The biggest cost landlords face are all involved when a tenant moves out.
People with pets have long been demonised as undesirable tenants who leave mess and cause a nuisance to neighbours.
However, anecdotal evidence would suggest people with pets move less often, don't gripe about rent rises and take out insurance to cover pet damage.
The 'young professionals' that agents desire are by nature free, footloose and just move around more often. They certainly don't indemnify the landlord against damage; everyone now knows about the last month ditch and run tactic (avoid paying the last month's rent, deposit just about covers that, leaving agent/landlord with little money to claim damages against).
Dogs Trust has been running a 'Lets with Pets' campaign (http://letswithpets.org.uk) encouraging agents and landlords who don't prejudice against pets to highlight they are pet friendly.
However, there are still very few agents, including those on the Pets with lets directory, who advise landlords to take pets. It seems easier to just say no.
Read about the new Lonres pet search here: