Picking
up dog poop is not just for aesthetic
purposes
Dog Waste Facts from USA
Today
06/06/2002 - Updated 09:07
PM ET
Dog waste
poses threat to water
By
Traci Watson, USA TODAY
For as long as the dog has been man's best friend, dog
waste has posed a menace to man's nose and foot. Now science
has revealed a more unsavory truth: It's an environmental
pollutant.
In the mid-1990s, scientists perfected methods for
tracking the origin of nasty bacteria in streams and seawater.
From Clearwater, Fla., to Arlington, Va., to Boise the trail
has led straight to the hunched-up dog — and to owners who
don't pick up after their pets.
At some beaches, dogs help raise bacteria levels so
high that visitors must stay out of the water. Goaded by such
studies, some cities have directed as much as $10,000 in the
last few years to encourage dog owners to clean up after their
pets. A few municipalities have started issuing citations to
those who ignore pet clean-up ordinances.
Many dog lovers are in denial about their pooches'
leavings. But researchers have named the idea that areas used
by dogs pump more bacteria into waterways — the "Fido
hypothesis."
Dogs are only one of many fixtures of suburban America
that add to water pollution. Lawn fertilizers, rinse water
from driveways and motor oil commonly end up in streams and
lakes.
But unlike those sources, dogs generate disease-causing
bacteria that can make people sick. Studies done in the last
few years put dogs third or fourth on the list of contributors
to bacteria in contaminated waters. "Dogs are one of our usual
suspects," says Valerie Harwood, a microbiologist at the
University of South Florida. "At certain sites, we find their
effect to be significant."
It doesn't take a Ph.D. to figure out that dog do is
nasty. But it took science to determine how nasty it
is.
From mutt to blue-blooded champion, all dogs harbor
so-called coliform bacteria, which live in the gut. The group
includes E. coli, a bacterium that can cause disease, and
fecal coliform bacteria, which spread through feces. Dogs also
carry salmonella and giardia. Environmental officials use
measurements of some of these bacteria as barometers of how
much fecal matter has contaminated a body of water.
This wouldn't matter if pet dogs were as rare as pet
chinchillas. But four in 10 U.S. households include at least
one dog, according to the American Pet Products Manufacturers
Association. The association's statistics also show that
Americans owned 54.6 million dogs in 1996 and 68 million dogs
in 2000. Of that total, 45% were "large" dogs — 40 pounds or
more.
Those numbers add up to a lot of kibble. That wouldn't
matter if all dog owners also owned a pooper-scooper. But
several studies have found that roughly 40% of Americans don't
pick up their dogs' feces (women are more likely to do so than
men).
New analysis provides answers
The environmental impact of dog waste went unrecognized
for decades. Then scientists developed lab techniques to
determine the origin of fecal bacteria contaminating water.
One method is a variant of DNA fingerprinting. Another method
looks at the antibiotic resistance of microbes from different
species.
Scientists caution that the methods are still new. They
are able to distinguish between major and minor sources of
pollution, but they can't say with precision whether dogs
contribute 20% or 30% of the pollution in a stream. "There's
inherently some error," says Don Stoeckel, a microbiologist
for the Ohio district of the U.S. Geological Survey who's
studying bacteria-tracking methods. "I think the best (they)
can do is give you some evidence of the magnitude of each
source."
Nonetheless, Stoeckel says, the analytical tools do
provide useful information. Researchers have studied dozens of
waterways. Wild birds and humans usually head the roster of
who's fouling the water. But in some areas, dogs make
significant deposits.
At Morro Bay, Calif., for example, dogs contribute
roughly 10% of the E. coli, says Christopher Kitts, a
microbiologist at California Polytechnic State University-San
Luis Obispo. "And that can be the difference between a beach
closing and a beach not closing," he says.
Places where dogs dirty the water:
- Stevenson Creek in Clearwater, Fla. Residents
were worried that a sewage treatment plant contaminated the
creek. But when Harwood tested the water, she found that
dogs, along with leaky septic tanks and wild animals, were
to blame for high bacteria counts. Dog feces probably washed
out of yards by the creek, Harwood says.
- Four Mile Run in Arlington and Fairfax counties,
Va. Studies show that dogs add to the contamination in
this suburban Washington, D.C. stream. Officials calculate
that the 12,000 dogs living in Four Mile Run's watershed
leave behind more than 5,000 pounds of "solid waste" every
day.
- Boise River in Boise. The river suffers from high
bacteria levels that make it unsuitable for swimming.
Testing of streams and drainpipes flowing into the river
showed that in urban areas, dogs were a leading culprit. In
some spots, dogs and cats account for even more of the
bacteria than human feces — from dysfunctional septic tanks
and leaky sewage pipes — do.
Fines don't sway some
Even where dogs aren't the prime offenders, they're one
of the few polluters authorities have control over. At many
California beaches, for example, seagulls and other birds are
most responsible for high bacteria levels. But federal laws
protect birds.
That leaves dogs. Officials know that they have a lot
of educating to do before people realize their pooch can be a
canine sewage pipe. Some people find it humiliating to carry a
plastic bag.
A survey by the Center for Watershed Protection in 1999
found that of the 41% of respondents who rarely or never clean
up after their dogs, 44% would refuse to do so in the face of
fines and neighbors' complaints. Reasons included, "because it
eventually goes away," "small dog, small waste," and "just
because."
So more cities may follow the lead of Laguna Beach,
Calif., a wealthy beach enclave. The city provides
pooper-scoopers at the local dog park. But many people "don't
take care of their little friends," says Victor Hillstead, the
city's parks and buildings manager.
So the city hired Entre-Manure, poop-scooping service
based in nearby Dana Point whose motto is "#1 in the #2
Business." Since the city's contract started in January, the
service has collected 187 pounds of dog waste from the city.
"I'm real proud of that fact," says Craig Stern, founder and
chief picker-upper. "That's pollution that'll never reach the
ocean."
