In 2019, Sheldon et al. published a paper entitled “Effects of magnesium with or without boron on headshaking behaviour in horses with trigeminal‐mediated headshaking”. They investigated supplementation with magnesium alone or magnesium and boron and found that whilst magnesium alone significantly reduced headshaking, magnesium plus boron was even more effective.
Unfortunately, whilst in the USA, for example, where the study was conducted, it’s possible to buy supplements with boron in, in the UK and Europe boron is not a permitted feed additive or feed material, so companies cannot legally sell supplements containing boron.
If we look in detail at the study by Sheldon et al. (2019), we can see that the supplements they used delivered either 2.7mg/kg body weight (BW) of elemental (pure) magnesium (equivalent to 24.2 mg/kg BW magnesium citrate as only 11.2% of magnesium citrate is elemental magnesium) or magnesium plus 2mg/kg BW elemental boron (equivalent to 40mg/kg BW of boron citrate as only 5% is elemental magnesium).
So, if you wanted to buy magnesium citrate and boron citrate and feed it to your head shaker, how much would you need to feed, and what would it cost you?
|mg/kg BW||Weight of horse (kg)||g/day|
If you have small range scales then you could weigh this out, but an alternative is to measure the volume.
So, for magnesium citrate, it would be around ¾ of a 25ml scoop per day and 1 x level 25ml scoop of boron citrate per day for a 500kg horse.
If you want to work out the amount for any other weight of horse, then simply divide the g or ml per day by 500 and multiply by the weight of your horse. E.g. for a 320kg pony, 12.1 g/day magnesium citrate divided by 500 = 0.0242 x 320 = 7.7 g/day or 12ml (just under half a 25ml scoop).
So what is this going to cost?
I found magnesium citrate from Life Lab at £21.89 for a 1000g pouch. So the cost for a 500kg horse at 12.1g per day would be £21.89/1000*12.1 = £0.26 per day or £7.95 per month. www.lifelabsupplements.com
Boron citrate is a little more challenging. In the UK/Europe, I could only find boron citrate tablets or capsules and these would work out way too expensive. The only reliable source of bulk boron citrate I could find was from the USA from a company called Bulk Supplements.com.
For 500g and 7-21 day delivery this worked out at £44.65 for 500g. So for a 500kg horse per day the cost would be £44.65/500*20 = £1.79 per day or £53.58 per month.
If you know a source of bulk boron citrate in the UK or Europe please let us know. So, in total, 12.1g magnesium citrate and 20g boron citrate together for a 500kg horse for 1 month would work out at £61.53 per month! It’s not cheap, but it’s in line with the cost of many equine supplements.
If you do have a horse that headshakes, please do talk to your vet and get a proper diagnosis. There are many other problems that can cause horses to headshake, such as dental disease for example. Feeding magnesium and boron to these will not help. If your horse is an idiopathic (no obvious cause) headshaker than it’s well worth trying magnesium and boron.
- You should consult your vet before placing your horse or pony on these medications.
- Magnesium citrate may cause gut irritation and diarrhoea. If this occurs, contact your vet.
- These are human supplements not equine supplements and effects of long-term use in horses not currently known even though at this time there are no known reported side-effects.
- The regulations in the USA on supplements are much less stringent than the UK, so you should be aware that products may be of a lower quality than advertised. Buyer beware.
The paper that describes feeding magnesium and boron is available open access (no charge to read the full paper) Sheldon SA, Aleman M, Costa LRR, Weich K, Howey Q, Madigan JE. Effects of magnesium with or without boron on headshaking behavior in horses with trigeminal-mediated headshaking. J Vet Intern Med. 2019 May;33(3):1464-1472. doi: 10.1111/jvim.15499. Epub 2019 Apr 16. PMID: 30990929; PMCID: PMC6524471.