Bovine respiratory disease in feedlot calves: first-line antimicrobial comparison — POSSIBLE

In feedlot calves with clinical bovine respiratory disease, how do first-line antimicrobials (tulathromycin vs florfenicol vs tilmicosin and successors) compare for first-treatment success and relapse?

Shelf #155 · gate-verified and approved by the developer

POSSIBLE: The manufacturer-run randomised trials consistently favour tulathromycin for first-treatment success: sustained improvement at day 14 was similar to florfenicol in European cattle (83.3% vs 81.0%) with fewer relapses by day 60 (no-relapse 63.3% vs 58.4%), while US stocker and feedlot studies report cure rates significantly higher than florfenicol and, in most comparisons, tilmicosin — though those two abstracts report significance without cure-rate percentages. An independent Nebraska feedlot trial found first relapse, overall mortality and BRD mortality relative risks of 0.65, 0.33 and 0.29 favouring tulathromycin over florfenicol (absolute rates not given in the record). Against that, an independent Alberta trial found no significant differences in relapses or crude case fatality between florfenicol and tulathromycin, with a lower BRD/Histophilus case fatality rate for florfenicol. Three of the five carded studies carry Pfizer affiliations on the record (Pfizer made tulathromycin), and no carded record establishes blinded outcome assessment, which together cap this shelf at POSSIBLE. This shelf covers treatment of clinical BRD only; metaphylaxis/prevention in high-risk cattle is topic #14's home, and the prevention phases of the carded programmes are not carded here. Drafted Nov 10, 2026 (VetMed build, topic #155); all figures from abstracts fetched and verified at drafting.

Godinho 2005: tulathromycin vs florfenicol for clinical BRD in European cattle — improvement at day 14 similar (83.3% vs 81.0%), fewer relapses by day 60 (no-relapse 63.3% vs 58.4%)

Randomized controlled trial, multicentre (record's own publication types)

Who: Cattle: commingled cattle with clinical bovine respiratory disease on commercial farms in France, Germany, Italy and Spain, treated on day 0 with tulathromycin (n = 128) or florfenicol (n = 125) in phase 1 (treatment) of the study; the record's author affiliations include Veterinary Medicine Research and Development, Pfizer Ltd, Sandwich, Kent, UK.

Result: Similar percentages of animals showed sustained clinical improvement at day 14 (tulathromycin 83.3% versus florfenicol 81.0%) and had not relapsed by day 60 (tulathromycin 63.3% versus florfenicol 58.4%). The authors concluded tulathromycin was highly effective in the treatment of BRD.

Watch out: Only phase 1 (treatment of clinical BRD) is carded here; phase 2 of the same paper treated healthy in-contact cattle (prevention/metaphylaxis), which is topic #14's home and is not part of this shelf's question. The abstract gives percentages without significance tests for the phase 1 comparisons, and neither randomisation method nor assessor blinding is described in the record — blinding is not claimed. Sponsor affiliation (Pfizer Ltd) is as shown on the record.

Godinho KS, Wolf RM, Sherington J, Rowan TG, Sunderland SJ, Evans NA. Efficacy of tulathromycin in the treatment and prevention of natural outbreaks of bovine respiratory disease in European cattle. Vet Ther. 2005;6(2):122-35. PMID: 16094560. Registry ID: none in the record. MeSH: Animals · Anti-Bacterial Agents/administration & dosage,therapeutic use · Cattle · Disaccharides/administration & dosage,therapeutic use · Disease Outbreaks/prevention & control,veterinary · Europe/epidemiology · Haemophilus somnus/isolation & purification · Heterocyclic Compounds/administration & dosage,therapeutic use · Injections, Subcutaneous/veterinary · Macrolides/administration & dosage,therapeutic use · Mannheimia haemolytica/isolation & purification · Mycoplasma bovis/isolation & purification · Pasteurella multocida/isolation & purification · Pasteurellosis, Pneumonic/drug therapy,epidemiology,microbiology,prevention & control · Thiamphenicol/administration & dosage,analogs & derivatives,therapeutic use · Tylosin/administration & dosage,analogs & derivatives,therapeutic use

