Merck Animal Health Receives FDA Approval of NUFLOR®-S (florfenicol) and AROVYN™ (tulathromycin injection)

New prescription antibiotics provide swine veterinarians and producers options for treating swine respiratory disease.

Merck Animal Health, known as MSD Animal Health outside the United States and Canada, a division of Merck & Co., Inc., Kenilworth, New Jersey, USA (NYSE:MRK), announced it has received U.S. FDA approval of NUFLOR®-S (florfenicol) Injectable Solution and AROVYN (tulathromycin injection) – broad-spectrum, prescription antibiotics that treat the major organisms associated with swine respiratory disease (SRD).

“Merck Animal Health is pleased to expand our portfolio of offerings with two antimicrobials to help veterinarians and producers combat SRD,” said Doug King, D.V.M., Associate Director of the Swine Technical Services, Merck Animal Health. “We are committed to partnering with veterinarians and swine producers and offering comprehensive solutions that lead to improved animal health outcomes and welfare. Expanding our portfolio to include antimicrobials further enables us to accomplish this goal.”

NUFLOR-S Injectable Solution is indicated for treatment of SRD associated with Actinobacillus pleuropneumoniae, Pasteurella multocida, Salmonella Choleraesuis, Streptococcus suis, Bordetella bronchiseptica, and Glaesserella (Haemophilus) parasuis in swine except for nursing piglets and swine of reproductive age intended for breeding.  AROVYN Injectable Solution is indicated for the treatment of SRD associated with Actinobacillus pleuropneumoniae, Pasteurella multocida, Bordetella bronchiseptica, Haemophilus parasuis, and Mycoplasma hyopneumoniae; and for the control of SRD associated with Actinobacillus pleuropneumoniae, Pasteurella multocida, and Mycoplasma hyopneumoniae in groups of pigs where SRD has been diagnosed.

NUFLOR-S – a prescription antibiotic for swine, and AROVYN — a prescription antibiotic for cattle and swine – will be available from or on the order of a licensed veterinarian. NUFLOR-S will come in 100-mL vials and AROVYN will come in 100-, 250- and 500-mL vials.


Do not use in animals intended for breeding purposes. Perianal inflammation, rectal eversion, rectal prolapse and diarrhea may occur transiently following treatment. Swine intended for human consumption must not be slaughtered within 11 days of the last intramuscular treatment. Intramuscular injection may result in trim loss of edible tissue at slaughter. The effects of florfenicol on porcine reproductive performance, pregnancy and lactation have not been determined. Not for human use and keep away from children. Avoid direct contact with skin, eyes, and clothing. Pregnant women should wear gloves and exercise caution or avoid handling this product. See reverse for full prescribing information.


CATTLE: AROVYN has a pre-slaughter withdrawal time of 18 days in cattle. Do not use in female dairy cattle 20 months of age or older. Do not use in animals known to be hypersensitive to the product. See full Prescribing Information.

SWINE: The pre-slaughter withdrawal time for AROVYN in swine is five days. AROVYN should not be used in animals known to be hypersensitive to the product.