ROCK COUNTY, Wis. (CBS 58) -- A Rock County teenager is accused of spiking his stepdad's drinks with cow tranquilizer.

Deputies say Tyler Rabenhorst-Malone stole the sedative from his family's barn.

The stepdad started experiencing strange symptoms.

He became suspicious of Tyler and gave an opened drink to police.

Investigators found the sedative mixed into it.

Tyler was brought in for questioning and he told police that it was meant to be a joke.