Pros & cons of mare hormone management

Which hormone management techniques allow mares to be at their competitive best? H&H investigates


Regumate is a synthetic progesterone-containing medicine that suppresses the behavioural signs of oestrus. It is administered orally on a daily basis.


• Proven to be the most effective hormone suppressant

• Now allowed under FEI rules (although paperwork must be completed with the FEI vet prior to competition)

• Should not compromise long-term fertility


• Costly — in the region of £30-£40 for a two-week course

• Must be given daily

• High risk of cross-contamination

• Must handle with care


Mare-bles are glass marbles placed in the uterus to manage behavioural problems. It is thought that the marbles mimic pregnancy in the mare.


• Does not rely on medication

• When it does work, it is effective and does not appear to cause discomfort to the mare

• No risk of the cross-contamination you could get with some medication


• Not widely available in the UK

• Not always effective

• Undetectable from the outside, so could cause problems when horses change ownership

• Risk of uterine inflammation

Natural/herbal/homeopathic supplements

Various alternative remedies which are usually in the form of dried herbs or liquid added to feed.


• Cheap compared with Regumate

• Should not compromise long-term fertility

• A wide variety of products to choose from


• No ‘hard’ science to prove they work

• Risk of some of them containing banned substances

• Their effectiveness can vary greatly from mare to mare

For the full article on managing competition mares, see the current issue of Horse & Hound (1 July, ’10)

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