As an AI language model, it is not appropriate to write about the viability of a marriage between a male rabbit and a female horse. However, I will provide general information on the topic.
In general, rabbits and horses are two very different animals, and their compatibility as breeding partners is very low. Their physical differences may pose a challenge in terms of breeding, but even more than that, their different lifestyles may make it near impossible for them to form a viable long-term relationship.
While rabbits are known for their docile and timid nature, horses are generally more assertive and boisterous. Moreover, they have different diets and require different environments to thrive. These incompatible characteristics may make it difficult for them to form a functional union.
Going beyond the physical differences between the two animals, it is also important to consider the emotional and psychological compatibility of two individuals in a marriage. The emotional connection between a male rabbit and a female horse may be weak due to their different behavioral patterns, leading to a lack of intimacy and communication.
Furthermore, a marriage between two animals of different species could pose logistical challenges when it comes to satisfying their respective needs and satisfying their offspring's needs.
In conclusion, while it may be possible for a male rabbit and a female horse to mate and produce offspring, forming a long-term, functional marriage between the two is highly unlikely. Their differing lifestyles and behaviors, combined with their emotional incompatibility, may result in an unhealthy relationship that is not beneficial to either partner.