Two dog were seized by convulsions and died after eating poisoned dumplings while being walked in Tokyo’s Nakano Ward in February, police said Saturday.
Strychnine nitrate, a toxic chemical used to destroy animals, was found in the stomach of one of the dogs killed on the morning of Feb. 19.
The same chemical was found in six Chinese dumplings found on Feb. 26 and March 9 under a utility pole near the place where the two dogs died.
Police are investigating the case as a possible violation of the Poisonous and Deleterious Substances Control Law and are distributing pamphlets to warn residents.
Strychnine is specified as a poison under the law.
Although used by veterinarians to resuscitate animals whose heart and breathing have stopped, an overdose causes violent seizures and death. It was once used commonly to put animals to death.
The drug is transparent and odorless, and stimulates the central nerve system, causing a convulsion of muscles and breathing difficulties.
The drug was linked to the murders of several dog owners in 1993 by a dog breeder in Urawa, Saitama Prefecture. According to experts, a 5 mg to 30 mg dose of the drug would be fatal to dogs while a 50 to 100 mg dose would be fatal to humans.