The VFD regulations require a prescription for all antibiotic feed additives and can be used only for “treatment,” “control” or “prevention.” All antibiotic feed additives that are medically important to humans in any way would lose usage intended for production purposes such as improved weight gain and improved feed efficiency.

Griffin dee
Veterinarian / Texas Veterinary Medical Center – Texas A&M University

Pulmotil is the first antibiotic feed additive for cattle approved by the FDA for use under their VFD regulations. Pulmotil contains the same active ingredient, tilmicosin, as the injectable Micotil.

Pulmotil is approved by the FDA for bovine respiratory disease (BRD) “control” for groups of cattle in the early stages (as soon as 10 percent are affected) of a BRD outbreak associated with Mannheimia haemolytica, Pasteurella multocida and Histophilus somni.

A Pulmotil prescription is valid for 45 days from issuance or the effective date noted on the VFD by the veterinarian.

Once BRD is diagnosed in at least 10 percent of the group of cattle, Pulmotil can be fed for 14 days. The approval requires Pulmotil to be fed for a full 14-day treatment regimen.


The window for initiating Pulmotil use is during the first 45 days after cattle have arrived at a confinement feeding facility. Therefore, if Pulmotil treatment is initiated on day 45, the group would finish the regimen completely on day 59 of the feeding period.

To use Pulmotil for BRD, or any other VFD antibiotic, the owner’s veterinarian must be licensed to practice in the state in which the cattle reside. Diagnosis of BRD in a group of cattle must be consistent with the BRD diagnostic protocol established by the cattle owner’s veterinarian.

That means the veterinarian must outline in writing the disease signs they want the cattle owner’s key employees to identify in order to establish a diagnosis of BRD in a cattle group.

The signs can all be visual, therefore the FDA does not require cattle to be removed from the group for physical examination nor record rectal temperatures to diagnose BRD. Their veterinarian’s written BRD diagnostic protocol must be on file in the cattle operation’s office.

Additionally, their veterinarian must have trained the identified key employees on how to use their BRD diagnostic protocol.

Once BRD is diagnosed in 10 percent of cattle in a group, Pulmotil can be used. There are two exclusions: Pulmotil, a macrolide-class antibiotic, cannot be used if a different macrolide has been previously used in the cattle group.

For example, if a macrolide such as Draxxin, Micotil, Tylan, Zactran or Zuprevo was given to the cattle on arrival as metaphylaxis (mass medication), Pulmotil could not be used on the group.

Pulmotil also cannot be given to an animal within three days of having received a non-macrolide antibiotic. Therefore, if the group had been mass-medicated with Excede on arrival or fed chlortetracycline (CTC), three days would have had to elapse between the previous antibiotic treatment and the first feeding of Pulmotil.

Since the feed additive Tylan is also in the macrolide class of antibiotics, it should not be included in the ration during the 14-day Pulmotil treatment period.

Pulmotil is not intended to treat cattle suffering from severe BRD, therefore if an animal begins exhibiting severe BRD signs while being fed Pulmotil, the cattle with the severe BRD signs should be removed from the cattle group for individual treatment. The BRD treatment selected for an animal removed from a group being fed Pulmotil must be a non-macrolide antibiotic.

Non-macrolide antibiotic examples include: Excede, Excenel, Nuflor and oxytetracycline. Once the treatment for severe BRD has ended, the treated animal may be returned to the group of cattle being fed Pulmotil, and the three-day delay between a non-macrolide antibiotic does not apply to the individually treated animal that was treated while being fed Pulmotil. Note: Pulmotil has a 28-day withdrawal before treated cattle can enter the food chain.

To use Pulmotil, it must be included in a TMR. No additional feedstuffs can be available for the cattle to eat. Therefore, supplemental forage in hay feeders, energy and mineral supplement tubs must be removed while using Pulmotil.

The 5.68 mg per pound dose of Pulmotil must be delivered to the cattle in the TMR at between 1.5 and 2 percent of the average weight (BW) of the cattle group on a dry matter (DM) basis.

For example: If the TMR is 67 percent DM (33 percent moisture), average cattle BW is 500 pounds, and they will eat between 1.5 percent and 2 percent of their BW on a DM basis, then the Pulmotil dose would be delivered in between 11.2 and 15 pounds, of as-fed feed.

500 pounds x 1.5 percent BW
= 7.5 pounds feed DM
7.5 pounds of dry feed / 0.67 moisture = 11.2 pounds of as-fed TMR

500 pounds x 2 percent BW
= 10 pounds feed DM
10 pounds of dry feed / 0.67 moisture = 15 pounds of as-fed TMR

My observations – as well as the observations of some of the leading beef stocker and feeder cattle nutritionists – over the decades of working with newly received cattle in confinement feeding facilities are that the 1.5 percent to 2 percent DM intake window the FDA requires for using Pulmotil will typically occur between seven days after arrival (days on feed) and 21 days on feed.

