Marbles

Would you please address the use of 'marbles' in mares as a form of equine contraception? Is it safe? Is it effective? How long can they be used? When should they be placed? MayWould you please address the use of 'marbles' in mares as a form of equine contraception? Is it safe? Is it effective? How long can they be used? When should they be placed? May

Story originally posted by: Michael Lowder, DVM, MS

Hi Dr. Lowder,

Would you please address the use of ‘marbles’ in mares as a form of equine contraception? Is it safe? Is it effective? How long can they be used? When should they be placed? May they be used in maiden mares? What kind of marble should be used, and how is it placed?

I have been having a difficult time finding much information about this method. Most folks I’ve spoken with say they have never heard of it. I did talk with my own vet, and he says he has never had any experience with it either.

Thanks,

Joy

Joy,

There has been SOME evidence to show that putting glass marbles in some mares will "fake" the uterus into thinking that it is pregnant (early pregnancy). The marbles have to be sterile and place with the utmost care. They can be left in the uterus for about 30-45 days depending upon the mare and will have to be removed. Regumate is a better option.

Thank You,
Dr. Lowder