Hello Everyone!

I am new to the forum but I thought this was the place to go! I am looking for a 5-6 foot, fast growing, drought resistant privacy hedge that is also non toxic to horses. The hedges will get full sun and the soil is very rich.
Thus far I have called my County Extension which did not yield any results besides Sea Grapes which I have owned and found that they are incredibly brittle in high winds and high maintenance. I have looked at Bamboo which some places say are toxic and some sites say are non-toxic.
I have owned Ficus benjamina, which served the privacy hedge barrier for many years. For the past three I have fought to keep them alive. The first wave of problems occurred with the white fly infestation, the second seemed to be a fungus of tiny black spots among the bark, then the third wave of issues was large silver dollar size patches of white splotches growing up the trunk. The root system has been taken over by carpenter ants as well, and nothing is working. I have tried research, I have tried professionals, root drenches - ect and the last resort was to hard prune and hope by removing the diseased and excess growth they will have enough energy to regenerate. Truthfully I do not think they will make it - hence asking about privacy hedges. I have new growth on some but others even though they have new growth the trunks are completely rotted. I really liked these hedges because they were non toxic and easy keepers up until now.
Any thoughts or ideas? I have looked at native Florida Plants but most are toxic to the animals. I have a Fence line that is electrified yet some how the horses always manage to worm though the fence and get some of the hedges - the grass is always greener on the other side!
Thanks!
-Fae