Chuck, Bing and Theresa Simard’s pittie mix is generally well trained, but Sunday morning — as it sometimes happens with strong, excited dogs — the urge to “dog” simply can’t be contained.

That’s precisely what happened as mom, daughter and dog walked along the shore of the American River on Sunday morning. Chuck was cool as a cuke; then he spotted some ducks.

“It happened pretty quick. I didn’t realize he was going to go for it,” Theresa Simard told Fox40

Bing tried to prevent it to no avail.

“I could not hold it anymore, and he just ran through the water to get the duck,” Bing Simard said.

Once in the water, Chuck seemed to have things under control at first, but then the current kicked in. Bing watched the companion who has been by her side since her husband died drift down river.

“You know, your heart is pounding because you can see him fading away from you,” Bing Simard said.

“I started screaming, ‘can anybody help?’” she said.

And someone did: an unidentified man who had been walking two pit bulls of his own.

“I think what he did was ran parallel in the water and jumped in the water, and dragged all 70 pounds of Chuck to shore. It’s pretty incredible,” Theresa Simard said.

The Simards got his name — Stephen — and snapped a picture, but they were too overwhelmed to do much else.