Unusual Eating Behavior – Culprit Could be Salt Deficiency

Salt Block for HorsesUnusual eating behavior ( sometimes referred to as pica) can be caused by a number of factors and may cause the horse to eat manure, eat dirt, eat bark off trees, chew on board fences, chew on stable mate’s mane & tail or chew on tool handles or leather equipment.

I usually suggest going thru the following check list for the most common causes of unusual eating behavior:

  1. Lack of salt. Lack of salt can trigger a number of unusual eating behaviors (eating manure, chewing bark on trees, eating dirt, chewing on objects, chewing on tool handles etc.) Recommendation is to offer loose salt free choice as horses will consume more readily than block salt, particularly in cold weather. Block salt is better than not offering any salt source. Maintenance horses require 1-2 ounces of salt per day.  This may increase to 4-6 ounces per head per day in hot humid conditions or with added exercise.  Commercial feeds may contain 0.5% salt.  Horses may still benefit from salt being offered free choice along with access to fresh, clean water.
  2. Fiber intake in the diet might be inadequate. If a horse does not feel full, it will look for other things to eat. Make sure there is adequate long stem roughage available.  Fences, trees, manes and tails may suffer if there is not sufficient roughage!
  3. Phosphorus deficiency. Horses have quite limited “nutritional wisdom”, but phosphorus deficiency may trigger unusual eating behavior, including eating manure or dirt. Offering a free choice calcium, phosphorus and salt mineral may be useful.  In the wild, animals frequently consume bones or shed antlers to get minerals.
  4. Protein deficiency. Again, horses have limited “nutritional wisdom”, but inadequate protein or poor quality protein may trigger some of the unusual eating behaviors. Evaluating the forage and the overall feeding program is useful.
  5. Ulcers. Horses that have ulcers will sometimes eat dirt or manure as well as chew on other objects. The saliva produced when chewing is believed to have a buffering effect.

I always start by offering loose salt free choice and making certain that fiber intake is adequate. If that does not remedy the problem, I will then go to offering a good mineral product (calcium, phosphorus, salt combination, perhaps with some trace minerals) and perhaps a full ration evaluation.  Other behaviors may help decide if ulcer assessment is needed.

Unusual behavior may be the horse’s way of trying to tell us something!

Warm Temps & Water Consumption

The transition in temperature and humidity from cool season to warm season may require an adjustment in watering horses. Reduced water consumption may impair performance and may increase the risk of impaction colic. Also, horses that are not conditioned properly may sweat more profusely than a well-conditioned horse, and thus dehydrate faster. This is particularly important early in the season when temperatures may change suddenly and horses may not yet be in peak condition.

The first key element is to make certain that horses have ready access to clean, palatable, cool water at all times or at very frequent intervals. Horses will normally consume about 1 gallon of water per 100 lbs body weight, so an 1100 lb horse will require a minimum of 11 gallons of water per day. This quantity can increase substantially during periods of exercise, high heat/humidity or for lactating mares.

Some tips to keep in mind to keep water consumption up:

  • Horses do not like to consume warm water in warm temperatures. Automatic waterers or large tanks, located in the shade and cleaned regularly, may be good options. If water is supplied in buckets, they need to be cleaned regularly and re-filled regularly.
  • If you are traveling to a show or other competition, it is essential to monitor water consumption, particularly if temperature conditions change.
  • It is routine in many barns to flavor the water with something like wintergreen or peppermint at home so that you can flavor the water in new facilities to match the home water.  Read here for tips on training your horse to drink water away from home.
  • Do NOT use soft drinks or any material containing caffeine as these can trigger positive drug tests.
  • Taking horses to facilities with chlorinated water can sometimes reduce water consumption without proper precautions.

The second key element is to make certain that salt is offered free choice. Things to keep in mind for salt consumption in horses include:

  • Horses require 1-2 ounces of salt per day, and this can increase to 6 ounces per day with exercise in hot weather conditions.
  • Loose salt is consumed more readily than salt blocks in many cases.
  • When evaluating the total diet for salt consumption, commercial feeds normally contain 0.5-1.0% salt. It is not typically any higher than this, due to problems with palatability.
  • If a horse has been salt deficient or is bored, they may over-consume salt while in a stall.
  • Additional electrolytes, commercial or personal recipe, may be used per directions before, during and following completion, but care must be taken to ensure that the horses are drinking adequate water. Administering electrolytes to a horse that is not drinking properly, or allowing a horse to over consume salt without adequate water, can lead to electrolyte imbalances. If electrolytes are added to the water, plain water should be offered also.

Horses need to be offered water throughout the day at a competition, and should be re-hydrated following exertion. They cannot cool out and recover properly without being re-hydrated. Keeping horses properly hydrated and maintaining electrolyte balance is extremely important in order to make a safe transition from cool temperatures to summer time and competition.

Feeding Electrolytes to Horses

As a follow-up to our recent post on providing adequate water for horses, the following information should be helpful in understanding the use of supplemental electrolytes for horses.  There are a wide range of practices and opinions within this topic, so here are some basic guidelines to keep in mind:

  1. Provide loose salt free choice at all times to all horses.  If loose salt is provided, horses will usually consume the right amount to meet their electrolyte requirements without having to use an additional supplement. 
  2. Horses administered any form of electrolytes need to be consuming adequate water.
  3. Electrolytes should never be force fed to a dehydrated horse, and any horses supplemented with electrolytes should be monitored for dehydration (skin pinch test, mucous membrane color and hydration, capillary refill).
  4. Electrolytes can be used to encourage drinking (e.g. during transport or if horse doesn’t like to drink away from home).  Usually thirst/drinking is stimulated within 3-4 hours after dosing. 
  5. In cases where horses are working extremely hard and losing electrolytes through substantial sweating, a supplemental electrolyte in addition to the salt may be beneficial. 
    1. If heavy sweating due to competition is anticipated, administer electrolytes 1-2 days prior to competition, during the competition and 1-2 days after a competition. 
    2. Doses are usually within the 1 – 4 oz range, depending on sweat loss and the heat and humidity levels. 
    3. A general rule of thumb is usually 30 – 90 g per hour of strenuous work, or follow manufacturer’s instructions if using a commercial product. 
  6. An oral dose (paste/syringe) is recommended over top dress or adding to water, as these methods can create palatability issues and can result in feed/water refusal.
  7. Many commercial products have more sugar that electrolytes in them, so buying a commercial product where sugar is not listed as one of the main ingredients is very important.  Potassium, sodium, chloride, and calcium are the most important electrolytes.