Doggie Fountain of Youth?

For many of us, Fido, Buttons, or Puck are beloved members of the family and we spare no expense (within reason) when it comes to ensuring their comfort and health.  In fact, according to the American Pet Products Association, Americans spent nearly $51 billion in 2011 on their furry and feathered (or gilled) companions.  Not everyone can treat their pets to a $3.2 million diamond studded dog collar, but you might be swayed by the following Purina dog food commercial, which claims to extend your four-legged friend’s life by 1.8 healthy years:

According to the ad, “YOU have the power to help significantly extend his healthy years,” a statement that is apparently based on a “groundbreaking 14-year study by Purina.”  The commercial says that the study “proves that Puppy Chow, then Dog Chow Nutrition, fed properly over a lifetime can help extend his lovable antics up to 1.8 healthy years.  Long live your buddy, long live your dog.  Purina Puppy Chow and Purina Dog Chow.”

Who could argue with such compelling evidence?  But before you rush out to your local pet store to stock up on Purina dog food, you might want to get a bit more clarification.

TINA.org’s Investigation

TINA.org enlisted the help of Robi Totkin, owner of a local obedience training and pet supply store, to get the scoop.  Robi called Purina directly and asked for a copy of the referenced “groundbreaking study.”  In response, Purina sent Robi a nice, glossy brochure featuring a picture of a fat Labrador Retriever eating out of a bowl labeled “Chubby.”  Not exactly the professional research paper Robi was expecting.

Robi dug deeper and was able to locate the Purina study in the Journal of American Veterinary Medicine Association.  Here are just a few things that the TV commercial left out:

• The study used only 48 dogs (not a statistically large sample), all of which were Labrador Retrievers, despite the commercial’s implication that the results generalize to all breeds.

• The study doesn’t specify what type of food was fed to these dogs.  We don’t even know if the dogs were given Purina brand food.

• Tellingly, the title of the study is “Effects of diet restriction on life span and age-related changes in dogs.”  In other words, even though the commercial implies that feeding Purina to your dog will help him live a longer life, the real conclusion of the study is that “lean fed” dogs live longer than their all-you-can-eat-buffet fed counterparts.  Did we really need a study to tell us that?

• If we paid attention to the fine print in the commercial, we would have noticed this flash across the screen: “Feed to ideal body condition.  Follow feeding instructions on the bag.”  How are we supposed to know our dog’s ideal body condition?  Is that even possible?  Compare this to a statement in the study’s conclusion: “The actual caloric intake needed to achieve a desired extension of life span and improved health varies among individual dogs because of high intrinsic variation in caloric requirements both within breeds and within the species as a whole.”

Our Conclusions

So what are we left with?  A study that says that food-restricted Labs in this particular study live longer.

A more realistic version of the commercial might go like this:

“Your Labrador retriever is one of a kind.  If you have some other type of dog, this information may or may not be useful to you.  The people at Purina decided to do a study.  These nice scientists employed by the company whose commercial you are watching found that dogs who eat less are leaner and healthier and therefore live longer than their chubby pals.  Long live your dog, long live our profit margin.  Purina Puppy Chow and Purina Dog Chow.”