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At first, this seems like there is an obvious answer to this question – No you shouldn’t breed a mare with kissing spines. Not only is this likely to put extra strain on the mares back, but surely she could pass this condition onto her foal. Or at least that was my initial reaction when I first saw someone asking this question on social media. However, after reading some of the comments, I think I have changed my mind.
To the best of my knowledge (when I did a project on it at Uni a few months ago) kissing spines is not heritable. However, there are close links between; breed, conformation and work type and the the horse developing this condition.
Surprise, surprise, thoroughbreds were found to be the most prone to developing kissing spines. It is therefore not surprising that racing had the highest percentage of horses with symptoms than other disciplines. Flat racing had a slightly higher percentage than national hunt horses. However, interestingly, dressage had the next highest percentage. Research has also found that horses with short backs are more likely to develop kissing spines.
So if you did decide to breed your mare with kissing spines, how likely is it your foal will develop kissing spines?
This, without further research, is virtually impossible to answer accurately. However, if you can determine (or at least have a good guess) why your mare has kissing spines, you may be able to reduce the likelihood of the offspring developing this condition.
If your mare is short backed, this may well be the reason for the kissing spines. Therefore, an ‘easy’ solution is to breed for a longer back in the foal, choosing a stallion with a longer back. Similarly, if your mare is a TB, or another breed which is ‘prone’ to kissing spines, choosing a stallion from a breed where the condition is less common would be a good way to prevent the condition in the foal.
It is thought racehorses are prone to kissing spine due to them working in an inverted outline/shape. Therefore, pushing the spinous processes closer together and increasing the chance of ‘kissing’. The thoughts behind dressage horses developing kissing spines is more linked to the unnatural twisting in the spine in lateral movements. These movements could be causing the kissing spine, although this is not proven. If your mare spent a long time not working through and over their back properly or has had a good dressage career, the kissing spines may have been caused by her work load and therefore is less likely to be passed on to the offspring.
Sometimes injury can lead to development of kissing spines. This is because, much like we limp, horses change their movement to avoid pain. This change in way of going could potentially cause the spine to ‘kiss’ and lead to this condition. As with type of work, if your mare has kissing spines due to injury, it is less likely to be passed onto her offspring.
As with all things involved in breeding horses, a large amount of luck and good management is required. If I was to breed from a mare with kissing spines, I would spend a lot of time getting the offspring to work through its back and building topline before being backed and during its training. This will strengthen the back and pull the spinous processes apart. However, there is no sure fire way to prevent kissing spines and even a horse with no history of kissing spines in its pedigree can develop this condition.
Now I have covered the likelihood of the offspring developing kissing spines, I’m now going to look at the big ethical issue of:
Is it fair to the mare to put her in foal?
When I first thought about it, I thought that surely the extra weight of the foal would pull on the spine, causing it to invert and cause more overlap to the kissing spines. Which in turn, leads to more pain and discomfort. However, interestingly, several people commented on this topic on Facebook saying that a kissing spines specialists suggested that they put their mare in foal and after putting the mare in foal, they quickly saw an improvement. This shocked me, but when they explained why, it started to make sense.
One of the most common treatments for kissing spine is to snip the ligaments, to allow more space between vertebrae. Putting a mare in foal (or giving pregnancy hormones) is said to loosen up these ligaments and therefore allows for more space and removes the pain.
I haven’t been able to find any scientific research supporting this idea, however, many people have said that their vet recommended it and have seen improvements since. So it is an interesting idea which sounds like it has some real potential.
So this Facebook topic has changed my opinion on breeding a mare with kissing spines. However, depending on the reason for the mares kissing spine and her potential usefulness as a breeding animal, using pregnancy hormones may be a better option than producing poor quality foals. I would personally be much more careful about how I managed a foal from a mare with kissing spines during its training than a foal from a mare without kissing spines. But this is something I think could be very useful to mare owners!