A 17-year-old faces felony charges after being accused of spiking his stepfather’s drinks with cow sedative.

A criminal complaint filed in Rock County Court on Thursday says the stepfather is a Rock County dairy farmer who reported the drugs were missing from the barn in January 2018 and then began experiencing odd symptoms.

The man went to University Hospital in Madison with a droopy face, slurring words, breathing heavily and stumbling, according to the complaint. Doctors told him the problem could be stress, lack of sleep and consumption of energy drinks.

The symptoms went away but reappeared in April, so the man reduced his consumption of energy drinks, according to the complaint.

Around the same time, the man found himself waking up with blankets piled on his head and would feel someone flicking his feet, and when he woke up, he saw his stepson walking away, according to the complaint.

He began to suspect his stepson was “messing with him” and causing the symptoms, and he stopped leaving his energy drinks unattended, according to the complaint. The symptoms disappeared.

The man suspected his energy drinks were being tampered with and turned over samples to the Rock County Sheriff’s Office, according to the complaint.

The man also found syringes and an empty pill bottle in the barn, one of the bottles that had disappeared.

The bottle contained pills with two ingredients: Oxytocin, a hormone, and Rompun, also known as xylazine, a sedative, muscle relaxer and pain reliever. The drug was given to cows who were giving birth.

Tests showed the presence of xylazine in two energy drinks and the syringes.

The stepson admitted he was spiking the drinks when interrogated by a deputy and said he thought it would be funny and would never hurt his stepdad, according to the complaint.

Tyler S. Rabenhorst-Malone, of 800 Wisconsin Ave., Beloit, will make his initial court appearance March 18 on charges of placing foreign objects in edibles and second-degree recklessly endangering safety, online court records indicate.