Tips and Topics

Oxytet or Oxysol

Oxytet or Oxysol — Oxytetracycline/Terramycin is an antibiotic used in the treatment of American or European foulbrood. Generally treatment is done in spring and fall to prevent or control minor outbreaks of foulbrood disease.

Generally the bees will clean up European foulbrood very readily. American foulbrood is most devastating on the bee brood. This disease is highly contagious and its spores can remain viable indefinitely. If a hive is heavily infected, the best control method is burning of the infected equipment. This will help prevent spread of the disease.

Methods of Use

In syrup — Oxytet or Oxysol can be dissolved in sugar syrup when feeding bees. This method can be effective if bees are using the syrup quickly. However oxytetracycline is unstable in water solution and breaks down quickly. Add 1 litre of hot water to 2 litres of white sugar. Mix to dissolve sugar, then add 1½ teaspoons of the Oxtet-25 or Oxysol 62.5 and mix thoroughly.

Extender patty — Oxytetracycline remains stable for many weeks in extender patties composed of solid vegetable oil, sugar and oxytetracycline. However, the bees do not like the patties and may not consume them, which means they are not getting the appropriate treatment. Therefore, the use of these medicated extender patties is no longer recommended.

Dusting powder — Oxytetracycline remains stable in this form. This method of use gives quick results. The major disadvantage of dusting is that it is difficult to control the drug dosage. Mix 2 tablespoons of icing sugar with 1 teaspoon of Oxytet or Oxysol to treat 1 colony. This medication mixture is then sprinkled (dusted) on the outside frames in a circle on the brood chamber top bars so that it circumscribes the brood nest. Do not dust between the frames where there is open brood, as this will kill the bee larvae. Use approximately 1 ounce (28g) of dusting powder per hive. Repeat treatment every 4 to 5 days until 3 applications have been applied. Can be used spring and fall. One (454g) bag of Oxytet or one (400g) bag of Oxysol, mixed with icing sugar according to package directions will treat approximately 32 colonies.

Foulbrood mix — this is a premixed dusting powder and is applied in the same manner as the above formulation.

Please note as of 2018 Agrifood Canada requires all medically important anti-microbials shall be available only under veterinarian oversight. Please contact your local veterinarian for further information.

  • Fumidil B product literature, Medivet Pharmaceuticals, High River, Alberta, Canada
  • Honey Bee Pests, Predators, and Diseases, 3rd Edition ©1997, edited by Roger A. Morse and Kim Flottum