I've used Cowboy Magic detangler, and Bella did fine with it, but I don't know whether or not it's hypoallergenic. It was originally made for horses, but it's safe to use on all animals, and humans too. See:
https://www.chewy.com/s?rh=brand_fac...SAAEgJMxfD_BwE https://cowboymagic.com/products/cow...tangler-shine/