While it would have been a worthy research project to determine how to cure them, Twilight knew her limitations: when it came to anything beyond basic first aid, she was hopelessly lost.  Applejack probably knew more field medicine than she did—after all, there was little enough in the library which posed immediate danger to life and limb, and it was quite honestly a subject which she felt should remain in the hooves of the professionals.  Surgery was not an art in which one dabbled, after all.