Pets can be expensive—vet bills, kibble, toys, dog treats. But many dog and cat owners may have overlooked another expense: pet rent.

At the Sovereign Park apartments near DC’s Thomas Circle, there’s a $750 one-time charge for a dog, which must weigh less than 50 pounds. Doggy rent tacks an extra $55 onto monthly bills. Cats cost an owner $500 up front plus $35 a month.

In Columbia Heights, the Park Triangle apartments have a hefty pet rent and fee as well. There are no weight restrictions, but any pet weighing more than 30 pounds costs a nonrefundable $600. Dogs this large also carry a $50 monthly charge in rent. For pets less than 30 pounds, the move-in fee is $400 plus $30 a month in pet rent. Alexandria’s Foxchase Apartments has a weight restriction of 35 pounds and charges a $300 fee with a $40 pet rent.

Other locations requiring both a pet fee and rent include the Ellington on U Street, Mass Court Apartments at Third Street and Massachusetts Avenue, Northwest, and the new Newseum Residences in Penn Quarter. All limit pets to two per apartment, carry $400 to $500 nonrefundable fees, and require $25 to $50 a month in pet rent.

Most apartment buildings also limit dog breeds. Rotweillers and Dobermans are some no-nos, but certain smaller breeds such as terriers have also made the list. Restrictions are usually based on how aggressive the dog breed is believed to be.

Southwest DC’s Waterside Apartments restrict Great Danes, St. Bernards, and German shepherds, among others. Fees per dog are $400 plus $60 per month. Cats cost a little less: $300 plus $35 a month. Upstairs at Bethesda Row allows large dogs—up to 75 pounds—but requires a vet’s signature to verify the breed. It asks for a $250 fee plus $45 a month.

The lesson: If you have a furry friend, you may want to call for weight, breed, and cost restrictions before signing on the dotted line.