11th November 2023

The market for supplements is huge and many owners find different supplements useful for caring for their horse but it is easy to become overwhelmed by the vast number of options available for your horse.

Manufacturers of supplements do not have to tell you how much of an active ingredient is present in their product and they also don’t have to run safety testing on their product or prove that it has any effects. With this in mind always approach the claims of supplements with a pinch of salt.

Most supplement ingredients have little scientific testing to show they work although some have been investigated more fully in people and other animals. 

Never give more of a supplement than is advised on the packet and let your vet know about any supplements your horse is on if they become unwell as some supplements may cause unexpected allergic reactions or side effects particularly when used with other medications.  Due to the lack of research it is difficult to say exactly what to look out for.

Joint Supplements

There are several ingredients which occur frequently in joint supplements. Supplements that contain more than one of the following have been shown to work better than one ingredient on its own. However, if you do want a joint supplement, make sure there is a high percentage of at least one these products in the product you choose:

  • Glucosamine: Involved in the formation of cartilage and joint fluid. Some studies suggest it can slow down damage to cartilage through mild anti-inflammatory effects.
  • Chondroitin Sulfate: A protein found in cartilage and joint tissues.
  • Hyaluronan (hyaluronic acid): An important part of joint fluid, tissue and cartilage.
  • MSM (methylsunfonylmethane): A source of sulfur, necessary to produce collagen found in joints.
  • Boswellia: Anti-inflammatory properties to help with chronic inflammation conditions.

Calming Supplements

Many people use calmers in their horse’s diet. Some of the ingredients in these supplements do have a long history of use in treatment of anxiety in people and work in a similar way to medical sedatives although much weaker due to low concentrations found in feed. For this reason, several ingredients found in calming supplements are banned for competing horses.

  • Zylkene contains a natural ingredient derived from a protein in milk. It has clinically proven calming properties in cats and dogs. Little evidence is available for its use in horses.

  • Inositol (vitamin B8) - A compound which aids cell membranes; research suggests that it can aid in treatment of panic disorders, bipolar depression and obsessive-compulsive disorder in people, but little evidence is available for its use in horses

  • Valerian - An extract from the dried root of a flowering plant contains compounds believed affect the function of nerves. It acts in a similar way to some of the seditives used by your vet making the nerves less responsive to stimulation. It is a banned substance for competing horses.

  • Passionflower - Works in a similar way to valarian and some veterinary sedatives reducing the stimulation of nerves. It is a banned substance for competing horses and although it has been shown to decrease signs of anxiety in some animals it may increase anxiety in others.

Potassium Bromide can be prescribed by your vet for excitable or nervous horses. It is used in humans and animal species to help treat anxiety and epilepsy by affecting the electrical activity of nerves through changing ion concentrations. It is not allowed for competing horses but has proved to be very safe when given long term. The advantage of using this over a supplement is that the quality and concentration of the product you are giving is checked.  However, a vet will need to see your horse before prescribing it.

Chasteberry aka vitex agnus-castus

Chasteberry has been used as a supplement to aid with hormonal behavioural problems due to its action on part of the brain involved with hormone production.

Recently it has gained popularity as an alternative treatment for the condition of Cushing’s in horses. Some studies have shown that it reduces the incidence of laminitis, excessive drinking, abnormal fat deposits and hair coat changes in horses with Cushing’s. However, it has also been shown that the abnormal hormone levels are not changed, and many horses will not improve and may get worse on this supplement alone.  The usual veterinary treatment for confirmed cases of Cushing’s is to give pergolide which has been proved to be more reliable and effective than Chasteberry in a direct comparison.

Another article talks about Cushing’s in more detail. If you think your horse has symptoms of Cushing’s, it is important to ask your vet to do an exam and a blood test for hormonal changes before starting any treatment or supplementation to their diet.

What should I look out for when buying a Supplement?

Always bear in mind that what works for one horse may not work for another and that the science behind many supplements is scarce. If trying out a supplement, try using it for a month and then stopping the supplement for a few weeks to see if you notice any affect in your horse before committing to using it long term.

If your horse is showing behavioural problems or signs of lameness, it is always recommended to ask your vet to examine them for any problems which may be causing them to act unusually. Getting treatment early on may reduce the amount of medication and cost long term.

Some supplement manufacturers have signed up to assurance schemes such as UFAS and the BETA NOPS code. They have logos for these assurance schemes on their boxes. In order to qualify, the manufacturers have to prove that their products contain the amount of ingredients they state and undergo product testing to check for contaminants which may affect the supplement. This means all their products have the same concentrations and should be as effective each time you use them.

To view/download a copy of this information in PDF format, please click here.

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