Questions regarding toronto house rental

My fiance and I will be looking to rent a house in toronto in the next few months and I have a few questions which I have been unable to answer via research of my own so far so if anyone can clear any of the below up it would be appreciated.

1/ We have two large dogs that we will be bringing over at some stage after us. I have been able to find nice houses with an appropriate sized garden for them in my searches but have yet to see one with a fence(or at least one high enough to contain them). Is it unusual for gardens to be fenced off in Toronto in this way? How hard is it going to be to find something with a decent sized garden which is fenced off like this?
2/ Are house owners likely to be willing to negotiate over something like the above. In other words if we were to pay to have a fence put in or offer to pay extra monthly rent if they put a fence in would they likely be open to this or is this going to be difficult as well?
3/ How long typically does it take from agreeing to rent a house and being able to move in? We need to plan the optimal date for the dogs to come over, on the one hand we don't want to leave them behind for too long but on the other they obviously can't arrive until the house is ready and waiting for them. How long do you think we would need to be sure that there will be a house waiting when they come over?