As I mentioned before maybe it makes sense to create a function which generates such type of the argument string. And put it somewhere in vitals.inc

something like generateURL(base, args); where args could be a dictionary. So that given the parameters you generate something like
base?arg1=value1&arg2=value2&....

For this particular case it would be
$owner_arg_prefix = generateURL(null, array("ot" => $owner_type, "oit" => $owner_id));