For most Americans, pets are like family.
The rate at which U.S. consumers open their wallet to feed their furry companions has become big business: Pet food alone is now an industry worth more than $26 billion and growing, according to IBIS World figures.
That has led some experts to question the regulations that safeguard the industry—and ingredients being used.
"No one's really minding that store right now… It's left up to the consumer to know that it's safe," said Joseph J. Wakshlag, a veterinarian specializing in nutrition at Cornell University, told CNBC's "On the Money" in an interview.
In the past 2 months, two brands of canned dog food, Evanger's Dog and Cat Food, and Cocolicious, made by Party Animal, were found to contain a drug called pentobarbital that's used to euthanize animals. One dog died, while others were sickened.
Evanger's is now suing a supplier, saying the meat which was labeled, "inedible hand boned beef," actually contained pentobarbital-tainted horse meat.
"Evanger's will never purchase from this beef supplier ever again. We immediately initiated even more new testing methods and are testing every single beef product before being shipped.," said Holly Sher, Evanger's owner and president, in a statement e-mailed to CNBC.
In a statement posted on their website, Party Animal said, "The safety of pets is and always will be our first priority. We sincerely regret the reports of the discomfort experienced by the pet who consumed this food….Party Animal wishes to emphasize that we have submitted many recent lots of our beef flavors for testing and all have tested negative for any pentobarbital."