Can you tell if your horse is drowning?

Can you tell if a horse is drowning? Do bubbles appear like your air? How long will it take for the horse to drown?

You can not detect that a horse is underwater - there is no bubbles indicator or anything. When it begins to drown, it obviuosly flashes red, neighs and stands up.

Just like a player, a horse will take 15 seconds to start drowning. Drowning itself deals one heart of damage approximately each second (maybe faster) - how much a horse has left is clearly visible, if you are mounted on it.

Important detail: a horse is less than two meters tall, but you are able to make it walk in two meter deep water. Despite the horse still walking, it will already drown at this depth. So, while crossing 2 meter deep rivers is perfectly fine, care must be taken when navigating swamps or lakes - if a horse starts to drown, dismount immediately and let it swim up!