Saturday, May 15, 2004

San Francisco Chronicle - SFGate.com

Odor eliminators don't always pass the smell test
Some cleaners only provide brief relief

By Sophia Yin

Have you ever wondered which of the many urine and odor elimination products on the market actually erase the evidence of your dog's potty problems or successfully stifle the stench of kitty urine spray? Well, according to a 1989 study headed by Dr. Bonnie Beaver at Texas A&M University, some clearly work better than others.

Beaver and her collaborators methodically took uniform carpet squares and doused them with 8 milliliters of cat urine. Then they treated each carpet sample with a different product and compared the results to a carpet that contained urine without any cleaning treatment (positive control) and to a clean piece of carpet that had never been drenched with urine (negative control).

They put the pieces to an odor test involving two human sniffers and a third who refereed if there was a tie. Overall, they found that enzymatic products such as Cat-off, F.O.N. and Outright Pet Odor Eliminator work best. Other products such as Woolite spray foam rug cleaner work well to mask the odor. But products that were made primarily to clean carpets only got rid of odors temporarily.

Since then a number of additional products for eliminating urine odors on the carpet have been introduced onto the market, including one that sounds as if it's too good to be true. It's called Petrotech Odor Eliminator, made by SeaYu. This product "shears and encapsulates the odor source," according to the product info sheet, and is supposedly effective not only on urine, but on smells ranging from skunks and dead rodents to cigarette smoke, smelly gym shoes and the dreaded week-old trash.

Two students in my domestic animal behavior laboratory class last winter, a class in which pairs of students design and carry out their own animal behavior experiment, decided to test some samples that SeaYu had sent me. But unlike the previous study, the students, Chris and Emily, let dogs rather than people judge whether the product eliminated odors. After all, a dog's olfactory acuity is 100 to 1,000 times greater than a human's. If the potty spot smells clean to humans but smells like a toilet to Fido, then Fido might still find it the preferred place to potty.

The students first set out for the local hunting supply store, where they found a product they thought would consistently attract dogs. They would be measuring the time dogs spent smelling the stinky spot as an indicator of whether the dogs could detect the odor. The product they chose was Carlton's Calls Mule Deer Dominant Buck Urine, which, states Chris, "is the most awful smell I've ever smelled." To a female deer it smells like Chanel No. 5, and to the two dogs that got a sneak preview, it sucked them in like an olfactory undertow.

Chris and Emily carefully cut uniform pieces of rug and treated three with the stinky urine. Then they applied an enzymatic cleaner to one, Petrotech odor eliminator to the second and kept the third untreated as a positive control. They also cut a fourth carpet that never had urine scent and used this clean carpet as a negative control.

Next, they went to the dog park and spaced these rugs an equal distance apart and enlisted park visitors to let their dogs investigate. Each owner allowed the dog to sniff each carpet while Emily timed the interest. Owners did not know which carpets contained which treatment, lest their knowledge bias the results.

And the exciting results were:

No difference between treated and untreated rugs?

Yes. This may sound surprising, but it's a fact of life in behavior research that more will go wrong than right. In this case, dogs at the dog park were more interested in playing or smelling the other aromas. So Dominant Buck Urine wasn't as attractive in the midst of a pool of other perfumes. Of course, virtually all students in the lab class learned that their hours of brain strain and labor ended up in what could only serve as a pilot study rather than one that would actually work.

Study results aside, this left me back at testing the product the quick and dirty, semi-scientific way. First, I had all of the students sniff test the Petrotech-treated and untreated carpets. Most said they could smell the dominant buck odor on the carpet with Petrotech.

But maybe deer urine was just too pungent? So then I tested the Petrotech in my home. I tried it on several dog beds that were responsible for creating a barrier of stink in my bedroom, on the doggy-smelling seats of my car, in one of a pair of tennis shoes, and in a dog carrier that had housed two chickens for a day.

A small spritz on the dog beds did nothing to the odor in my room, but extremely liberal application (enough to keep the beds wet for hours), and I was finally able to walk in without tearing up from the stench. The room did smell like a mix of new car and fried doughnut, but this scent dissolved by the next day. Close inspection of the beds, however, revealed that they still smelled like dog close up.
The car fared markedly better, possibly because my dogs don't sleep in the car. The untreated and treated shoes, on the other hand, smelled the same no matter how hard I breathed in. And yet, in another twist, the carriers that had housed my chickens (and their poop) clearly smelled better. The carriers no longer stunk up my yard.

Overall, I think someone besides me or my students needs to study new products scientifically. As for the Petrotech odor eliminator, it clearly works well on some odors, possibly depending on the odor penetration, and not as well with others, although I can't say what a dog or cat would think. But at $12.95 a can, I recommend you give it a try.

For information

Petrotech odor eliminator: www.sea-yu.com or call (415) 566-9677.

Sophia Yin, DVM, is a small-animal veterinarian in Davis with an animal-behavior Web site at www.nerdbook.com/sophia. Send questions to her via her Web site or to P.O. Box 4516, Davis, CA 95616.

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