Try this... first remove all of the default file names in the file uploads, so the lines:
'DefaultFileName' => "".($WADAhorses_update->getColumnVal("horse_profile_pic") ) ."",
become:
'DefaultFileName' => "",
Then update the bindings from:
$UpdateQuery->bindColumn("horse_profile_pic", "s", "https://mysupersite.com/horse-sale-2020/".$WADAhorses_update->getColumnVal("horseid") ."/".($WA_DFP_UploadStatus["WA_UploadResult1"]["serverFileName"]) ."", "WA_BLANK");
$UpdateQuery->bindColumn("horse_pic2", "s", "https://mysupersite.com/horse-sale-2020/".$WADAhorses_update->getColumnVal("horseid") ."/".($WA_DFP_UploadStatus["WA_UploadResult2"]["serverFileName"]) ."", "WA_BLANK");
$UpdateQuery->bindColumn("horse_pic3", "s", "https://mysupersite.com/horse-sale-2020/".$WADAhorses_update->getColumnVal("horseid") ."/".($WA_DFP_UploadStatus["WA_UploadResult3"]["serverFileName"]) ."", "WA_BLANK");
$UpdateQuery->bindColumn("horse_pic4", "s", "https://mysupersite.com/horse-sale-2020/".$WADAhorses_update->getColumnVal("horseid") ."/".($WA_DFP_UploadStatus["WA_UploadResult4"]["serverFileName"]) ."", "WA_BLANK");
$UpdateQuery->bindColumn("horse_pic5", "s", "https://mysupersite.com/horse-sale-2020/".$WADAhorses_update->getColumnVal("horseid") ."/".($WA_DFP_UploadStatus["WA_UploadResult5"]["serverFileName"]) ."", "WA_BLANK");
to:
$UpdateQuery->bindColumn("horse_profile_pic", "s", "".($WA_DFP_UploadStatus["WA_UploadResult1"]["serverFileName"]?"https://mysupersite.com/horse-sale-2020/".$WADAhorses_update->getColumnVal("horseid") ."/".($WA_DFP_UploadStatus["WA_UploadResult1"]["serverFileName"]):"") ."", "WA_IGNORE");
$UpdateQuery->bindColumn("horse_pic2", "s", "".($WA_DFP_UploadStatus["WA_UploadResult2"]["serverFileName"]?"https://mysupersite.com/horse-sale-2020/".$WADAhorses_update->getColumnVal("horseid") ."/".($WA_DFP_UploadStatus["WA_UploadResult2"]["serverFileName"]):"") ."", "WA_IGNORE");
$UpdateQuery->bindColumn("horse_pic3", "s", "".($WA_DFP_UploadStatus["WA_UploadResult3"]["serverFileName"]?"https://mysupersite.com/horse-sale-2020/".$WADAhorses_update->getColumnVal("horseid") ."/".($WA_DFP_UploadStatus["WA_UploadResult3"]["serverFileName"]):"") ."", "WA_IGNORE");
$UpdateQuery->bindColumn("horse_pic4", "s", "".($WA_DFP_UploadStatus["WA_UploadResult4"]["serverFileName"]?"https://mysupersite.com/horse-sale-2020/".$WADAhorses_update->getColumnVal("horseid") ."/".($WA_DFP_UploadStatus["WA_UploadResult4"]["serverFileName"]):"") ."", "WA_IGNORE");
$UpdateQuery->bindColumn("horse_pic5", "s", "".($WA_DFP_UploadStatus["WA_UploadResult5"]["serverFileName"]?"https://mysupersite.com/horse-sale-2020/".$WADAhorses_update->getColumnVal("horseid") ."/".($WA_DFP_UploadStatus["WA_UploadResult5"]["serverFileName"]):"") ."", "WA_IGNORE");