Nutsch 2005: in 800 stocker calves with BRD, the 60-day cure rate with tulathromycin was significantly higher than with florfenicol or tilmicosin (percentages not reported)

Randomized controlled trial, multicentre comparative study (record's own publication types)

Who: Cattle: 800 stocker calves exhibiting clinical signs of bovine respiratory disease with rectal temperatures of 104°F or higher, in three field studies over two consecutive grazing seasons in Nebraska, treated with a single subcutaneous injection of tulathromycin 2.5 mg/kg (n = 340), florfenicol at labeled dosage (n = 240), or tilmicosin at labeled dosage (n = 220), and evaluated for approximately 60 days; the record's author affiliations include Pfizer Animal Health, Veterinary Medicine Research and Development, Kalamazoo, MI, USA.

Result: In all three studies, the cure rate of calves 60 days after treatment with tulathromycin was significantly higher (P ≤ .05) than that of calves treated with florfenicol or tilmicosin. Suspected adverse reactions were not reported for any of the study drugs. The authors concluded tulathromycin proved significantly more effective than either florfenicol or tilmicosin in the treatment of BRD in stocker calves.

Watch out: The abstract reports that the cure-rate difference was significant but gives no cure-rate percentages for any group, so the size of the advantage cannot be stated from this record — significance without magnitude. These are stocker (grazing) calves, not feedlot pens. Assessor blinding is not described in the record; sponsor affiliation (Pfizer Animal Health) is as shown on the record.

Nutsch RG, Skogerboe TL, Rooney KA, Weigel DJ, Gajewski K, Lechtenberg KF. Comparative efficacy of tulathromycin, tilmicosin, and florfenicol in the treatment of bovine respiratory disease in stocker cattle. Vet Ther. 2005;6(2):167-79. PMID: 16094564. Registry ID: none in the record. MeSH: Animals · Anti-Bacterial Agents/administration & dosage,therapeutic use · Cattle · Disaccharides/administration & dosage,therapeutic use · Heterocyclic Compounds/administration & dosage,therapeutic use · Injections, Subcutaneous/veterinary · Macrolides/administration & dosage,therapeutic use · Male · Pasteurellosis, Pneumonic/drug therapy,pathology · Recurrence · Severity of Illness Index · Thiamphenicol/administration & dosage,analogs & derivatives,therapeutic use · Treatment Outcome · Tylosin/administration & dosage,analogs & derivatives,therapeutic use · United States · Weight Gain

Skogerboe 2005: feedlot cure rates were significantly higher with tulathromycin than florfenicol at both sites, and higher than tilmicosin at one of two sites

Randomized controlled trial, multicentre comparative study (record's own publication types)

Who: Cattle: calves with undifferentiated bovine respiratory disease at feedlots in Greeley and Wellington, Colorado; Nebraska; and Texas — in each study 100 calves treated with tulathromycin 2.5 mg/kg s.c.; 100 calves per site treated with florfenicol 40 mg/kg s.c. at Greeley and Nebraska, and 100 per site with tilmicosin 10 mg/kg s.c. at Wellington and Texas; cure rate was a derived variable including mortality, rectal temperature, and attitude and respiratory scores from day 3 to day 28 and day 3 through harvest. The record's author affiliations include Pfizer Animal Health, Veterinary Medicine Research and Development, Kalamazoo, MI, USA.

Result: Cure rates of calves treated with tulathromycin were significantly (P ≤ .009) higher than those of calves treated with florfenicol. At Wellington, Colorado, the cure rate with tulathromycin was significantly higher (P ≤ .018) than with tilmicosin; in the Texas study, the difference between tulathromycin and tilmicosin was not significant (P > .05). The authors concluded tulathromycin was more efficacious than florfenicol and, in one study, than tilmicosin for undifferentiated BRD.

Watch out: As with Nutsch 2005, the abstract reports significance (P values) without any cure-rate percentages, so the absolute size of the differences is not available from this record. 'Cure' is a derived composite that includes mortality and subjective attitude/respiratory scores; assessor blinding is not described in the record, and the tilmicosin comparison was inconsistent across the two sites that ran it. Sponsor affiliation (Pfizer Animal Health) is as shown on the record.

