In the latest in a string of debt-related lawsuits to hit the Thoroughbred business, PNC Bank has sued Buck Pond Farm and McKathan Brothers Farm in a Kentucky court.According to a Blood-Horse report, the bank alleges Buck Pond and the McKathans owe more than $930,000 and $499,000, respectively, on loans dating between 2007 and 2008. The loans originated with National City Bank, since acquired by PNC Bank.Buck Pond Farm is a breeding facility in Versailles, Ky., operated by Doug and Karen Arnold. McKathan Brothers Farm is a stud farm and training center located in Citra, Fla., near Ocala. Its owners are Kevin and J. B. McKathan.The bank is seeking a judgment in its favor as well as a declaration that it has enforceable liens on collateral including horses and stallion seasons and shares.