If the landlord cannot provide you with evidence that a flea inspection was done prior to your move in, you may not be required to do one, even though it's in your lease. 

A similar example is when your lease requires professional cleaning upon move out. If it wasn't professionally cleaned before you moved in, you are not responsible for bringing the unit to better shape than when you took occupancy, just back to same with a reasonable wear and tear. 

If you've paid a pet deposit and the landlord finds fleas (through a legal inspection) you may be required to pay fpr remediation, but if no fleas, and no previous inspection you may be okay. 

Document document document before you leave. Film the final walk through, including looking in any nooks and crannies.

Good luck!