We have a limit here -- I am pretty sure it affects most of the province. Only two dogs per household unless you have a kennel license which requires more than an acre of land, and it costs I believe something around $120 a year (not including licensing your own dogs). This is one reason I don't license my dogs. They don't know how many I have, and unless I get a complaint, they never will (or atleast they won't care). They are pretty lenient when they see households with more than two dogs -- it's just the ones the recieve complaints that they enforce the rule for.
Another thing -- it isn't just ownership. It's PER PROPERTY -- meaning I am not allowed to have more than two dogs on my property at any given time. Because I own a grooming business, I often have many dogs on my property at once. But again, unless you get a complaint it's not something that is really enforced. I'm sure it's that ay in most places too (atleast one would hope!).

MOST places have a limit.. You just don't hear about it when you don't recieve any complaints. Everyoen should keep it that way! Let's keep our dogs onleash, in our yard, and quiet.