discrimination?

My boyfriend and I were looking Monday at a townhome to rent. We have 2 cats and the landlord was amenable to allowing our 2 cats. We liked the place and gave reference names and numbers on the spot. She called us yesterday to say we were approved. My boyfriend asked her about allowing a dog b/c we have been considering getting a dog, but do not currently own one. She said 'no'. My boyfriend asked to have a day to consider whether we were still interested in renting this particular townhome. We decided that we did indeed want to rent this townhome & that we could wait to have a dog. Understand that at no time did we ever consider living there AND having a dog against her wishes, nor did we give her any sort of impression that we would do this. However, today, when we called to set up a time and place to give our deposit and sign the lease, her husband told my boyfriend that she wasn't sure she still wanted to rent to us.

Is this discrimination b/c one day we want a dog?!

It seems odd but is not illegal...she does not have to rent to you...just as you can still choose not to rent. Neither of you have any binding agreement at this point.