Ivermectin is effective against screwworm, both in humans and in animals.
Veterinary ivermectin is currently available and inexpensive. Texas is currently considering a law to legalize over-the-counter ivermectin.
Ivermectin can be used as a preventative.
Good for Texas to do such a thing.
Have to be careful though as it can be absorbed through skin and can overdose IF too much is used. But using small amounts a few times a day is fine.