Horse Laxatives: Understanding Safe Administration

Laxatives are commonly used to treat colic in horses, which is caused by abdominal pain and gastrointestinal issues. The goal of treatment is to relieve pain and restore proper gastrointestinal function. Laxatives are chosen over other treatments as they increase the motility of the intestine and the bulk of feces, helping to clear blockages.

The dosage of laxatives for horses is usually based on human dosages, with some adjustments. Mineral oil, for example, is a common laxative for horses, but it is important to ensure the correct medication is being used as similar-looking containers can cause confusion.

There are several types of laxatives that can be used, including:

- Saline laxatives (e.g. magnesium salts, sodium salts)

- Lubricant laxatives (e.g. mineral oil, white petroleum)

- Bulk laxatives (e.g. methylcellulose, psyllium, prunes)

Mineral oil

The recommended dosage for horses is 2 to 4 quarts for adults and 0.5 quarts for foals. It can be administered orally and is safe for internal use. It is important to follow the instructions of a licensed veterinarian when using mineral oil or any other medication for your horse.

Epsom salt

Magnesium is important for muscle function, a healthy nervous system, strong bones, and healthy kidneys. It is also a calming agent, as it aids nerve and muscle function. Epsom salt can be added to a horse's feed to help with nervousness, but it should be noted that it can upset the balance of the gut microflora, so it should not be given to a horse with impaired kidney function or restricted water access.

When used as a laxative, Epsom salt should only be given for a short period of time, and it is not recommended for daily use as it can cause diarrhea. For treating fecal impactions, the dose is 1g per kg (approximately 1 pound of Epsom salt for an average full-size horse). This is usually given in 5-10 liters of water via a naso-gastric tube. This procedure should only be done by someone experienced, as the tube can be accidentally placed in the lungs.

Psyllium

The recommended dosage of psyllium for an average-size horse (900 to 1,100 pounds) is 2–4 ounces per day. Smaller equines, such as a 500-pound pony, should be given a smaller dose, while larger horses may be given a larger dose. It is typically mixed with water and added to feed.

There are various types of psyllium supplements available, including whole seed, granules, powder and pellets. It is also available as a dietary supplement for humans in the form of husk, granules, capsules or powder, and is sometimes added to breakfast cereals and baked goods.

Water

A horse's diet is typically high in fibre, including grass and hay, which requires high levels of water to help keep the fibre moving through the digestive system. Water also helps to prevent other digestive ailments and supports essential life functions. For example, water is needed for blood flow, tear production, mucus production, and waste removal.

The amount of water a horse needs depends on various factors, including climate, workload, and diet. On average, a horse at rest needs to drink a gallon (4.5 litres) of water per 100 pounds of weight every day. This means that horses need to drink between 5 and 15 gallons (22.7 to 68.1 litres) of water every day. This amount will increase in hot weather, as horses will sweat more, and if the horse is working very hard. A mare with a foal also needs more water, as she needs water to produce milk for her foal.

It is important to ensure that horses always have access to clean, fresh water. Horses have a delicate digestive system and are unable to vomit, so they must be able to drink clean water to avoid ingesting contaminated water, which can make them sick. Horses also have a good sense of smell and taste and may refuse to drink if the water supply is polluted, stagnant, or suddenly changes. Therefore, it is recommended to regularly scrub water buckets or troughs and to ensure that travelling horses have access to familiar water.

Dehydration can occur during strenuous exercise, in stressful situations, or if a horse suffers from diarrhoea. Signs of dehydration include red mucous membranes, excessive thick saliva, dark urine, and excessive sweating or no sweating. If a horse is dehydrated, it is important to offer plenty of clean, palatable water and, if necessary, call a veterinarian.

Sodium sulfate

The typical dosage of sodium sulfate for a horse laxative is 0.5-1 g/kg. It is important to note that laxatives should not be administered to horses with signs of proximal gastrointestinal obstruction, as this can be dangerous.

In a study on the influence of laxatives on gastric emptying in healthy Warmblood horses, it was found that a dosage of 1.8% sodium sulfate did not delay gastric emptying compared to water. However, a higher dosage of 25% sodium sulfate did cause a significant delay in gastric emptying.

It is important to consult with a veterinarian to determine the appropriate dosage and administration method for a horse, as incorrect usage can be harmful or fatal.

Frequently asked questions