John & Nicole Santos Dairy — FDA Warning Letter, 2026-10-02: New Animal Drug/Adulterated
Letter issued · posted to fda.gov .
Subject as published: New Animal Drug/Adulterated
TL;DR
Here's the summary: The FDA's Center for Veterinary Medicine issued a warning letter (CMS #735859, October 2, 2026) to John & Nicole Santos Dairy in Hilmar, California, following an inspection from May 19–June 16, 2026. The FDA found the dairy sold cattle for slaughter with ampicillin residues exceeding the established 0.01 ppm tolerance (detected at 0.0118 ppm and 0.0288 ppm in kidney tissue), violated drug withdrawal periods by offering treated animals for sale prematurely, failed to maintain complete treatment records, and reconstituted ampicillin in incorrect volumes, violating FD&C Act requirements for animal drug use and food adulteration standards. The dairy did not respond to the FDA 483 Inspectional Observations issued at the inspection's close.
Argus analysis
# FDA Warning Letter Analysis: John & Nicole Santos Dairy
**The Company and Violations**
John & Nicole Santos Dairy, a California-based operation, received a warning letter from the FDA's Center for Veterinary Medicine on October 2, 2026, following an inspection conducted May 19–June 16, 2026. The FDA documented two critical violations: the sale of dairy cattle for slaughter containing antibiotic residues in edible tissue that exceeded established safety tolerances, and systematic failures in drug administration practices. Specifically, two cows sold for human consumption contained ampicillin residues at 0.0118 ppm and 0.0288 ppm in kidney tissue, exceeding the FDA tolerance of 0.01 ppm.
**Regulatory Citations and Meaning**
The violations cite the Federal Food, Drug, and Cosmetic Act and multiple sections of 21 CFR. Section 21 CFR Part 530 governs extralabel drug use in animals and requires compliance with valid veterinarian-client-patient relationships. The warnings reference prohibited extralabel use of cephalosporins—medically important antimicrobials in the cephalosporin class—reflecting FDA concern about antimicrobial resistance. Core violations involve incomplete treatment records (missing dosages, withdrawal times, and conditions treated), failure to observe manufacturer-specified withdrawal periods before slaughter, improper drug reconstitution, and unapproved routes of drug administration. These violations render both the food and drugs "adulterated" under FD&C Act standards.
**Response Timeline and Industry Implications**
The Santos operation has 15 working days to submit corrective actions in writing. Compliance officers in dairy operations should monitor for increased FDA scrutiny of withdrawal period documentation and record-keeping systems. The emphasis on cephalosporin restrictions signals FDA's priority around antimicrobial stewardship in food animal agriculture. Peers should expect potential follow-up inspections and should audit their own treatment records, veterinary protocols, and slaughter-timing procedures for similar gaps.
Severity context
High severity. Typically QSR / device CGMP, adulterated-drug, or significant labeling matters — usually drives a documented corrective and preventive action (CAPA) program.
Regulatory background
FDA Warning Letters are administratively non-binding but signal that recurring non-compliance may escalate to injunction, seizure, import alert, or Application Integrity Policy invocation.
What peer compliance teams typically do next
Most compliance officers at peer companies use a Warning Letter against a named entity as a checklist for their own CAPA program. Common steps: pull the verbatim FDA letter; map each cited 21 CFR section against the team’s SOP library; confirm CAPA coverage; brief the QMR (Quality Management Review) on whether the cited subject matter is in scope for the next internal audit. The 15-business-day response window applies to the cited entity, not to peers — but a documented internal review against the cited subjects is what regulators expect to see if a peer is later inspected on the same topic.
Excerpt from the FDA Warning Letter (public domain, 17 USC §105)
WARNING LETTER John & Nicole Santos Dairy MARCS-CMS 735859 — October 02, 2026 More Warning Letters Warning Letters About Warning and Close-Out Letters Delivery Method: VIA EMAIL NO HARD COPY TO FOLLOW Product: Animal & Veterinary Drugs Recipient: Recipient Name Joao A. Santos, Owner Recipient Title Nicole Santos, Owner John & Nicole Santos Dairy 18235 American Avenue Hilmar , CA 95324-8305 United States (b)(6), (b)(7)(C) Issuing Office: Center for Veterinary Medicine United States WARNING LETTER CMS # 735859 October 2, 2026 Dear Mr. and Mrs. Santos, The United States Food and Drug Administration (FDA) conducted an inspection of your dairy operation located at 18235 American Avenue, Hilmar, California, from May 19 through June 16, 2026. At the close of the inspection, you were issued a Form FDA 483, Inspectional Observations (FDA 483). We have not received a written response to the FDA 483 as of the date of this letter. This letter notifies you of violations of the Federal Food, Drug, and Cosmetic Act (FD&C Act) that were revealed during the inspection. You can find the FD&C Act and its associated regulations on the internet through links on the FDA’s web page at www.fda.gov. Adulteration of Animals Offered for Human Consumption Our inspection found you offered for sale animals for slaughter as food that were adulterated. Specifically, You sold a dairy cow identified with ear tag (b)(4) on (b)(4) . The cow was slaughtered on (b)(4) , at (b)(4) located in (b)(4) . United States Department of Agriculture/Food Safety and Inspection Service (USDA/FSIS) analysis of tissue samples collected from the animal identified the presence of ampicillin at 0.0118 parts per million (ppm) in kidney tissue. You sold a dairy cow identified with ear tag (b)(4) on (b)(4) . The cow was slaughtered on (b)(4) , at (b)(4) , located in (b)(4) . USDA/FSIS analysis of tissue samples collected from the animal identified the presence of ampicillin at 0.0288 ppm in kidney tissue. FDA has established a tolerance of ampicillin at 0.01 ppm in the edible tissues of cattle. 1 The presence of this drug in the edible tissues of these animals at these levels causes the food to be adulterated. A food is deemed to be adulterated if it bears or contains a new animal drug that is unsafe. 2 A drug is unsafe if it results in any residues that exceed any established safe levels. 3 Additionally, our inspection found that you hold animals under insanitary conditions that are inadequate such that medicated animals bearing potentially harmful drug residues are likely to enter the food supply. Specifically, you do not maintain complete and accurate treatment records for cattle that you medicate: You maintain treatment records on paper and document the date administered and animal identification. However, your treatment records are not complete and accurate because you do not consistently document the condition being treated, dosage administered, individual administering the drug, any withdrawal tim…
Excerpt only. The full verbatim Warning Letter is the source of truth — always read the original before regulatory decisions.
