Kennel Cough Treatment with Trimethoprim-Sulfa

Kennel cough treatment has traditionally been administration of a broad spectrum antibiotic to kill the bacteria. Treatment often meant not only dealing with the dog coughing from the initial infection, but also dealing with multiple side effects caused by the antibiotics treating it. With the development of broad spectrum combination antibiotics like trimethoprim-sulfa, dogs are being cured of kennel cough with less tissue damage and disruption of their systems, which is often caused by the medication they take to get rid of the infection.


Trimethoprim-sulfa combats infection on two fronts. Typically, antibiotics only inhibit the reproduction of the bacterial cells, but doesn’t actually kill the bacteria. The combination of the two antibiotics, trimethoprim and sulfa, sets up a “sequential blockade”. The sequential blockade not only inhibits the reproduction of the bacteria, it also kills the existing bacteria, fighting the infection on two fronts.

Because kennel cough can be caused by several different strains of bacteria, trimethoprim-sulfa is an effective treatment for it. It's a broad spectrum antibiotic and can be utilized to fight bacteria, even if they haven’t been identified. Trimethoprim-sufa also has the added benefit of being able to penetrate infected cells to fight the infection. Traditional antibiotics are stopped by the cell walls, preventing the infection from being attacked inside the cells.

Dogs being treated for kennel cough often develop diarrhea caused by the antibiotic upsetting the flora of the digestive tract. Because trimethoprim-sulfa has minimal impact on the intestinal system, it is less likely that a kennel cough patient will develop diarrhea as a result of treatment.

Side Effects of Trimethoprim-Sulfa

While side effects of trimethoprim-sulfa are rare, when they do occur, they can be quite serious. If your dog is being treated for kennel cough with trimethoprim-sulfa, it's a good idea to become familiar with potential side effects and be prepared should they develop.

  • Hepatitis is a potential side effect of any sulfa drug. Discontinuation of the medication should return the liver to a healthy state.
  • Loss of red blood cells, platelets and white blood cells have also been seen in dogs being treated with trimethoprim-sulfa. Immune system problems and a tendency to bleed are signs that this is taking place.
  • Sulfa bladder stones can develop with the use of trimethoprim-sulfa.
  • Joint inflammation can also be caused by the use of trimethoprim-sulfa. Symptoms include muscle stiffness and arthritis in the joints.
  • Skin rashes can develop due to sensitivity to the medication.
  • Trimethoprim-sulfa can also reduce your dog’s natural tear production. Once the medication is discontinued, normal tear production should return.

Dog owners are seeing great success in treating kennel cough with trimethoprim-sulfa. Because the bacteria are attacked on two fronts, preventing them from reproducing and killing the existing ones, fast and effective results are achieved. Because side effects like diarrhea and skin rashes are rare, trimethoprim-sulfa has become a treatment of choice for kennel cough. Its low impact on your dog’s system provides the necessary treatment to rid your dog’s system of the offending bacteria, while allowing him to remain active and alert.