What to do if the bank rented property to people with aggressive dog breeds that are prohibited by the HOA?

If you have told the management company about this but they have not taken any action to resolve the problem, you should bring it to the attention of the the board of directors.  It often helps to get other unit owners involved.  It may be helpful to circulate a petition requesting that the board take action to require that this be removed from the premises.  If you show the board that a large number of owners are concerned about this situation, they will be encouraged to act.  You should write a letter to the board describing the problem and in the letter point out that this situation could potentially cause legal liability to the unit owner's association if the dog injures an owner, guest, mail carrier or someone else on the premises.  You might also ask the board to check with association's liability insurer to ask about the potential liability that this situation could casue to the association and the board in the event that someone is injured by the dog.  You should also send the management company a copy of any letter that you send to the board.  The board can put the unit owner and tenant on notice that keeping this dog on the premises is a violation of the association's rules, regulations, bylaws, etc.  And they should impose fines against the unit owner and tenant as authorized by the condo documents.  The best way to solve this type of problem is usually to convince the members of the board that many unit owners are concerned about the situation; and that the association is at risk of liability if the problem does not get resolved.