The new prescription drugs from Merck Animal Health are broad-spectrum medications for combating organisms that cause the illness.

Officials with the FDA have approved florfenicol injectable solution (Nuflor-S; Merck Animal Health) and tulathromycin injection (Arovyn; Merck Animal Health). These broad-spectrum, prescription antibiotics treat the major organisms associated with swine respiratory disease (SRD), according to Merck.

Both drugs are prescription antibiotics indicated for use in swine, and tulathromycin injection is also indicated for cattle, according to Merck. These treatments will be available from or on the order of a licensed veterinarian in 100-mL vials (florfenicol injectable solution) and in 100-, 250- and 500-mL vials (tulathromycin injectable solution).

Florfenicol injectable solution

Florfenicol 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.

Florfenicol injectable solution should not be used in animals intended for breeding purposes. Perianal inflammation, rectal eversion, rectal prolapse, and diarrhea may occur transiently following treatment, according to Merck. Additionally, 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.

Tulathromycin injectable solution

Tulathromycin 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.

This drug should not be used in animals known to be hypersensitive to the product. In cattle, tulathromycin injectable solution has a preslaughter withdrawal time of 18 days. This drug should not be used in female dairy cattle 20 months of age or older. In swine, the preslaughter withdrawal time for tulathromycin injectable solution is 5 days.