This provokes me pretty confusing feelings. On one hand, I don´t see nothing wrong on a zoo killing the animals they need to feed their carnivores. But on the other, I don´t like how that makes easy for people to get rid of their animals whenever they want. To me, sounds like "are you tired of your pet? Don´t worry, we´ll help you to get rid of it!".
Anyway, I´d need to know the details. Also if in Denmark horses are mainly keep as hobby or if people use them for work. I guess the ones breed for human consumption won´t be donated for this.
As a horse owner currently facing the possibility of needing to say farewell to a much loved horse and is considering doing this, maybe I can help clarify why many of us would chose to do this.
Firstly, horses are incredibly expensive to have put down. In my area of my country the vet has to come to the farm. Most use the same drugs that are used on dogs and cats, just in much larger doses. The vet visit alone is very expensive. Afterwards, you need to pay for someone to come remove the body. Very few owners have the equipment or resources to bury on the property, and most people board their horses at stables, so most stable owners don't really want you burying your horse there. The remains can also contaminate ground water, and because of euthanasia drugs they can't be buried near food crops. Putting a horse down can easily cost $7000 or more. This on top of any vet treatment done to try to save the animal. It is also very difficult to rehome a very old or sick horse. Nobody wants someone else's problem. Rescues often won't take old or chronically sick animals. Many end up in slaughter auctions, sold and then shipped often thousands of miles to places that process pet food, left to stand sick and alone in pens surrounded by death until it's their turn.
My old mare was an Amish buggy horse. They use their animals the way most people use cars. Once the animal can no longer earn it's keep, they get rid of it. After years of being driven on concrete roads, my mare now has severe arthritis in both knees. She is now starting to be in pain more days than not. Do I put her through another harsh winter? What if she falls in the pasture and can't get up? How long might she have to lay on frozen ground before she's found? After 15 years of love and companionship, do I really just make her someone else's responsibility? And while it's true that you can almost always find someone to take a free horse, that comes with its own dangers. 5 years ago a vet student in the southern US was charged with taking over 200 horses that were "free to good homes" and selling them at slaughter auctions (often on the same day!). The horses were then shipped to Mexico where they all were killed. It happens more often than people think.
Finally, sanctuaries have strict guidelines about what they will accept. The animals cannot have certain diseases, such as rabies, wasting disease, encephalitis, cushings, and more. They cannot be on medications that could hurt other animals. They cannot be chemically euthanized; it would poison any animal that eats the meat. They also aren't being slaughtered en mass, ensuring that the animal is killed as quickly and humanely as possible (usually a bolt to the head). Many places will allow the owners to be there until the end, a comfort to both human and horse.
Saying goodbye is never easy, but it is inevitable. Most horses won't fit into this mold of requirements. For as big as they are, they are very vulnerable to disease and injury.
I, for one, would rather know where my old girl is going, can ensure a quick humane death, and can know that her remains are being productively used to help other animals.
