The humanization of pets trend is one to watch, according to TheStreet's Jim Cramer, reflecting on this weekend's success of The Secret Life of Pets at the box office.

The Universal Studios film raked in more than $100 million this weekend, unseating Disney's (DIS) - Get ReportFinding Dory from the top spot at the theaters Friday through Sunday. (The animated fish tale dropped to third behind The Legend of Tarzan.) Cramer sees the success of The Secret Life of Pets as part of increased attention to furry friends among Americans and credited TheStreet intern Buster Coen for predicting the film's strong returns.

"No kidding, this is the humanization of pets theory that we are doing a monster good job on at TheStreet," Cramer said from the New York Stock Exchange on Monday morning. "Thank you, Buster Coen, for predicting exactly what would happen, once again, in the box office. C-O-E-N, if you want to follow him, it is incredible. He nailed this one again. He's nailed every single week."

Cramer also credited Coen for keeping an eye on a growing trend among American consumers in paying attention to and buying products for their pets. For example, last week he looked into the premium pet food market.

"[The humanization of pets] is one of the single best secular trends out there, which is the pet sleeping with you, feeding the pet food that you would, natural and organic, the idea that you take care of your pet," Cramer said. "I've been looking at Idexx (IDXX) - Get Report because of that. Obviously, any of the pure plays. Don't forget Smucker's (SJM) - Get Report , also part of this. We've had many, many articles and will do many articles, which means send your pet pictures in about what they're eating and where they're sleeping."

Looks like pets may be the investing theme of the summer.