Moncton, New Brunswick’s fire department responded to 52 overdose calls over the weekend, a huge jump from its usual four or five per day.

Harm reduction organization Ensemble Moncton suspects a tranquillizer called medetomidine-a powerful sedative not intended for human use-may be in the local drug supply.

Fire Chief Conrad Landry called it one of the worst stretches he has seen in eight years. By Monday, calls had slowed, leading him to hope it was just a "bad batch."

Josue Goguen, a front-line supervisor at Ensemble Moncton, says they handled 25 overdoses on Friday alone, one of their worst days ever. New Brunswick’s health department is monitoring the situation, while Nova Scotia Health has already warned of high-toxicity fentanyl in neighboring Cumberland County.

Landry noted the fire department was stretched thin, with crews sometimes waiting 20 to 30 minutes for an ambulance. Starting in July, a dedicated medical response truck will be added to help alleviate the strain.