Police allege Walter William Wolford Sr, 66, of Hagerstown, Pennsylvania, caused his wife Catherine's head to snap back and left red marks around her neck after tugging at the red nylon leash when she walked too far away.
But Wolford told police the woman had late-stage dementia and had wandered off before when officers confronted him on Saturday, the York Daily Record reported.
He also claimed the eight-foot leash was initially secured around her waist but had moved up over the course of the day.
'Walter told me he originally placed the leash around her waist, but somehow it had moved up around her neck and when she walked away from him and all of the slack became taut, he "gently tugged on the leash so she would stop",' charging documents say.
But a witness claimed to police Wolford had 'yanked' the leash, causing Catherine to be pulled back and to sustain red marks on her neck.