California Riding Magazine • October 2013

Ask the Vet:
Horse on diet still gaining weight

by Lydia F. Gray, DVM, MA

I have a laminitic, overweight 5 yr. old Arabian mare. Have her on sparse paddock 24 hrs/day. Feed her 1 cup oats with tablespoon of omega 3, 6, 9 soy oil and vitamin/mineral supplement twice/day. Also, hay for 30 minutes/twice per day. She has lost some weight but, seems to be gaining again. My question is....could I just stop feeding hay to her? I feed the oats as a vehicle for the oil and vitamin/mineral supplements. I am concerned about her emotional state if I were to keep her on a dry lot out of the paddock. Am in the process of building a track to reduce her access to forage but it is taking more time then I had hoped. Seems she is gaining weight on the little stubble in the paddock. It is early spring and warm but she isn't shedding like her mom and has gone into early estrus...this concerns me also. Maybe early estrus is normal for some mares, I don't know but the oil I give her probably has estrogen in it. Could the oil cause an imbalance? Thank you...Jane

Dear Jane,

I’m going to start with your most pressing question first, “could I just stop feeding hay to her?” Unfortunately, no. Long-stem forage should be the basis or foundation of every horse’s diet, and you should provide a minimum of 1% (preferably 2%) of her body weight each day in high quality roughage. This means weighing your horse AND weighing your hay, two things you should probably be doing anyway, given her health issues.

Some options for safely feeding hay to the overweight horse are 1) to have your hay analyzed-- especially for sugar and starch content--then soak if necessary to remove these simple carbohydrates and 2) to offer the hay in a small hole hay net or other device which slows down her rate of consumption. I would rather see her eating small amounts frequently than be restricted to only 30 minutes twice per day of hay.

A grazing track works for some horses but if your mare is gaining weight just on the stubble in her “sparse” paddock, it may not be the best solution for her. Some owners of tremendously easy keepers have gone as far as to till up grass pastures and even paddocks with a hint of green so that their horses still receive turnout but no access to live plants. A second alternative is to use a grazing muzzle when she is turned out where there’s any grass. A few pony owners have even taped over the hole in the bottom of the muzzle so that their overweight equines don’t get ANY pasture.

I like that you’re feeding a vitamin/mineral supplement but recommend you cut out all grains, including the one cup of oats. Many “multi-vitamins” come in pelleted versions that are tasty enough to be fed alone. However, omega 3 fatty acids are a nice addition to her diet for their support of cell and tissue health. Since you’re concerned about potential unintended effects from the oil, perhaps you could switch to flax seed, chia seed or fish oil so she still benefits from these healthy fats. I hope some of these ideas help you two get on the right track!

Article provided by SmartPak.
Dr. Lydia Gray is the Medical Director/Staff Veterinarian for SmartPak, where she guides research and new product development, answers questions on her Ask the Vet blog, and speaks around the country at various events such as Equine Affaire, Dressage at Devon, and the USHJA Trainers’ Symposiums.