There are few towns more dog-friendly than Portland: 40 percent of residents here own a pooch or two.
"I never met anyone who didn't like dogs," says one resident.
But, as CBS News Correspondent Jerry Bowen reports, somebody doesn't. The city's tranquil Laurelhurst Park, a favorite of owners and their pets, has become a killing ground.
"It's incredibly upsetting and demoralizing," says veterinarian Erika Zsomber-Murray.
She treated most of the 11 dogs that have died, and the eight that were sickened: all poisoned by sausages laced with weed killer left in the park.
Sara Roberts' dog Taro was one of those that died.
"I never in a million years would have thought my dog would be a victim of it," she says.
Dog owners' fears have gone city-wide since the poisoning started the 4th of July holiday weekend. But the motive may be tied to an action taken a month earlier: a controversial city crackdown on free running dogs. When dog owners started protesting the leash law, the dogs started dying.
"She's not a troublemaker," says one dog owner of her pet. "But there are others who are, I suppose."
In fact, free running dogs are one of the most frequent complaints called into police across the nation. With unleashed dogs, a major cause of the nearly 5 million dog bites in the country each year.
And the majority of the victims are children, like a 4-year-old, whose mother asked not to be identified. Her child was attacked this year in a Portland park by an unleashed Rottweiler which ripped the child's jeans and bruised her leg.
"She's had a lot of psychological trauma," says the mother. "She's afraid of dogs and you can't blame her."
The mother reported the attack to a Web site that many dog owners blame for inciting the poisonings. The Web site operator denies any involvement, and dog owners are pressing police to solve the case, staging a "take back the park" rally and raising a reward fund far larger than anything offered in human cases.
"If we could get a reward fund of $15,000 for any of our homicides we'd be ecstatic, but unfortunately they just don't draw that much attention," says police Sgt. Brian Schmautzer.
But the mystery killer has Portland's attention now, a city where a walk in the park doesn't mean what it used to.
"I'm a little bit nervous about the dog poisonings," says Becky Marquez. "It's just like murdering our children."