Cattle dominate food-animal adverse-event reporting in the FDA's veterinary pharmacovigilance database by a wide margin. The 31,093 reports for cattle dwarf the next-largest food-animal species (sheep at 1,069, goats at 831, chickens at 1,062, and turkeys at 519). Together, these reports document the safety and efficacy challenges of medicating the animals that feed the largest segment of US agriculture.

This article analyzes the cattle-specific adverse-event reports in the FDA Center for Veterinary Medicine (CVM) animal drug adverse-event database, covering 1987 through early 2026. Every number below comes from a direct computation of the FDA CVM adverse-event reports (analysis run date: 2026-06-09).

Why cattle pharmacovigilance is different

Cattle drug safety sits at the intersection of animal welfare and human food safety. Three factors distinguish cattle adverse events from companion-animal reports:

1. Death is the dominant reaction. At 29.4% of reports, "Death" is the single most common reaction in cattle — far higher than in dogs (8.1%) or cats. This reflects both the severity of cattle disease presentations (respiratory disease, toxic mastitis, metabolic collapse) and the economic reality that treatment failure in a $1,500–$2,000 animal often ends in mortality rather than referral.
2. Residue and withdrawal violations generate their own reports. "Residues in milk" (4.7%), "Alteration of milk quality" (2.8%), and "Milk production decrease" (2.1%) are food-safety-specific reaction categories that do not exist in companion-animal pharmacovigilance.
3. Efficacy complaints are structured differently. Lack-of-efficacy reports are categorized by organism class — bacteria, ectoparasites (lice), protozoa (coccidia) — reflecting the production-medicine focus on pathogen control rather than symptom management.

Top 20 active ingredients

The list clusters into five functional groups:

• Production technologies: Sometribove (recombinant bovine somatotropin, rbST), melengestrol acetate (estrus suppression), dinoprost (reproductive management), and progesterone (reproductive control) together represent the unique pharmacological tools of production medicine.
• Antiparasitics: Doramectin, ivermectin, monensin, moxidectin, and eprinomectin dominate. These are administered to entire herds, generating high report volume.
• Antibiotics: Tulathromycin, ceftiofur (multiple formulations), tilmicosin, oxytetracycline, cephapirin, and florfenicol represent the respiratory-disease and mastitis treatment arsenal.
• Vaccines: Several bovine respiratory disease combination vaccines appear in the top 20.
• Ionophores: Monensin (appearing as both Monensin Sodium and Monensin) is both an antiparasitic and a production feed additive.

Sometribove (rbST) — the most-reported ingredient

Sometribove (recombinant bovine somatotropin, commercially known as Posilac) leads with 3,262 reports (10.5%). rbST is used to increase milk production in dairy cattle. Its dominant reactions are production-related rather than clinical safety events:

The report volume reflects decades of controversy and intense scrutiny of rbST. Many reports are efficacy-focused or document production changes rather than acute adverse events.

The monensin signal

Monensin — appearing as both Monensin Sodium (1,944) and Monensin (1,395) — generates 3,339 combined reports. Monensin is an ionophore used as a coccidiostat and feed-efficiency additive. It has a notoriously narrow safety margin in non-target species (horses and dogs are highly sensitive to monensin toxicity), and cattle overdoses — often from feed-mixing errors — generate serious adverse events including death.

The FDA has issued safety communications about monensin-related toxicity in horses and dogs exposed to cattle feed, and these cross-species exposure events contribute to the report volume.

Antibiotics and ceftiofur

Ceftiofur — appearing in three formulations (Crystalline Free Acid, Hydrochloride, and unspecified) — collectively generates approximately 2,289 reports. Ceftiofur is a third-generation cephalosporin and one of the most important antibiotics in cattle practice, used for respiratory disease, foot rot, metritis, and mastitis.

The FDA has restricted extralabel use of cephalosporins in food-producing animals since 2012, specifically citing concerns about cephalosporin-resistant bacterial pathogens. Ceftiofur remains approved for cattle, but the restriction reflects the regulatory tension between animal treatment needs and antimicrobial resistance in human medicine.

Tulathromycin (2,201 reports) is a macrolide antibiotic labeled for bovine respiratory disease. Its high report volume reflects the massive scale of bovine respiratory disease complex (BRDC) in feedlot cattle — the single most economically significant disease in the US cattle industry.

Top reactions

The top four reactions account for 55.6% of all cattle reports. Death alone represents nearly a third. Combined, the three lack-of-efficacy categories (bacteria, ectoparasite, NOS) represent 26.2% — documenting treatment failures across the major pathogen classes.

The residue reports (4.7%) are uniquely food-animal. "Residues in milk" documents instances where drug residues exceeded FDA tolerance levels in milk — a direct food-safety concern that triggers regulatory action by the FDA and USDA FSIS. The FDA's Drug Residue Prevention guidelines and the USDA's National Residue Program monitor these events.

