W. Va. Code § 19-17-10
When each of the adjoining owners of a partition fence has been allotted a particular part thereof to maintain, and either owner fails or refuses to keep in good repair the part of such fence so allotted to him, he shall be liable in damages to the adjoining owner for all damages occasioned by animals kept by him trespassing on such adjoining premises as the result of such failure or refusal to repair. The adjoining owner may serve written notice on the owner whose duty it is to keep his part of such fence in repair, requiring him to repair the same, and if such owner fails or refuses so to do within ten days after the service of such notice, the adjoining owner may repair such part of the fence, and the owner whose duty it is to keep the same in repair shall be liable to him for all the expenses of such repair.
W. Va. Code § 19-17-10