It can be difficult enough in this real estate market to sell a property, but when the odors of cat urine and feces are added to the mix, a sale is an even trickier to come by.

Such is the complaint that Johanna Torres and Matthew Greenberg, a Chicago couple, have lodged against the woman who lives one floor below their condo in the Commodore Green Briar Landmark building in Chicago's East Lakeview neighborhood, according to the Chicago Sun-Times.

According to a lawsuit Torres and Greenberg filed in Cook County Circuit Court Monday, the scent of the 20 cats their downstairs neighbor Rosanna Ioppolo keeps in her one-bedroom condo has permeated their apartment, caused thousands of dollars of damage to their property, triggered Torres' cat allergies and made it "impossible" for them to sell the unit, the Chicago Tribune reports.

Torres and Greenberg's lawsuit also names the building's condo association and its board members among those who did not take action after being alerted to the couple's complaints about the noxious fumes, according to the Tribune.

Ioppolo has lived in the condo below the couple for about five years, according to NBC Chicago.

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