Animal rescue workers are in the process of seizing dozens of cats from an apartment in the Plateau neighbourhood.

Workers tasked with going in the apartment near Papineau and Mount Royal avenues and removing the animals called it a sad situation and one of the worst they'd ever seen.

The tenant in the apartment had lived there for about a decade but had recently suffered health problems.

The building's owner wanted to get in to do renovations and that's when the extent of the animal problem was discovered.

The owner called in animal welfare officials, who seized more than 50 cats from the unit.

Workers said the smell from the unit was overwhelming and when they moved the furniture they found animals hidden in the back of the sofa.

The cats will be transferred to the SPCA where they will be evaluated and, if deemed healthy, put up for adoption.

The tenant wasn't at the scene Thursday. The building's owner said she has been moved to a convalescent care facility.