Authorities are warning that an opiate used by veterinarians for elephants and other large animals is circulating among heroin users in Ohio.

The synthetic opioid carfentanil is 100 times stronger than fentanyl, the analgesic blamed for increasing overdose deaths, and it's 10,000 times stronger than the morphine on the streets.

The Hamilton County Heroin Coalition warned this week that the powerful opiate has been identified in supplies of heroin in the Cincinnati area. It's also being blamed for a recent spate of overdoses in Akron and Columbus.

Akron Police Lt. Rick Edwards says there have been 91 overdoses and eight deaths in the city from July 5 through early Thursday.

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According to The Cincinnati Enquirer, Akron police reported 25 overdoses, four of which were fatal, in a recent three-day period, while Columbus reported 10 overdoses in a nine-hour period, two of which were fatal.