This duty in modern times requires that the owner of livestock exercise ordinary care not to let his livestock stray out onto a much-traveled highway, because under our modern traffic conditions he can reasonably anticipate that,if the livestock stray onto such a highway, they are apt to damage persons or property. Even in the absence of a fencing statute, the owner or user of land upon which domestic animals, such as horses and cattle, are permitted to roam has an obligation to fence the land in such a way as to prevent the animals from trespassing onto neighboring lands or getting onto highways. Once an adequate fence is installed, the land owner or user has the obligation to maintain it. Fences also come indifferent heights, beginning at about four feet high and going to over six feet in some instances. What is required to make the fence adequate depends upon the horses confined behind it,the proximity of the paddock or pasture to the highway, and the nature of the highway.
Statutes sometime specify fence heights.
Four feet to four and one-half feet are typical minimum fence heights for horses. Failure to construct and maintain a fence that meets state height requirements may mean that the owner or caretaker of a horse is automatically negligent if a horse jumps the fence and collides with a motor vehicle. There is also a duty to maintain the fence by replacing broken or missing boards or wires. In addition, there must be regular inspection offences to determine whether they need repair. If the fence is electric, the charge and the integrity of the wires must be checked regularly.