Breed · Cattle
Hereford cattle: adverse event reports
FDA breed label "Hereford cattle" · single-breed animals only
329 adverse event reports received by FDA describe an animal recorded as Hereford cattle (FDA breed label "Hereford cattle"). That is 1.1% of all reports about cattle. Crossbred animals are not counted here, only reports that give this single breed.
5 reports arrived in the 12 months to March 2026, down 17% from 6 in the 12 months before. A breed's count mostly mirrors how common the breed is; registration and ownership figures by breed are not public data, so no per-animal rate can be given.
By active ingredient, the drugs named most often are doramectin, ivermectin and oxytetracycline. Doramectin is named in 10.6% of this breed's reports, about the same share as in reports about all cattle (10.3%).
The terms listed most often are death (34.7%), hypersalivation (8.5%) and anaphylaxis (7.9%). Death appears in 34.7% of reports, about the same share as in all cattle reports (29.4%). 53.8% of reports stating seriousness were classed as serious, against 58.4% for cattle overall.
Drugs named most often, by active ingredient
| Active ingredients recorded for the drug | Reports | Share of Hereford cattle reports | Share of all cattle reports |
|---|---|---|---|
| Doramectin | 35 | 10.6% | 10.3% |
| Ivermectin | 34 | 10.3% | 6.9% |
| Oxytetracycline | 27 | 8.2% | 2.1% |
| Tulathromycin | 21 | 6.4% | 7.3% |
| Eprinomectin | 19 | 5.8% | 4.8% |
| Moxidectin | 19 | 5.8% | 4.2% |
| Progesterone | 16 | 4.9% | 1.5% |
| Dinoprost Tromethamine | 14 | 4.3% | 2.9% |
| Levamisole | 12 | 3.6% | 0.4% |
| Famphur | 11 | 3.3% | 0.4% |
| Monensin | 9 | 2.7% | 10.8% |
| Vitamin E | 7 | 2.1% | 0.8% |
| Enrofloxacin | 6 | 1.8% | 0.7% |
| Flunixin Meglumine | 5 | 1.5% | 0.9% |
| Lincomycin Hydrochloride Monohydrate + Spectinomycin Sulfate Tetrahydrate | 5 | 1.5% | 0.6% |
| Penicillin G Procaine | 5 | 1.5% | 0.6% |
| Albendazole | 4 | 1.2% | 0.9% |
| Ceftiofur Hydrochloride | 4 | 1.2% | 2.1% |
| Clorsulon + Ivermectin | 4 | 1.2% | 1% |
| Florfenicol | 4 | 1.2% | 1.6% |
Ordered by report count. Differences from the species column often come from body size (which drugs a breed is prescribed) and from how common the breed was in the years a drug sold most. FDA states that these data cannot be used to estimate risk or to compare one product with another. Brand and manufacturer names are masked by FDA in these records.
Signs listed in reports
share of Hereford cattle reports listing the termall cattle reports
- Death34.7%114
- Hypersalivation[drooling]8.5%28
- Anaphylaxis[sudden severe allergic-type reaction]7.9%26
- Lack of efficacy (ectoparasite) - lice[the product did not have the expected effect: lice]7.9%26
- Lack of efficacy - NOS[the product did not have the expected effect]7.3%24
- Recumbency[lying down and unable or unwilling to rise]6.7%22
- Injection site swelling[swelling where the injection was given]6.4%21
- Collapse6.1%20
- Dyspnoea[difficulty breathing]6.1%20
- Depression[dull, quiet or withdrawn]4.9%16
- Lack of efficacy (bacteria) - NOS[the product did not have the expected effect: target not specified]4.9%16
- Anorexia[not eating]4.6%15
- Ataxia[unsteady, uncoordinated movement]4.6%15
- Ineffective, estrus synchroniz[legacy FDA term: the product did not have the expected effect (estrus synchroniz)]4%13
- Diarrhoea[diarrhea]3%10
- Pruritus[itching]2.7%9
- Abortion2.4%8
- Eyelid oedema2.4%8
- Facial oedema[swollen face]2.1%7
- Ineffective, worms NOS[legacy FDA term: the product did not have the expected effect (worms nos)]2.1%7
- Trembling2.1%7
- Alopecia NOS[hair loss, type not specified]1.8%6
- Swelling NOS[NOS: not otherwise specified]1.8%6
- Cyanosis[bluish gums or skin from low oxygen]1.5%5
Age and weight
Age of the animal
Weight of the animal
Coloured bar: Hereford cattle reports. Grey bar: all cattle reports.
Trend and outcomes
Reports by month FDA received them. The newest months are incomplete because FDA posts reports with a delay of three to six months.
Outcome recorded in the report
Beside all cattle
| Measure | Hereford cattle | All cattle |
|---|---|---|
| Reports | 329 | 31,229 |
| Latest 12 months | 5 | 644 |
| Classed serious, of reports stating it | 53.8% | 58.4% |
| Death or euthanasia recorded, per 1,000 reports | 398.2 | 368 |
Questions about Hereford cattle reports
How many FDA adverse event reports involve Hereford cattles?
329 reports through March 2026, 1.1% of reports about cattle; 5 in the latest 12 months.
Which drugs are named most often in Hereford cattle reports?
By active ingredient: doramectin (35), ivermectin (34), oxytetracycline (27), tulathromycin (21) and eprinomectin (19). Brands are masked in the public data.
What signs are reported most for this breed?
death (34.7%), hypersalivation (8.5%), anaphylaxis (7.9%), lack of efficacy (ectoparasite) - lice (7.9%) and lack of efficacy - NOS (7.3%).
Is the Hereford cattle more sensitive to certain drugs?
Report counts cannot answer that. They show what was reported, not what a drug did, and they are not adjusted for how many Hereford cattle animals exist or were treated. Breed-related drug sensitivities that are established are described on FDA-approved labels; a veterinarian is the person to ask about an individual animal.
Why are crossbreds not included?
FDA records crossbred animals with one or more component breeds. Counting them under each component would double count, so breed pages use single-breed reports only. Crossbreds remain in the species totals.
How do I report a problem?
Call the drug company using the number on the label, or send Form FDA 1932a to FDA. See the guide on how to report.
Where this comes from. Counts are built from the openFDA Animal & Veterinary adverse event bulk files released 28 Sep 2026, which hold reports FDA's Center for Veterinary Medicine received through 31 Mar 2026. openFDA masks brand and manufacturer names in these files, so drugs are counted by the active ingredients each record discloses and no figure is attributed to a brand, application or company. Ingredient names, and the separate reference lists of approved products, follow the FDA Green Book as of 1 Oct 2026. Breed names are FDA's labels rearranged into everyday order ("Hereford cattle" becomes "Hereford cattle"). No report text, lot numbers or reporter details are published. See the methodology and sources; FDA's record is authoritative, and corrections are handled within five working days.