State laws vary considerably regarding aspects of this question. Generally speaking, a driver of a horse and buggy or horse-driven carriage can be charged with DUI in many states, including Pennsylvania, for instance, where horse-drawn conveyance remains common in some rural communities.
Some states include riding an animal, such as riding on horseback, while intoxicated in their DUI laws; however, many have overlooked this possibility. As an example, Michigan is quite specific and prohibits bicycling, horseback riding, buggy driving, using motorized farm machinery/equipment or boating while under the influence of alcohol. Some state laws, such as those in Kentucky, include non-motorized vehicles in their DUI statutes. Horses are naturally included in this category. By comparison, in the state of Colorado, riding horses while under the influence is only a traffic violation.
If the intoxicated horseback-riding occurs in a public place, some jurisdictions rely on public intoxication statutes for prosecution, including Tennessee. In most cases this would be a misdemeanor. While this may be less serious than a DUI / DWI charge, it can still result in fines, jail time, probation, or community service, depending on the jurisdiction in which it occurs. Local legal statutes vary a great deal in this and other regards. What’s more, depending on circumstances, animal cruelty charges may also be applicable.
The shorter answer is this: Yes, it is possible to get a DUI / DWI while riding a horse. The charge carries, with a few exceptions, just as much weight as a DUI / DWI committed in a motor vehicle, with all of the legal consequences associated with such a conviction. Even for first-time offenders, this can include time in jail, house arrest, fines and/or court-mandated counseling or rehabilitation.
If you have found yourself charged with a DUI / DWI while riding a horse, the best decision you can make is to contact a trusted attorney in your area who focuses on helping clients with DUI charges. A lawyer may help you get a plea bargain agreement for lesser charges or convince the judge to allow for less disruptive forms of punishment than time spent in jail. You could have access to alternatives that might otherwise be unavailable to you. Contacting an attorney immediately after your arrest can be of great assistance in protecting your rights, especially during the early stages of the case, and in ensuring the best possible outcome at its eventual conclusion.