REUTERS/Sergei Karpukhin
A dog catches a Frisbee during a dog frisbee competition in Moscow, September 13, 2015.
According to statistics provided by lettings specialist E J Harris, a three-bedroom London flat costing £2,500 per week would generally demand a deposit of about £15,000.
However, if a tenant has a dog, they could expect that deposit to increase to £25,000, a two-thirds rise.
On top of this extra cost, many landlords will also include a clause in tenancy agreements that forces tenants to pay for professional cleaning services at the end of their lease. These services can cost hundreds of pounds.
As with the rest of the UK, dog ownership in London has grown in the past decade, and 8% of Londoners now have at least one dog.
In 2014, the UK Pet Food Manufacturer's Association found that dog ownership in the UK is growing, and that in the last 15 years, pet ownership has grown by more than 4 million. Now, some 24% of all UK households own one or more dogs.
The problem of dog owners being charged higher deposits is being fuelled in large part by the fact that more than 40% of all 'prime' properties in Central London do not allow dogs, thanks to stipulations in the head lease of the building.
Things are so bad that almost half the time prospective tenants will not disclose that they own a dog until they have made an offer on a flat, and it can now take up to seven times longer for a dog owner to rent a flat than someone without any pets.
Big extra costs may be involved in owning a dog in central London, but it clearly isn't putting people off bringing their four-legged friends into the capital, and demand is still growing.
Within the capital, properties near to Hyde Park, Regents Park, Green Park, and Holland Park - where dog owners can walk their beloved pooches - are proving the most popular with renters which in turn is further pushing up prices in these areas.
Elizabeth Harris, managing director of E J Harris, said: "Despite the stigma surrounding tenancies with pets, in our experience tenants who own dogs make for reliable and responsible tenants who take good care of the property and keep their pets pampered and well trained."