Yesterday I was plaing on my survival world. I found some horses so I brought back one. I wanted to visit my village nearby so I took my horse there. When I was done trading with villagers I took my horse and went back home.

I put my horse in his cage and dismounted him. The moment I got down I saw him somelike teleporting.
He just dissapeared before my eyes, so I came back to the village to look for him. Since he was not there I was heading back frustrated I lost my horse, he somehow appeard in his cage again. I was happy but at the same time really confused.
Today I was playing again and noticed my horse was missing again.But there was a shadow in the cage so I tried clicking. My horse was there, just invisible.

Now, I had a faithfull texture pack on this second time this happened and reloading the texutes by F3+T worked.
But, the first time it happened it didnt have the shadow, he wasnt there at all I had a deafult texture pack.