Wrong type of worms. These are fly larva. Invermectin is useful against intestinal and heartworms.
This old study found ivermectin efficacious in treating screw worm infected cattle:
https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1751-0813....
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This old study found ivermectin efficacious in treating screw worm infected cattle:
https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1751-0813....