NEW YORK (CBSNewYork) – In less than one week, as many as 100 pigeons have died on the Upper West Side and officials say others pets could be at risk.

1010 WINS’ Terry Sheridan reports

Karen Heidgerd, administrator at Animal General, is convinced the birds were killed by someone using Avitrol, which was banned in New York City in 2000.

“We started seeing birds in full seizure activity,” Heidgerd told 1010 WINS’ Terry Sheridan. “People reported that the just fell out of the sky.”

Avitrol is marketed as a repellent and is added to kernels of corn. When the birds ingest the kernels, they have seizures almost immediately. They are dead usually within an hour, Heidgerd said.

Heidgerd said she believes someone planted the banned substance on a residential block and fears dogs and cats will eat the tainted corn too.

“It will affect them the same way if they ingest a lethal dose,” Heidgerd told CBS 2’s Dave Carlin. “Small dogs don’t need much to get the lethal dose.”

Some area residents voiced their opinions about the pigeon poisonings.

“I don’t like pigeons. They’re annoying and they are messy, but I wouldn’t want to poison them,” said Katie Paladino.

“I don’t like them but I don’t think they should be poisoned,” Queens resident Sophia Panapitopolous said.

There are humane ways to control pigeons including netting, wires and spikes to keep them from nesting.

CBS 2 reached out to the makers of Avitrol, based in Tulsa, OK, to ask about the safety of its product. So far there has been no response.