Outcomes

The combined Died + Euthanized rate is 36.8% (11,429 unique reports, after deduplicating entries listing both outcomes) — the highest fatality rate of any major species in the database. This is not because cattle drugs are inherently more dangerous; it reflects the severity of cattle disease presentations (shipping fever, toxic mastitis, metabolic emergencies) and the economic constraints on intensive care for food animals.

For comparison, the combined Died + Euthanized rate in dogs is approximately 5.5%, and in horses approximately 14%.

Breed and gender distribution

Holsteins represent the dairy industry — 27.6% of reports from a single breed. Combined with Jerseys (1.9%) and other dairy breeds, dairy cattle likely account for one-third of all reports. This is expected: dairy cattle are individually identified, closely monitored for production metrics (milk yield, somatic cell count), and treated repeatedly over long productive lifespans. Each treatment creates a reporting opportunity.

Angus cattle (8.2%) represent the beef sector. The crossbred and mixed categories (26.2%) likely include feedlot cattle of diverse genetics.

The gender split is 53.3% female, 16.0% male, 18.5% mixed (herd-level reports), and 12.2% unknown. The female dominance reflects the dairy sector, where individual cow treatment events are tracked.

Food-animal species comparison

Cattle represent 90.3% of the five major food-animal species in the database. The disparity reflects several factors: cattle have the largest individual-animal economic value among food species, the most approved drug products, and the most developed identification and tracking infrastructure for adverse events.

Sheep (1,069) and goats (831) are classified as minor species in regulatory terms. Many drugs used in these species are prescribed under the extralabel provisions of AMDUCA (Animal Medicinal Drug Use Clarification Act of 1994), which may reduce formal adverse-event reporting.

Poultry (chicken 1,062, turkey 519) has low individual-animal reporting because poultry operations treat at the flock level, and individual-bird adverse events are rarely captured in the FDA reporting system.

Year-over-year trend

Cattle adverse-event reporting peaked in the mid-2010s and has been declining:

• 2012: 1,167
• 2015: 1,131
• 2017: 1,275
• 2020: 955
• 2023: 725
• 2024: 705
• 2025: 646

The decline may reflect improved product quality, changes in reporting behavior, industry consolidation, or shifts in the cattle population. It coincides with the period during which FDA implemented Guidance for Industry (GFI) #213, which transitioned many medically important antimicrobials from over-the-counter to veterinary-feed-directive (VFD) status in 2017. The increased veterinary oversight under VFD may have improved drug-use practices while changing the reporting dynamics.

What the data means for food-animal practice

The fatality rate is a population-health signal, not a drug-safety score. The 37.3% combined death and euthanasia rate reflects the economics and logistics of cattle medicine. A feedlot heifer with fulminant BRDC may die despite appropriate treatment — the death generates a report, but the cause is disease severity, not drug toxicity.

Residue monitoring and adverse-event reporting overlap. The 4.7% residue-in-milk reporting rate is a food-safety pharmacovigilance metric that has no parallel in companion-animal medicine. Violative residues in meat and milk are tracked by both FDA (drug tolerances under 21 CFR 556) and USDA FSIS (National Residue Program), and the adverse-event database captures some of these events.

Antibiotic efficacy reporting reflects resistance pressure. The 8.7% bacterial lack-of-efficacy rate captures treatment failures that may reflect antimicrobial resistance — a concern that drove the FDA's VFD rule and the ongoing antimicrobial stewardship framework for food-producing animals.

Monensin toxicity is a cross-species risk. Feed-mixing errors that expose horses or dogs to cattle monensin are documented in the adverse-event database. The narrow safety margin of ionophores in non-target species makes this a significant pharmacovigilance concern in mixed-species operations.

Sources

• FDA Center for Veterinary Medicine, Adverse Event Reporting System. openFDA Animal Drug Adverse Event API. Available at: https://open.fda.gov/apis/animalandveterinary/event/
• FDA CVM, "2024 Summary Report on Antimicrobials Sold or Distributed for Use in Food-Producing Animals." Available at: https://www.fda.gov/animal-veterinary/antimicrobial-resistance/2024-summary-report-antimicrobials-sold-or-distributed-use-food-producing-animals
• FDA CVM, "Cephalosporin Order of Prohibition Questions and Answers." Available at: https://www.fda.gov/animal-veterinary/antimicrobial-resistance/cephalosporin-order-prohibition-questions-and-answers
• USDA FSIS, "National Residue Program." Available at: https://www.fsis.usda.gov/policy/food-safety-and-inspection/regulations/residue-chemistry
• Beef Quality Assurance, "Antimicrobial Stewardship for Beef Producers Guidelines (2025)." Available at: https://www.bqa.org/Media/BQA/Docs/bqaantimicrobialstewardshipguidelines2025.pdf
• National Dairy Farm Program, "Drug Residue Prevention Reference Manual (2024–2025)." Available at: https://nationaldairyfarm.com/wp-content/uploads/2024/05/2024-25_MilkDairy_Drug-Residue-Prevention_Manual_DIGITAL.pdf