Q: Should I go treeless?
A: The tree of a saddle is generally considered pretty fundamental in that it helps to balance the rider and distribute the pressure and forces generated over the horse’s back to where they are supported by the ribcage. It follows therefore that the risks of a treeless saddle are that it can concentrate the pressures that the tree serves to spread. Concentrating pressure into small areas, particularly areas where stirrups are hanging, girthing attachments are found or the rider’s seat bones are located, can cause pressure points which are uncomfortable and potentially damaging to the horse’s back.
Overall pressures in a treeless saddle are often claimed to be lower than in a saddle with a tree, and while this may be the case, the treeless saddle spreads the pressure over a much smaller area than the saddle tree. The pressure from the treeless saddle is therefore concentrated, and more likely to cause issues.
Often horses will initially go a bit better in a treeless saddle, leading to some owners raving about them, but the damage that is ultimately caused by the concentrated pressure builds up so that after a few months the horse is likely to be found to have a sore back, and atrophy of the muscles in certain areas. Not all treeless saddles are like this, but the majority are. You really need to do your research to ensure that you get the right treeless saddle if this is the route you choose to take.
The one exception, where treeless saddles can be very useful and often recommended, is in overweight horses, where they need to be ridden to assist their weight-loss programme. If a horse is so obese that fitting a saddle with a tree is difficult as the bars on adjustable saddles are simply not wide enough, the fat over his back will often give him sufficient protection to avoid any discomfort from the treeless saddle, at least in the short term. You can therefore ride him in a treeless saddle until his weight is such that he can be fitted for a different saddle. You may also get away with a treeless saddle in horses that are infrequently ridden and who are ridden at a low intensity.