We've always had 2 dogs & just never bothered telling them either

All of the houses we've lived in have been newish & in nice areas so the chances of us being allowed to have one dog let alone 2 was slim (Big dogs as well)

We only ever told them about the dog for the house we were in previous to this one because there were no side fences & we wanted to put them up (for the dogs & also for Luke & the privacy)
They were hesitant until I suggested paying an extra weeks worth of rent with the bond (as a dog bond) - and did the same as Christy & had a reference.
I still only told them about the one dog though (and he was the old one that slept all day on the back step).... didn't bother telling about Leo the naughty boy

For this house &the next one we just haven't bothered... Like Jen, the houses are always cleaner when we leave them compared to when we entered them

Leash, my girlfriend & I did that with her cat when we first rented as well!!!