Skogerboe TL, Rooney KA, Nutsch RG, Weigel DJ, Gajewski K, Kilgore WR. Comparative efficacy of tulathromycin versus florfenicol and tilmicosin against undifferentiated bovine respiratory disease in feedlot cattle. Vet Ther. 2005;6(2):180-96. PMID: 16094565. Registry ID: none in the record. MeSH: Animals · Anti-Bacterial Agents/administration & dosage,therapeutic use · Cattle · Disaccharides/administration & dosage,therapeutic use · Heterocyclic Compounds/administration & dosage,therapeutic use · Injections, Subcutaneous/veterinary · Macrolides/administration & dosage,therapeutic use · Male · Pasteurellosis, Pneumonic/drug therapy,pathology · Recurrence · Severity of Illness Index · Thiamphenicol/administration & dosage,analogs & derivatives,therapeutic use · Treatment Outcome · Tylosin/administration & dosage,analogs & derivatives,therapeutic use · United States · Weight Gain

Schunicht 2007: in 200 feedlot calves with undifferentiated fever, tulathromycin's first relapse and mortality relative risks were 0.65, 0.33 and 0.29 vs florfenicol

Randomized controlled trial (record's own publication types; abstract states calves were randomly allocated in a 1:1 ratio)

Who: Cattle: 200 recently weaned, auction-market-derived, crossbred beef calves under commercial feedlot conditions in central Nebraska, meeting a study case definition of undifferentiated fever, that had not received a metaphylactic antimicrobial or Mannheimia haemolytica/Histophilus somni vaccines at arrival, randomly allocated 1:1 to tulathromycin 2.5 mg/kg s.c. once or florfenicol 40 mg/kg s.c. once at allocation.

Result: The first undifferentiated-fever relapse relative risk (RR = 0.65), overall mortality relative risk (RR = 0.33), and BRD mortality relative risk (RR = 0.29) in the tulathromycin group were significantly (P < 0.05) lower than in the florfenicol group — i.e., relative risks, with the abstract giving no absolute rates for these outcomes. There were no significant differences (P ≥ 0.05) between groups for the other animal-health variables measured, and no significant difference in average daily gain. The authors calculated an economic advantage of $52.50 USD per animal for the tulathromycin group from the lower relapse and mortality rates, despite a higher initial treatment cost.

Watch out: All three headline effects are relative risks only — the record's abstract does not give the underlying absolute relapse or mortality rates, so the absolute benefit cannot be computed from this record, and a relative risk of 0.33 on a low absolute mortality rate is a small absolute gain. The case definition is undifferentiated fever (a BRD proxy), not confirmed BRD. Assessor blinding is not stated in the record. Author affiliations on the record are a feedlot health management service, not the manufacturer.

Schunicht OC, Booker CW, Guichon PT, Jim GK, Wildman BK, Pittman TJ, Perrett T. An evaluation of the relative efficacy of tulathromycin for the treatment of undifferentiated fever in feedlot calves in Nebraska. Can Vet J. 2007;48(6):600-6. PMID: 17616056. Registry ID: none in the record. MeSH: Animals · Anti-Bacterial Agents/therapeutic use · Cattle · Disaccharides/therapeutic use · Heterocyclic Compounds/therapeutic use · Injections, Subcutaneous/veterinary · Nebraska · Pasteurellosis, Pneumonic/drug therapy,mortality · Recurrence · Thiamphenicol/analogs & derivatives,therapeutic use · Treatment Outcome · Weight Gain · Macrolides

Van Donkersgoed 2008: in Alberta feedlot calves, florfenicol vs tulathromycin showed no significant differences in relapses or crude case fatality — and lower BRD/Histophilus case fatality with florfenicol

Comparative field study (record's publication types do not include Randomized Controlled Trial; MeSH includes Random Allocation; abstract does not state randomisation or blinding)

Who: Cattle: fall-placed steer calves in Alberta feedlots that had received metaphylactic tilmicosin on arrival, treated for undifferentiated fever with florfenicol or tulathromycin as initial treatment; the record's author affiliation is Alberta Beef Health Solutions Inc, Picture Butte, Alberta, Canada. The record's MeSH includes Random Allocation; the abstract does not state the allocation method or group sizes.

