When discussing specific acts such as horse fucking within the context of bestiality, it's vital to acknowledge that such acts can cause significant harm to animals. Animals like horses are large and powerful, and engaging in sexual activities with them can lead to severe injury to both the human and the animal.

: This article in PMC discusses how modern welfare laws implicitly recognize animals as having "intrinsic value," which could serve as a legal foundation for formal animal rights. The Rights of Animals - Chicago Unbound

In many jurisdictions, bestiality is illegal and considered a form of animal cruelty. Laws vary widely by country and even within regions of countries, but the underlying theme is often the protection of animals from harm.