There are groups whose intake will stay below 2 percent out to 28 days on feed, but these group are not typical and most often associated with mismanaged or never-managed commingled, high-stressed cattle.

Intakes during the first seven days on feed can be inconsistent, and beyond 21 days on feed the aggression at the feedbunk caused by limiting cattle to 2 percent of their BW on a DM basis will lead the more aggressive cattle to overconsume the 2 percent BW limit and therefore over- consume Pulmotil, which leads to less ration available to the more timid and sickly cattle in the group – and therefore underdosing of Pulmotil to the cattle that most likely need the medication.

Considering eating behavior, I would not suggest starting a 14-day Pulmotil treatment regimen after cattle are 14 days on feed. For what it is worth, if the cattle were healthy on arrival, the BRD incubation is typically five to seven days, so starting Pulmotil prior to five to seven days would generally not be required unless they come off truck meeting the 10 percent BRD diagnosis threshold.

Pulmotil is available to beef cattle raisers in three different concentrations: Type “A” article that contains 90.7 grams of tilmicosin per pound, Type “B” article that contains 18.1 grams of tilmicosin per pound, and Type “B” article that contains 5.68 grams of tilmicosin per pound.

You will see Type “C” feed or Type “C” article referred to in Elanco’s instructions for use or in FDA Pulmotil use documents. Type “C” is the final mixed medicated ration or feed (TMR) containing the Pulmotil that will be delivered to the cattle being treated with Pulmotil.

Type “A” article requires a feeding facility to have an FDA “Medicated Feed Mill License,” therefore most cattle managers will elect to use a Type “B” article, which doesn’t require having a licensed facility. The Type “B” article containing 18.1 grams per pound tilmicosin uses corn cob as a carrier and may not mix will in TMR containing wet distillers grains.

The Type “B” article containing 5.68 grams per pound tilmicosin comes as a pellet and generally mixes well in all rations. Additionally, the 5.68 gram Pulmotil pellet use calculation is simple because 1 pound of this pellet is the dose required for 1,000 pounds of cattle.

The “formula” for using Type “B” 5.68 grams per pound pellets:

Number of Cattle x their average BW / 1,000 = pounds of Type “B” 5.68 grams per pound pellets to be fed daily to this group for each of the 14 days

For example, if a group of 100 cattle that have an average weight of 500 pounds is to be treated – (100 x 500)/1000 = 50, a 50-pound bag of Type “B” 5.68 grams per pound pellets would be the daily dose for this group.

Note: To prevent carryover between groups, a “flushing” protocol must be established for feed mixing and delivery equipment.

Summary points

  • Pulmotil requires a veterinary feed directive (prescription) and is valid for 45 days from issuance or the effective date noted on the VFD.
  • Pulmotil is for control of BRD in confinement feeding cattle groups that have had at least 10 percent diagnosed with clinical BRD.
  • BRD diagnosis must meet the cattle operation’s licensed veterinarian written diagnostic protocol and the written protocol must be on file at the cattle operations.
  • Pulmotil must be used in a TMR, and no supplemental ration or roughage can be provided.
  • The cattle operation’s key BRD employees making the BRD diagnosis must have been trained by the operation’s licensed veterinarians, and their training documentation must be on file at the cattle operations.
  • Cattle cannot be treated with Pulmotil if they have previously received a macrolide-class antibiotic while at the cattle operation or within three days of being treated with a non-macrolide antibiotic.
  • Pulmotil is not intended for treatment of cattle with severe BRD, therefore an animal developing severe BRD while being treated with Pulmotil should be removed from the group and treated individually with a non-macrolide class antibiotic and then returned to the group being treated with Pulmotil.
  • Pulmotil Type “C” TMR must be fed at between 1.5 percent and 2 percent of average BW on a DM basis.
  • Pulmotil treatment must be initiated within the first 45 days after arrival.
  • Pulmotil must be fed for the full 14-day treatment regimen.
  • Pulmotil has a 28-day withdrawal before treated cattle can enter the food chain.
  • Appropriate flushing protocol should be documented and utilized.  end mark

References omitted due to space but are available upon request. Click here to email an editor.

—Excerpts from University of Nebraska – Lincoln BeefWatch website

Dee Griffin
  • Dee Griffin
  • Feedlot Veterinarian and Professor
  • Great Plains Veterinary Educational Center