The first step in any case of chronic weight loss is to examine the management and nutrition of the horse. Though management often effects all the horses present you cannot rule it out if only one horse is thin. Both the old and the young have increased nutritional needs while being more sensitive to the effects of parasites. Some adult horses just require more feed than others. In one study of similar sized horses doing similar amounts of work there was a 3 times increase in feed requirement to maintain the least efficient horse in the same condition as the most efficient horse.

A horse's need for calories and protein also change in response to temperature, work, grazing conditions. The first consideration given to a horse that has no other signs of disease and a good appetite should be the quantity and quality of his feed and the presence of intestinal parasites. Now is a good time to review these important management factors:

• Overview of Feeding Horses
• Overview of Forages
• Overview of Deworming Horses

Other related management factors that may cause weight loss:

• Teeth Problems: Have the teeth checked...more
• Underdosing the dewormer, using ineffective dewormers, not managing for minimizing parasitism. Be sure to use a weight tape and add an extra 100 lbs of the dewormer to the reading and follow the recommendations in the deworming section for effective products...more.
• Placing the feed on the ground: This practice can lead to sand accumulation in the bowel...more.
• Too much competition for feed: Feed horses their concentrate separately and with hay in the field be sure to have enough feeding stations that every horse can eat when he wants.
• Decrease feed intake do to nervousness: This is particularly common in horses during their first few weeks after being moved to a new home or changes in pasturing or pasture buddies. Do what you can to put your horse at ease and be patient he will settle down.
• Grains, particularly corn, contaminated with mycotoxins will cause both weight loss and a decrease in feed intake: Mycotoxin contaminated grain may appear normal and not have obvious mold. Poor or prolonged storage, broken grains, signs of mold, or the horse refusing to eat all its concentrate with grain in it all should be a red flag. Though individuals might be particularly sensitive if everyone who eats this grain is effected this should also raise suspicion. Feed can be tested usually by your local extension service.
• First-time experience with a hotter breed that may require more feed: Thoroughbreds are particularly difficult keepers compared to other breeds and if you are used to feeding quarter horses you may be surprised at the amount of feed required particularly of animals used for reproduction.
• It is well-recognized that as horses go over the 20-year mark maintaining weight frequently becomes harder particularly for those effected with Cushings Disease...more.

Any weaknesses in your management should be noted and corrected. If correction of management problems does not result in improved condition within 3 weeks or if no problems are found, the horse should be put on a aggressive feeding and deworming program.

Forage is the largest component of a horse's diet and the most variable in quality so deserves the first and closest look. A common cause for weight loss in horses is simply too little or too poor a quality forage. Even large amounts of a stemmy poor quality forage can result in poor condition. Make sure a excellent quality grass or grass/alfalfa forage is available free choice. If the horse is in a pasture competing with other horses be sure there are enough feeding stations to insure everyone can get hay when wanted. The hay should be fed up off the ground and even better is to be sure it is protected from the rain.

Alfalfa

Feeding Horses with Poor Dentition

If there are large improvements made in the forages, that alone may reverse the weight loss. If 3 weeks go by without improvement however the concentrate should be addressed.

For difficult keepers a high quality pelleted or extruded complete feed with at least 10% stabalized fat should be used. Alternatively you can consider adding fat, most often in the form of vegetable oil to the diet ...more.

If alfalfa is fed as a forage, a 10% protein concentrate is fine. But with grass forages use a 14%-16% protein concentrate. Do not dilute the complete feed by adding in corn or oats as this will decrease caloric, protein, mineral, and vitamin density. You should spend several weeks changing over to the new feed by slowly adding it to the existing concentrate. Then decreasing the current feed as you substitute the new feed, see insert for more. Research has shown that when grain based concentrates approach 4 lbs a meal per 1000 lbs of bodyweight that there are increasing amount of soluble carbohydrates reaching the large bowel where it causes bacterial blooms. If this level is approached you should further break down meals into extra feedings to keep the total below this amount per meal or switch to a beet pulp or alfalfa based concentrate.

Example of Changing Concentrate to a Pelleted or Extruded Feed: Let's say you are feeding your 1000 lb horse 2lbs of a sweet feed twice daily. Start by adding in a pound of the new feed at each feeding. After a week add in another lb of the complete feed so that now you are feeding 4lbs daily (2 sweet feed / 2 pelleted feed). After a week of that substitute a lb of the new feed so that now you are feeding 1 lb sweet and 3 lbs of pelleted feed. I would now use up the remaining sweet feed and when you give out put in 4 lbs pelleted feed. Of course at anytime if your horse starts gaining weight you should not continue to increase the amount of feed just begin substituting the new for the old until the old is used up.

As long as your horses' environment has a good consistent history of all the horses being dewormed regularly with efficacious products for the past year there may be no reason to deworm more aggressively than suggested in our schedules. There is a small population of horses that do have problems with even normal worm burdens on the pasture. They seem to be more susceptible to picking up and harboring parasites than their pasture mates. Regular fecals done just prior to a deworming will help identify these individuals.

If your difficult keeper is being kept on pastures with horses that are not being dewormed regularly he will benefit from the daily use of pyrantel if the product has not been used on the property for the past 3 years. We know resistance to the daily dewormers forms rather quickly. If this is the situation, yes put your horse on it but also be looking for a better pasture situation to move your horse to.