The verbatim FDA Warning Letter is the source of truth. Always read the original before acting on any analysis or summary on this page.
Read the full letter on fda.gov ↗Frequently asked questions
- What is the standard FDA response window for a warning letter?
- FDA warning letters typically require a written response within 15 working days of receipt, outlining the corrective and preventive actions the company will take.
- Has John & Nicole Santos Dairy had FDA enforcement actions before?
- This is the only FDA Warning Letter Argus HQ has on file for John & Nicole Santos Dairy as of 2026-10-13. Argus ingests new FDA enforcement records daily.
- What FDA violations was John & Nicole Santos Dairy cited for?
- The FDA Warning Letter to John & Nicole Santos Dairy (issuing office: Center for Veterinary Medicine) cites: New Animal Drug/Adulterated. Classification: Warning Letter.
- When did FDA issue the warning letter to John & Nicole Santos Dairy?
- FDA issued the letter (MARCS-CMS 735859) on 2026-10-02 and posted it publicly on fda.gov on 2026-10-13.
argus.hq
Don’t find out about the next one six weeks late.
Argus reads every FDA Warning Letter the day it publishes, summarizes it against your watchlist, and lands the ones touching your business in your inbox at 6am ET. Plans from $99/month. Cancel any time.
methodology
The analysis above is produced by Anthropic Claude Haiku 4.5 against the verbatim FDA Warning Letter excerpt and is brand-voice lint-checked before publish. The TL;DR is the same summary that ships in the customer email digest. Severity is auto-classified by Argus from the subject string and letter body using rules documented in lib/ingestion/fda-warning-letters.ts.
Argus HQ is informational only. Summaries and analyses are AI-generated and may contain errors, misclassifications, or omissions. Verify against the FDA source URL above. Argus HQ is not a law firm, accounting firm, or regulatory agency, and provides no legal, accounting, financial, medical, or regulatory advice.
Compiled by Argus HQ Research from FDA primary sources · Reviewed by Andy Gaber, Founder
Cite this record
Reusing this data in reporting or research? Here’s a ready-made citation.
Argus HQ Research (2026). John & Nicole Santos Dairy — FDA Warning Letter, 2026-10-02: New Animal Drug/Adulterated. Digital Empire Holdings LLC. Retrieved from https://argushq.ai/fda/warning-letter/fda-wl-john-and-nicole-santos-dairy-2026-10-02-warning-letter
"John & Nicole Santos Dairy — FDA Warning Letter, 2026-10-02: New Animal Drug/Adulterated." Argus HQ Research, Digital Empire Holdings LLC, 2026, argushq.ai/fda/warning-letter/fda-wl-john-and-nicole-santos-dairy-2026-10-02-warning-letter.
Argus HQ Research. "John & Nicole Santos Dairy — FDA Warning Letter, 2026-10-02: New Animal Drug/Adulterated." Digital Empire Holdings LLC. Accessed October 14, 2026. https://argushq.ai/fda/warning-letter/fda-wl-john-and-nicole-santos-dairy-2026-10-02-warning-letter.
@misc{argushq_argushq_ai_fda_warning_letter_fda_wl_john_and_nicole_santos_dairy_2026_10_02_warning_letter_2026,
title = {John & Nicole Santos Dairy — FDA Warning Letter, 2026-10-02: New Animal Drug/Adulterated},
author = {{Argus HQ Research}},
year = {2026},
publisher = {Digital Empire Holdings LLC},
url = {https://argushq.ai/fda/warning-letter/fda-wl-john-and-nicole-santos-dairy-2026-10-02-warning-letter},
note = {Accessed: October 14, 2026}
}