Issues about filling loss in tax

[Mahsa Nicknam]

I've recently heard that if an investor files loss in his investment property in filling his tax, it will effect his next mortgage by impacting on debt/income ratio. 

For example: If you earn $10000 from your rental property and in your tax you show that you had $15000 expense (= $5000 loss), the next time you are applying for a mortgage for another property, $5000 will go toward your expenses (5000/12 for each month) and it will impact your debt/income ratio.

Does anyone have an insight about this? Is this a true statement. 

Thank you all in advance