Tenant fined £1,000 for moving into a rental property with pets when signing a 'No Pets' clause. £12,000 worth of damage was caused and the former tenant was only asked to pay a vey small amount back. This has been described as a very unusual case... follow the link for more info. 

http://www.propertyindustryeye.com/tenant-who-signed-no-pets-clause-ordered-to-pay-1000-after-moving-in-with-dog-and-cats/