Result: No significant differences (P > .10) were observed in undifferentiated fever relapses or the crude case fatality rate. Calves treated with florfenicol had a lower case fatality rate (P = .04) for bovine respiratory disease and Histophilus disease than calves treated with tulathromycin. The net economic advantage of florfenicol over tulathromycin was Can$17.70 per treated animal, based on differences in trial drug costs and calf replacement owing to BRD and Histophilus case fatality.

Watch out: The counterweight card: an independent (non-manufacturer-affiliated) comparison that did not reproduce the tulathromycin advantage on relapses or crude fatality, and found one fatality outcome favouring florfenicol. Its abstract reports no rates or group sizes, so effect sizes cannot be quoted, and because its publication types do not index it as a randomised trial, randomisation rests on the record's MeSH Random Allocation term alone. All calves had already received metaphylactic tilmicosin on arrival, which may blunt differences between first-treatment drugs.

Van Donkersgoed J, Berg J, Hendrick S. Comparison of florfenicol and tulathromycin for the treatment of undifferentiated fever in Alberta feedlot calves. Vet Ther. 2008;9(4):275-81. PMID: 19177332. Registry ID: none in the record. MeSH: Alberta/epidemiology · Animals · Animals, Newborn · Anti-Bacterial Agents/economics,pharmacology · Bovine Respiratory Disease Complex/drug therapy,mortality · Cattle · Cost-Benefit Analysis · Disaccharides/economics,pharmacology · Heterocyclic Compounds/economics,pharmacology · Male · Random Allocation · Risk Factors · Thiamphenicol/analogs & derivatives,economics,pharmacology · Treatment Outcome · Macrolides

Synthesis: manufacturer trials favour tulathromycin on cure/relapse; the one independent head-to-head found no relapse or crude-fatality difference — and no trial establishes blinded assessment

Synthesis

Who: Synthesis of the cards above: Godinho 2005 (253 European cattle with clinical BRD, treatment phase), Nutsch 2005 (800 stocker calves, Nebraska), Skogerboe 2005 (feedlot calves at four sites in Colorado, Nebraska and Texas), Schunicht 2007 (200 feedlot calves, Nebraska, randomly allocated) and Van Donkersgoed 2008 (Alberta feedlot steer calves).

Result: On first-treatment success, tulathromycin matched florfenicol on day-14 improvement in Europe (83.3% vs 81.0%) with a modest no-relapse edge by day 60 (63.3% vs 58.4%), and was reported significantly superior on composite cure rates in the US stocker and feedlot programmes — but two of those three abstracts give no percentages, so the size of the US advantage is unverifiable from the records. On relapse, the independent Nebraska trial's relative risk was 0.65 favouring tulathromycin over florfenicol, while the independent Alberta trial found no significant relapse difference. On mortality, one trial reports relative risks of 0.33 (overall) and 0.29 (BRD) favouring tulathromycin without absolute rates, while the Alberta trial found no crude-fatality difference and a lower BRD/Histophilus case fatality rate with florfenicol (P = .04).

Watch out: Anchor and scope corrections versus the draft: (1) the companion Pfizer programme paper on high-risk cattle (PMID: 16094563) is metaphylaxis — treatment before signs of BRD — so it belongs to prevention topic #14 and is deliberately NOT carded here; only treatment phases and treatment trials are carded. (2) Industry sponsorship is as the records show it: Pfizer affiliations appear on the Godinho, Nutsch and Skogerboe records, and no carded record states that outcome assessors were blinded, so this shelf is classed randomised with blinding not established. (3) Two carded abstracts report significance without rates, which is why this shelf stamps POSSIBLE rather than higher despite consistent direction in the sponsored trials.

Synthesis of Godinho KS et al. PMID: 16094560; Nutsch RG et al. PMID: 16094564; Skogerboe TL et al. PMID: 16094565; Schunicht OC et al. PMID: 17616056; Van Donkersgoed J et al. PMID: 19177332. Registry IDs as on the individual cards.

Back to the library index · VetMed home

VetMed is an educational resource, not veterinary advice.