But then there is the case where the owner KNOWS that the time is coming soon, but as long as the horse is showing enjoyment in his/her life the owner lets the horse live on.
My riding teacher had an Arabian mare that she had raised from birth. She LOVED this mare above all other horses. Well the mare’s front pasterns got worse and worse, sagging down distressingly. She told me that she had asked the mare to tell her when it was time to go, but no matter how bad the mare’s pasterns got the mare never told Debbie it was time, even though it was getting obvious.
Now I had not had a relationship with this mare when Debbie told me this, so I politely went up to the mare, told her what Debbie had told me, and I got a very brief picture of Debbie collapsing from grief, and that the mare did not want to see this happen. So I told the mare that if she told ME when it was too much for her to go on then I would tell Debbie and bear the initial spate of grief.
So I started going up to the mare every time I was at the stable, and I noticed that her back looked scruffy so I started currying her back. Soon the mare would come up to me and stand athwart me so I could curry the itchiest part of her back, and she showed every sign of enjoying it. This went on for several months.
One day the mare came up to me, and stopped facing me. When I went to curry her back she pivoted so she still faced me. I THOUGHT this might be the signal but I was not sure because the mare did not speak to my mind. I told her if she did this the next week I would be sure about her wanting to exit life because it had just gotten too burdensome.
The next week the same thing happened. She came up to me, faced me directly, and did not let me curry her back.
I told Debbie, she cried, she called the vet and made arrangements for getting the grave dug but was too upset to be there when the vet came. So her husband got the mare and led her to the already dug grave (it had a slope down), and the mare willingly walked into the grave and the vet put her down. This mare did NOT like going into strange looking places, but this time she just went ahead, laid down, and stopped hurting.
So no, not all horses will “tell” their owners that it is time to go even when it is long past time. Some other human has to step in and communicate the truth that the horse wants to stop suffering. Like many humans some horses feel a deep sense of responsibility for the well being of their favorite human and do not want to hurt that human’s mind/emotions grievously, and someone else has to step in and act as a go-between between the horse and its owner.