I have had tenants' cats urinate on hard wood floors, as well as carpets. Hard wood floors stain and the smell soaks into the wood. I have had cats spray walls of my rental units, causing me to have to scrub them and repaint them with Kilz to get the smell out. I have also had dogs ruin carpets and chew up floor moulding and scratch up doors. In furnished units, I have had the additional expenses of cleaning up massive amounts of pet hair and replacing furniture (fully furnished units) that was ripped to shreds by a cat's nails.

I have never had that much damage from a child.

The purpose of the additional rent or pet deposit is to take care of this added wear and tear, not for the landlord to make more money. It is simply about charging for the additional risk. By the way, by having a pet on the property, the landlords insurance rate does go up in many cases… so, why should the landlord have to cover the added costs of a pet?

I see that you mentioned about renting a "flat", which indicates to me your not in the US (probably the UK?). You should check your lease. Many leases in the US specifically require the landlord's permission in order to bring a pet onto the property. I don't know if it is the same outside the US.

Again, as I mentioned in my post. I am not opposed to renting to owners with pets. But you have to realize that pets add another equation into the rental… increased potential for insurance costs, increased potential for wear and tear, and increased problems in "de-petting" the unit for the next renter who may be sensitive to cat or dog smells.

Fortunately, just as I can potentially refuse to rent to a tenant with a pet; you can choose not to rent from an owner who wants to charge you additional rent or a pet security deposit.

All I've read in this post is oh they have a cat I will institute a way of making more money out of them. The wear and tear of a property will increase! What rubbish a cat or dog will not make a differance to the property unless the owner is a slob and doesnt clean up after there animals.

You allready have sizeable deposits which in most cases you make damn sure you keep using any excuse to tart the place up every year or two with tennants money.

If the dog is the size of a small house in a rented flat then yes there may be issues. Yapping dogs do cause some annoyance to neighbours but this is the same in owned homes. I own a small cat who is neutered in a property with Hard wood floors. If a landlord decided to charge me additional rent for a pet I would sue. Also if I decided to get an animal whilst living in a property with no pet clause I would be perfectly entitled to do so without informing you the property is owned by the tennant during the period of lease and what the tennant does is there business aslong as it isnt ilegal or causing damage to your proeperty and even if it is you have a deposit to safe guard against any repairs.