Oxytetracycline is a highly active broad-spectrum antibiotic that works by inhibiting protein synthesis. Other similar drugs include Chlortetracycline
, and Doxycycline
. Oxytetracycline has activity against gram-positive and gram-negative bacteria, including some anaerobes. It is also active against Chlamydia, Mycoplasmas
, and some protozoa, and several rickettsiae. Specific bacteria within the tetracycline's activity range include Escherichia coli, Klebsiella spp, Pasteurella spp, Salmonella spp, Staphylococcus spp,
and Streptococcus spp
Oxytetracycline can be given in drinking water and feed, or SC or IM. With IM administration there is a risk it can cause muscle irritation or necrosis. After IM administration of oxytetracycline (not long-acting), peak levels may occur in 30 minutes to several hours, depending on the volume and site of injection.
Oxytetracycline is readily absorbed after oral administration in fasting birds. Bioavialabilities are approximately 60-80%. The presence of products or foods containing Al, Ca, Mg, or Fe reduce or alter the absorption of the drug. If given in drinking water, it should simultaneously be given in feed as well.
Unless otherwise directed by the manufacturer, oxytetracycline HCl and oxytetracycline products should be stored in tight, light-resistant containers at temperatures of less than 40°C (104°) and preferably at room temperature (15-30°C); avoid freezing. Note that if this drug is used after its expiration date, it becomes nephrotoxic.
High dosages or chronic administration may delay bone growth and healing in young poultry. Tetracyclines in high levels can exert an antianabolic effect which can cause an increase in BUN and/or hepatotoxicity, particularly in patients with preexisting renal dysfunction. As renal function deteriorates secondary to drug accumulation, this effect may be exacerbated.