I am posting this situation on behalf of a third party:
She has a two year old mare that she had a vet palpate to see if she was cycling as she is very agressive and the lady thinks she could possibly have a hormone imbalance...
The vet told her that she " could not find a Uterus or Overies, said her cervix is small and tight - hard. Says she doubts this mare will never be breeding sound." Does this sound right? Can mares be born this way?
There is a condition referred to as a "gonadal dysgenesis", where an offspring receives an abnormal number of chromosomes. This can manifest itself as an apparently normal (externally) mare, but internally an immature (or absent) reproductive tract.
To get a definitive answer on whether this is the situation, a special blood test called a karyotype can be performed, where the chromosomal value of the animal is evaluated.
In most cases, these animals will not be breeding sound (very rarely they may be, but almost never), but many may be used as "jump" or "tease" mares if hormonally manipulated for semen collection in AI programs.
I should add that not all 2-yo fillies will be exhibiting a fully mature reproductive tract (indeed a good percentage will not), so evaluation of a young animal's tract such as this, that exhibits apparent lack of growth should not be automatically labelled a gonadal dysgenesis - she may just not have gone through puberty yet, and is not yet sexually mature!
How common is this with mares? Is it related to certain bloodlines or anything like that? One person suggested that horses that are inbred/linebred are more common to show this, is this true?
Please note that opinions, product information, advice or suggestions posted on this bulletin board are not necessarily those of the management at Equine-Reproduction.com nor does the maintenance of the post position indicate an implicit or any endorsement of that information, opinion or product.
Further, although we have the greatest respect for the posters offering assistance here, you are advised to seek a consultation with your veterinarian prior to using information obtained from this board if it is of a veterinary nature.Proud to be sponsored and supported by: