$query = 
	"SELECT * FROM `pets` WHERE `owner`='" . 
	$_POST['ownername'] . 
	"' AND species='" . 
	$_POST['species'] . "'";

$query = 
	sprintf("SELECT * FROM `pets` WHERE `owner`='%s' AND `species`='%s'", 
	$_POST['ownername'], 
	$_POST['species']);