There is no one treatment plan that is suitable for every case of strangles. Treatment often revolves around supportive care, good stable management and hygiene. Antibiotics may rarely be used and your veterinary surgeon will give you guidance based on your horse's individual circumstances.
Feeding wet sloppy feed from the floor makes it easier for infected horses to swallow and encourages drainage of pus from the throat area. Hot compresses applied to the abscesses will help bring them to the surface to enable spontaneous rupture or surgical lancing by the veterinary surgeon. Once an abscess has ruptured it will need to be drained and flushed daily with a suitable antiseptic solution.
Potentially infected horses should be isolated as soon as possible to help limit the spread of disease. See Management of Strangles, What To Do In An Outbreak