The screen needs fixing because the tenant's dog got to it. The tenants said that the screen came off the track, so they left it to the side. The tenants told us this as they were moving out. Who is responsible for fixing this? I am not sure if this is under wear and tear. Thanks!
No, it is not normal wear and tear. You said their dog damaged it. The tenants are responsible for the damage their dog caused. In this case, the landlord will likely want to buy a new screen door and he is entitled to do that – at the tenants' expense.
If the screen doors are damaged due to the tenants dog, then the tenant is responsible for its repair or replacement
The landlord fixes the structure. Windows and glass doors and screens are part of the structure (they are not taken by the renters when they move).
If the screen door "came off the track" who made it come off the track? It didn't jump off by itself.
This applies to the above as well.