EQUUS CONSULTANTS

A safe weight-loss plan

Q:How do you get an obese horse to lose weight without too much stress? I am adopting a 12-year-old gelding from a rescue group. He looks like he is in advanced pregnancy. You can’t feel his ribs, even when pressing down! He needs to go on a diet and start daily workouts, but I am concerned about the proper way to go about this without causing ulcers or other stress-related problems.

He will have daily turnout but will be in a stall at night and for breakfast. I am thinking of using a grazing muzzle but am worried this will add to his stress.

What are realistic milestones for weight reduction? In terms of exercise, what is a good balance so he will not get soured or sore, yet still lose weight?

Name withheld upon request

A:Obesity in horses is a very common problem but fortunately one that can be addressed with strict management.

The first step is to reduce the amount of feed he eats per day without jeopardizing his vitamin and mineral balance. If your horse is on an all-hay diet, this is relatively simple. Most horses need to eat around 2 percent of their body weight in feed (which is 20 pounds for a 1,000-pound horse). With an overweight horse, start by restricting his hay to 1.75 percent of his body weight for the first week, then go to 1.5 percent after that. The slow reduction will help decrease the stress of receiving less food. More drastic diets--restricting hay to below 1.25 percent of body weight---require the supervision of a veterinarian or equine nutritionist.

Researchers have observed that horses on restricted diets tend to seek

out alternative food sources and may begin chewing on wood shavings or fences. One solution for this problem is the use of slow feeders or slow-feed hay nets, which make a horse’s ration last longer by limiting the amount he can take in one bite. Recently, researchers determined that hay nets with medium (1.7-inch) and small (1.2-inch) openings were effective in decreasing both the rate and the amount of forage consumed by mature horses.

Another way to help a horse lose weight is to reduce the overall caloric density of his diet. For example, you could slowly replace a high-quality hay with a less calorie-dense hay (that is, a more mature hay or a blend containing more grass and less alfalfa). Unlike the caloric-restriction strategy, this approach does not dramatically change the total amount of forage the horse receives, and it may be less stressful for him.

Managing the feed intake of a horse kept on pasture can be a bit more difficult because it is hard to determine how much he is actually eating as he grazes. Still, you can restrict pasture intake in a couple of ways depending on your setup:

Turn the horse out in a dry lot for a portion of the day. By restricting access to pasture by six to 12 hours a day, you are reducing pasture intake by about a quarter or half. But be aware that some research has shown that horses who have adapted to this scenario may consume about half of their total dietary needs in only four hours. If limiting turnout time on pasture isn’t helping your horse lose weight, you’ll need to try a different strategy.

Keep the horse in a stall for a portion of the day. This option is less desirable than the dry lot, and it may be more likely to cause stress-related behavioral problems and/or gastric ulcers. If you go this route, providing a lowquality grass hay for the horse to munch on is probably better than leaving him alone in the stall with nothing to do.

Apply a grazing muzzle. A grazing muzzle is designed to limit access to grass while still allowing a horse on pasture to drink and socialize with others. This is a good option if you do not have a dry lot and the horse must be outside all day long. As with any management change, you’ll want to introduce the muzzle gradually.

The biggest concern with any of these strategies for limiting a horse’s food intake is the possibility that he might not get enough vitamins and minerals. Adding a ration balancer pellet to your horse’s diet might be a good idea. Ration balancer pellets are low in calories but high in protein as well as the vitamins and minerals that might be lacking in hay and/or pasture. These feeds are usually fed at roughly one pound per day and are around 30 percent protein. When added to a diet with hay and/or pasture, the total diet is about 10 to 12 percent protein, which is appropriate for a mature horse.

No matter which approach you take, dietary changes must be made slowly. Decide on your management strategy and implement the changes over the course of about one to two weeks to decrease any stresses. That is, gradually decrease turnout time, or increase the time the horse is muzzled on pasture.

Over the course of your horse’s new feed regimen, it is best to monitor his weight loss using a weight tape or by assessing his body0 condition score every two weeks. This will let you know if the horse is losing the right amount of weight or if you need to decrease turnout time even more. A healthy time frame for weight loss should be one body condition score or about 100 pounds in one month. Forcing weight loss to happen any faster could cause other behavioral or health problems.

Increased exercise is also a great way to help your horse reach an appro

priate weight. First, have your veterinarian assess the horse to make sure he is physically capable of the level of work you want to do. A good starting regimen for a horse who hasn’t been exercised is to walk 10 to 15 minutes three to four times a week. This duration can be increased the following week.

When the horse can comfortably handle 40 minutes of walking, add some two- to three-minute intervals of trotting three or four times during each workout. You can also add work on hills and other varying terrain at this time to help encourage your horse to use more of his body. This will increase the calories burned and help build muscle. It would be a good idea to consult with a trainer so you can maximize the amount of calories burned in each workout without overdoing the amount of exercise your horse can handle.

Once your horse has reached his target weight, you will need to slowly increase his pasture or feed intake so he can maintain it. However, you’ll always need to monitor his body condition. You wouldn’t want to have to start the weight loss process all over again. Carey A. Williams, PhD Rutgers, the State University

of New Jersey New Brunswick, New Jersey