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Antibiotics for American and European Foulbrood Disease

Division of Plant Industry – Apiculture
8995 East Main Street
Reynoldsburg, Ohio 43068-3399 


Feeding antibiotics to honey bee colonies is the Ohio beekeeper’s management decision. The only F.D.A. approved antibiotic is “Terramycin”, the trade name for oxytetracycline manufactured by Pfizer. Beekeepers can feed in a preventive manner and also as a disease control. Preventive feeding implies that antibiotics are applied to apparently healthy colonies. This is done in the early spring and late fall to avoid any possible honey contamination. As a disease control beekeepers have the option to feed antibiotics or they may dispose of the disease by burning.

What about TerramycinTM

  • It prevents bacterial spore germination or delays germination beyond the time bee larvae can be harmed.
  • Allows the colony to clear out dead brood so symptoms disappear.
  • Antibiotics must be present constantly while larvae are being fed so as to prevent spore germination in healthy larvae or prevent bacterial growth.
  • The use of antibiotics (Terramycin) must always be accompanied by good management.

Important considerations

  • Feed only the recommended dosages of Terramycin.
  • Terramycin loses effectiveness more rapidly when exposed to sunlight.
  • Store Terramycin in a dry, dark refrigerator until used.
  • Do not mix Terramycin into hot syrup. The antibiotic will lose much of its effectiveness.
  • A diseased colony must have sufficient numbers of nurse bees available if the antibiotic (Terramycin) is to be effective.
  • Terramycin should not be fed during a honey flow and all surplus supers must be removed.
  • Prepare Terramycin mixture only as needed and not in advance.

The preferred Terramycin feeding method is to dust the hive frames, using a mixture of the antibiotic and powdered sugar. A method of dissolving Terramycin in syrup and then feeding colonies is used by beekeepers. However, it is not recommended because of Terramycin’s breakdown when in solution and when exposed to light.

The following formulas are suggested for beekeepers choosing to feed Terramycin. Terramycin is readily available at most bee supply dealers.

6.4 oz foil packet

  • 6.4 oz packet TM
  • 1-1/2 pounds powdered sugar

Mix well. Use 2 tablespoons or 1/8 cup per feeding. Feeds about 50 colonies one feeding.  For feeding 1 colony, mix 1 teaspoon of TM plus 5 teaspoons of powdered sugar.

TM 25

  • 1 pound of TM 25
  • 3-3/4 pounds powdered sugar

Mix Well.  Use 2 tablespoons or 1/8 cup per feeding. Feeds about 125 colonies one feeding.

TM 50D

  • 1 pound of TM 50
  • 7-1/2 pounds powdered sugar

Mix Well.  Use 2 tablespoons or 1/8 cup per feeding.  Feeds about 250 colonies one feeding.


Usually 3 dustings at 4-5 day intervals are required in the spring and fall. Use at least 4 weeks before the main honey flow to prevent contamination of marketable honey. Dusting should be directed on the outside edge of the frame top bars in the brood area, avoiding direct contact between the brood and the Terramycin mixture.

Prepared by: Gordon Rudloff
State Apiarist
Ohio Department of Agriculture