Zactran® (gamithromycin)

Treat and control bovine respiratory disease in cattle


ZACTRAN is an antibiotic that fights back against all the major BRD-causing bacteria:

  • ZACTRAN treats BRD associated with Mannheimia haemolytica, Pasteurella multocida, Histophilus somni and Mycoplasma bovis in beef and non-lactating dairy cattle.
  • ZACTRAN controls respiratory disease in beef and non-lactating dairy cattle at high risk of developing BRD associated with M. haemolytica and P. multocida.

Visit to learn more.

Features & Benefits

Keep more of your hard-earned profits with ZACTRAN antibiotic

ZACTRAN controls and treats BRD so cattle get on feed quickly and keep gaining weight. 

With ZACTRAN, you typically see improvement within 24 hours* 

Cattle treated with ZACTRAN in a study had lower temperatures, were more alert and were breathing easier within 24 hours.1 

Treat cattle with one cost-effective dose 

ZACTRAN is competitively priced, and a single dose goes a long way, providing 10 days of BRD treatment or control. Use our pricing calculator to compare costs with your current treatment. 

Reaches the site of infection in just 30 minutes3** 

After you administer ZACTRAN, the broad-spectrum antibiotic rapidly reaches the site of infection — the pulmonary epithelial lining fluid (PELF) of the lungs — where it kills bacteria and stops them from replicating. 

The convenience of 10 days of therapy from a single injection

ZACTRAN keeps working for 10 days, reducing the time and labor associated with repulls. With less animal handling, cattle experience less stress and setback so they can put more energy into gaining weight. 

* A small percentage of cattle may have already suffered lung damage, and may be too far gone or will require a little longer to turn around. 
** Clinical relevance has not been determined. 

Dosage & Administration

  • Administer ZACTRAN one time as a subcutaneous injection in the neck at 2 mL/110lbs (1.8mL/100lbs) body weight (BW). If the total dose exceeds 10 mL, divide the dose so that no more than 10 mL is administered at each injection site. 

  • ZACTRAN is available in 500, 250 and 100 mL sizes.  
    The 500-, 250- and 100-mL bottles contain sufficient solution to treat 55, 28 and 11 head of 500-pound cattle, respectively. 

ZACTRAN Dosing Chart (PDF)


Safety Information

For use in cattle only. Do not treat cattle within 35 days of slaughter. Because a discard time in milk has not been established, do not use in female dairy cattle 20 months of age or older, or in calves to be processed for veal. The effects of ZACTRAN on bovine reproductive performance, pregnancy and lactation have not been determined. 

Adverse Reactions: Transient animal discomfort and mild to moderate injection site swelling may be seen in cattle treated with ZACTRAN. 
Storage: Store at or below 77 °F (25 °C) with excursions between 59-86 °F (15-30 °C). Use within 18 months of first puncture. 

WARNING: FOR USE IN CATTLE ONLY. NOT FOR USE IN HUMANS. KEEP THIS AND ALL DRUGS OUT OF THE REACH OF CHILDREN. NOT FOR USE IN CHICKENS OR TURKEYS. The material safety data sheet (MSDS) contains more detailed occupational safety information. To contact the Veterinary Technical Solutions Team in case of questions or concerns, please call 1-888-637-4251. 

Zactran 30-24-10 Graphic
Zactran 30-24-10 Graphic

A New Approach to Managing High-Risk Cattle

The concept of using metrics to narrow antibiotic use from entire groups of cattle to individual high-risk calves is gaining popularity. Limiting antibiotic use has the potential to reduce costs and promote antimicrobial stewardship.

Farmer pushing fence closed

The Advantage of
Zactran® (gamithromycin)

Use our calculator to compare the cost of ZACTRAN with your current treatment.


Bottle of Zactran

1. Sifferman RL, Wolff WA, Holste JE, et al. Field efficacy evaluation of gamithromycin for treatment of bovine respiratory disease in cattle at feedlots. Intern J Appl Res Vet Med 2011;9(2):171-180.

2. ZACTRAN product label.

3. Giguere S, Huang R, Malinski TJ, et al. Disposition of gamithromycin in plasma, pulmonary epithelial lining fluid, bronchoalveolar cells and lung tissue in cattle. Am J Vet Res 2011;72(3):326-330.


ZACTRAN® is a registered trademark of the Boehringer Ingelheim Group. ©2021 Boehringer Ingelheim Animal Health USA Inc., Duluth, GA. All Rights Reserved.  US-BOV-0138-2021