It’s not uncommon for companies to point the finger at the test when they receive bad marks, said Scott Stanley, an associate professor at the University of California-Davis’ School of Medicine and Animal Health and Food Safety Laboratory System.

“From the standpoint of a person who’s been running a lab for a lot of years now, I’d say it’s typical for people to criticize the testing,” Stanley added. “But if you have a lab test multiple products and some turn out fine, it’s unlikely to be a problem with the analytical test. Besides, they used a very effective means of verification by sending the samples to a second lab.”

Also reviewed were two pet supplements:

• Joint MAX Regular Strength, Now with Manganese, made by Pet Health Solutions, contained just 2.1 percent of the chondroitin advertised on its label, but did contain the proper amount of glucosamine.
• Nutri-Vet Nutritionals Hip & Joint Soft Chews was found to be lacking in both ingredients with 47.2 percent of the advertised glucosamine and 0.7 percent of the chondroitin.

Nutri-Vet’s vice president for research and development, Phil Brown, said he was surprised by the results. “We test our product on a regular basis,” Brown said. “I’m not happy to hear this. We are taking this very seriously.”

After receiving calls from MSNBC.com to ask about Joint MAX, Pet Health Solutions issued a voluntary recall of the lot tested by ConsumerLab.com.

It was an older lot, said Bob Singh, president of the company. “We did a voluntary recall of the lot because of the apparent findings of ConsumerLab,” he added. “But we’re not worried about it at all.”

Singh also disputes the ConsumerLab.com findings. “Our manufacturer tested the raw materials and the result was totally consistent with what the label says,” he said.

Ultimately, it’s no surprise when products don’t include the supplements they’re supposed to contain, said Dan Hurley, author of an investigative book on the supplement industry called “Natural Causes: Death, Lies, and Politics in America's Vitamin and Herbal Supplement Industry.”

When it comes to supplements, “nobody is watching,” Hurley said. “It’s an insane situation. There are no government-mandated standards for manufacturing.”

Linda Carroll is a health and science writer living in New Jersey. Her work has appeared in The New York Times, Newsday, Health magazine and SmartMoney.

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