Once the nature of the allergy is determined, the cause can possibly be removed from the dog s every day life. If the allergy is from things that are uncontrollable such as pollen, grass and mold spores, the veterinarian can arrange to have an antigen made up specifically for the dog. This will be administered by injection and will usually show dramatic results. Abscesses are pockets of pus under the skin. They are often caused by a bite or puncture wound that closed up trapping bacteria inside.
Snakebites are notorious for causing abscesses.
Occasionally an abscess will burst open on its own and allow for drainage, others will need a veterinarian to lance and clean it out. Bacterial infections are often a secondary infection to another conditions. A dog that has scratched or rubbed at an area and left opened skin without proper cleansing or antibiotic treatment will often have a bacterial infection set in. The infected area or wound becomes red, swollen, warm to the touch and very painful. This infection can worsen and cause a discharge of pus that will require a veterinarian to treat.