Herbs to Draw out Infection

My girlfriend has a dog with an infection in his foot caused by fox tails getting caught in his paws outside. Is there anything you can suggest to make a salve to help draw out the infection in his paws? Right now we have been soaking his paws in water with Betadine and Epsom salts for twenty minutes and applying a triple antibiotic ointment, covering them with gauze and trying to keep them clean. Anything you could suggest would be greatly appreciated.

Assuming that there is not an open wound, I would use a clay poultice to draw out the infection and heal the foot. To use clay for this purpose, make a strong tea with an antimicrobial and healing herb such as plantain or echinacea. Let the tea steep for 30 to 45 minutes, then mix with the clay to form a sloppy paste. There should be enough paste to place it about half an inch thick over the wound. Apply the paste to the wound, wrap with gauze, then wrap a stronger cloth, such as a tea towel, around snuggly to keep in place. Replace clay when dried. This should be after about 4 hours. The poultice can be left in place overnight.
Clay for this purchase can be purchased at health food stores, or you can dig it up from the ground. If you dig your own clay, dig a hole 12 to 18 inches deep first, to ensure that the clay contains no organic material.