Negotiations ... in the rental market?

First - does anyone remember when the rental rates became negotiable?  When I rented I never considered rentals rate to be negotiable - if you wanted a small rental amount ... you rented a smaller place!

So I run several ads for my rental properties and every once in a while I come across one that I just can't believe my eyes (email is a wonderful thing ... when not inundated) and I seemed to have truly offended someone and I actually had to go into my sent folder to see if maybe in my tired state I offended my email client somehow.

I had to get a second opinion - this client asked (as many do) if the landlord would be willing to accept pets - some landlords will not since pets have had a bad history to have their owners leave a mess behind of some kind of damage, or neighborhoods have restrictions on size and breeds.  I sent the client back an email stating that Yes, the landlord would allow a pet on the premises, but with a non-refundable pet fee, and we would need to know the breed, weight, and up to date shot records before making the final approval for the pet application. 

The response that shocked me .... the client stated that his pets were his children and how dare I ask that their records are up to date - he no longer wanted to rent my rental and was disgusted by my question - I don't ask the same for children do I?

Well at that point I had to email back - I stated on how its a standard question we ask all potential clients and especially in my profession I have seen horrible things - pets, children, adults from abuse to negligence. (as for children ... shot records - they have to have blue and yellow cards to even be allowed to register for school! ... and they do bite too!)

Since I no longer felt comfortable I sent the email and its stream of history for my office manager to handle (they have that special calming touch) since he no longer wanted to deal with my hoping that maybe she could explain in her magical way that's its a normal question.

All in all ... the client apologized to the office manager stating that she had rescued one of her "children" from an abusive relationship and my so called absurd question set off an anger trigger. hummmm what a situation it was indeed.

So here is my question ... is there another appropriate way to ask about potential clients other family members?

Thanks ... I just had to share this one!