Weight loss goal was 1 to 2% per week. Ideal body weight was estimated as 360 kg (794 lb). Pasture access was eliminated, and the mare was given 4 kg (8.8 lb) of soaked good-quality hay and 1.5 kg (3.3 lb) of wheat straw divided into four daily meals. She was also fed a vitamin and mineral supplement, and had free access to water and a salt lick. She was bedded on shavings.

After six weeks on the dietary treatment, the horse had lost 70 kg (154 lb) of body weight and had a chest circumference of 182 cm (71.6 in). A month later, chest circumference had decreased to 179 cm (70.5 in). For this horse, dietary restriction resulted in significant weight loss even without increased exercise.

*This research was summarized in a presentation at the 7th European Workshop on Equine Nutrition.