Updated: Mar 13
Certain conditions of the ovaries may appear to be a lameness problem. Most of these mares will show signs very similar to vaginitis as already discussed in a previous blog. However the condition does have its own individual characteristics.
Usually the problem is an ovarian cyst or retained follicle. The conditions are actually one and the same, the cyst simply being more severe. A cyst is an egg (follicle) on the ovary that refuses to fall off and move down the reproductive tract towards the womb, instead it remains firmly attached to the ovary, getting larger and larger, until it is an immense fluid filled sac, the size of a hardball or even bigger. The larger the cyst becomes, the more painful it becomes, and therefore the more apt it is to alter the mare's gait.
It is not uncommon for these mares to get heavily one line/rein but demonstrate no apparent lameness in their movement. As well, there appears to be no correlation between the line/rein and the affected ovary. Mares with left ovarian cysts are commonly on the right line/rein. A hunched appearance is more common in mares with ovarian problems than with vaginitis. Examination of the mare will usually reveal an area of soreness over the back between the front of the whirlbone and the muscle between the hip and midline. The definitive diagnosis is attained by examining the ovaries rectally. Once diagnosed, the mare is treated with hormones which will cause the cyst to fall off the ovary. If repeated hormonal treatment has failed, then surgical removal of the affected ovary may be required.
Some mares may even exhibit personality changes when an ovarian cyst is present. Many animals will seem to be continuously in heat. Others can become "bitchy", continuously nasty, some so bad that their actions seem more like an ugly stud horse than a mare. Others can become extremely quiet, so placid that there appears to be a complete lack of interest in life. It should be noted, that the mean mare is more common.