If there’s one thing a dog or cat can’t resist it’s a hunk of meat. One ill-intentioned San Franciscan is playing on our furry companions’ love for treats to do them harm.

On Sunday, San Francisco police say they found dozens of meatballs that may be laced with poison. Their suspicions stem from a similar incident last year when a number of poison-laced meatballs were left around the neighborhood.

One dog died and several more got sick after eating the mysterious meatballs left last year. The meatball that killed Dorothy Schechter’s 7-year-old dachsund Oskar was laced with Strychnine.

Strychnine is a common pest poison, mostly for rats. It can kill humans by stopping a chemical that controls nerve signals. Symptoms are both mental and physical, they include muscle spasms, agitation and in more severe cases, respiratory failure and brain death.

Schechter said her dog pulled out another one of the meatballs on Sunday and she immediately knew that it was the same situation as last year.

No one was caught for those poisonings, nor are there any leads as to why the perpetrator is intent on harming the neighborhood animals.

Acting San Francisco Police Lt. Denise BonGiovanni reported 34 meatballs were left in places easily found by dogs and cats, but hidden from the eyes of owners.

“The majority of the meatballs we’ve been locating are pretty well concealed under shrubbery very close to the curbside,” said Lt. BonGiovanni, “so the dogs would most likely notice them first and have access to them first before the owners would ever see it.”

Three dogs have been reported sick near where last year’s poisoning took place. Animal Care and Control officials have posted more than 50 warning signs around the area.

San Franscisco Police are urging anyone with information to contact the department’s anonymous tip line, (415) 575-4444.