Antibiotics are not a cure-all in bacterial infections — they're just one component of a whole-dog approach to fighting infection. Treatment of bacterial infections may fail for many reasons. Here are the more common ones:

• The bacteria are resistant to the antibiotic.
• The bacteria live inside cells and, thus, are not exposed to the antibiotic.
• The antibiotic couldn't penetrate to the center of the infected area.
• An inappropriate dose or route of administration was prescribed.
• The prescribed dosage regimen was not reliably followed.
• The animal's own defense mechanisms were compromised by malnutrition, disease, or concurrent treatment by immunosuppressive drugs such as corticosteroids.
• The antibiotic had to be withdrawn due to adverse side effects.
• Supportive therapy, nutrition, or nursing care was inadequate.

As with all medical treatments for your pup, work closely with a veterinarian with whom you have established an open, trusting relationship — for your pet's good care and your own peace of mind.