WARNING LETTER

John & Nicole Santos Dairy MARCS-CMS 735859 — October 02, 2026

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 times, or the drug administered. For example, you stated that when no drug was identified on the treatment record, the treatment was (b)(4) (cephapirin sodium) intramammary infusion, NADA (b)(4).
You stated to the FDA investigator you treat heifers (b)(4) with (b)(4) (tulathromycin injection), ANADA (b)(4), without creating any treatment records for the heifers.

Food held under insanitary conditions whereby it may have been rendered injurious to health is adulterated.⁴ The introduction or delivery for introduction into interstate commerce of any food that is adulterated is a prohibited act.⁵

Adulteration of a New Animal Drug

Our inspection found that you did not use drugs as directed by the manufacturer’s approved labeling and your veterinarian’s prescription labels. Use of a drug in a manner that is not consistent with its labeling is an extralabel use.⁶ Specifically,

You administered US Vet brand Ampicillin for Injectable Suspension, ANADA (b)(4), to a dairy cow identified with ear tag (b)(4) on (b)(4), and to a dairy cow identified with ear tag (b)(4) on (b)(4). The drug manufacturer’s labeling and your veterinarian’s prescription labeling require you to hold animals to be offered for slaughter for meat for (b)(4) However, you offered these animals for sale as food on (b)(4), respectively, which was the (b)(4) day after treatment.
You administered (b)(4) (cephapirin sodium) intramammary infusion, NADA (b)(4), without adhering to the labeled withdrawal period before you offered animals for sale for slaughter as food. The drug manufacturer’s labeling states to hold animals to be offered for slaughter for meat “(b)(4),” and your veterinarian’s prescription states to hold animals to be offered for slaughter for meat for (b)(4). However, you treated (b)(4) cows identified with ear tags (b)(4), between (b)(4). You sold these cows on (b)(4), one to two days after treatment.
You did not reconstitute drugs in accordance with labeled directions. Specifically, the labeling for (b)(4) brand Ampicillin for Injectable Suspension, ANADA (b)(4), requires the drug to be reconstituted with (b)(4), and your prescription labeling requires the drug to be reconstituted with 80 mL of sterile water. However, you stated to the FDA investigator that you reconstituted the drug in 100 mL of sterile water when administering to a dairy cow identified with ear tag (b)(4) on (b)(4). Reconstitution of drugs per the labeling is important to administer the proper dosage for the animal’s weight and in accordance with treatment protocols to not use the drug in an extralabel or superpotent manner.

The extralabel uses of the above drugs are only allowed if the use complies with the FD&C Act and 21 CFR Part 530 including that such use must be by or on the lawful order of a licensed veterinarian within the context of a valid veterinarian-client-patient relationship (VCPR).^{7, 8} Your extralabel use of the drugs did not comply with these requirements.

Furthermore, you stated to the FDA investigator that you administered (b)(4) (ceftiofur crystalline free acid) Sterile Suspension, NADA (b)(4), (b)(4) of cows. However, the drug manufacturer labeling and your veterinarian’s prescription required the drug be administered (b)(4). The drug manufacturer labeling also warns, “(b)(4).” Extralabel use of ceftiofur drugs, part of the cephalosporin class of drugs, by unapproved routes of administration is prohibited.⁹ Cephalosporins are medically important antimicrobials critical to treating serious human infections. For this reason, FDA prohibits certain extralabel uses of cephalosporins (at unapproved doses, frequencies, durations, or routes of administration) in major food-producing animal species (cattle, swine, chickens, and turkeys).¹⁰ Such prohibited extralabel uses may contribute to the emergence of antimicrobial-resistant bacteria and may have unknown microbiological or toxicological effects. The improper extralabel use of drugs, especially those prohibited from extralabel use, may result in illegal drug residues remaining in food, such as meat and milk, derived from treated food-producing animals.

Because your use of drugs was not in conformance with approved labeling and did not comply with 21 CFR 530, you caused the drugs to be unsafe and adulterated.¹¹ The doing of any act to a drug after shipment of the drug and/or its components in interstate commerce and while the drug is held for sale (whether or not the first sale) that results in the drug being adulterated is prohibited.¹²

Conclusion

This letter is not intended to be an all-inclusive statement of violations that may exist at your facility or in connection with your products. You are responsible for investigating and determining the causes of any violations and for preventing their recurrence or the occurrence of other violations. It is your responsibility to ensure that you comply with all requirements of federal law and FDA regulations.

This letter notifies you of our concerns and provides you an opportunity to address them. You should take prompt action to correct any violations. Failure to adequately address any violation may lead to regulatory, or where appropriate, legal action.

We have the following comment:

Your records document that you administer (b)(4) (cephapirin sodium) intramammary infusion, NADA (b)(4), on (b)(4) days. However, the drug manufacturer labeling and your veterinarian’s prescription require the drug to be administered (b)(4). We note your treatment records did not document the (b)(4) of the animal treated. Treating any (b)(4) with more than (b)(4) doses is extralabel use.

For more information about FDA’s current thinking on the requirements of safely administering approved drugs to food-producing animals, see:

T.A.L.K. Before You Treat | FDA

Within fifteen (15) working days of receipt of this letter, please notify this office in writing of the specific steps that you have taken to correct any violations. Include an explanation of each step being taken to prevent the recurrence of violations, as well as copies of related documentation. If you cannot complete corrective actions within fifteen (15) working days, state the reason for the delay and the time within which you will complete the correction. If you believe your products are not in violation of the FD&C Act and FDA regulations, include your reasoning and any supporting information for our consideration.

The Food & Drug Administration, Center for Veterinary Medicine, Office of Surveillance and Compliance is encouraging electronic submission of any response you choose to submit to this letter. We encourage you to submit files up to 100 megabytes in a single email, and to divide files greater than 100 megabytes so they may be submitted as smaller files in separate emails. If you submit electronic correspondence, please ensure that your facility’s name, the CMS number at the top of this letter, and the inspection location are included in your correspondence. We intend to issue an electronic acknowledgement upon receipt of your email.

Please direct your electronic correspondence to Compliance Officer Andrew J. Howard at Andrew.Howard@fda.hhs.gov. If you have questions regarding this letter, please contact Compliance Officer Andrew J. Howard by telephone at (410) 779-5125, or by the email listed above.

/S/

Isaac K. Carney
Director of Food Compliance, Office of Animal Foods
Center for Veterinary Medicine
U.S. Food and Drug Administration

Cc:
(b)(6), (b)(7)(C)

Janet McGinn, Director
Food and Drug Administration
Human Food Program Office of Dairy and Seafood Safety
Division of Dairy Safety
Janet.McGinn@fda.hhs.gov

(b)(6), (b)(7)(C)

_______________________

1 See Title 21 Code of Federal Regulations 556.40 (21 CFR 556.40).

2 See Section 402(a)(2)(C)(ii) of the Federal Food, Drug, and Cosmetic Act (FD&C Act) [21 U.S.C. § 342(a)(2)(C)(ii)].

3 See Section 512(a)(4)(B) of the FD&C Act [21 U.S.C. § 360b(a)(4)(B)].

4 See Section 402(a)(4) of the FD&C Act [21 U.S.C. § 342(a)(4)].

5 See Section 301(a) of the FD&C Act [21 U.S.C. § 331(a)].

6 See 21 CFR 530.3(a).

7 See Sections 512(a)(4) and (5) of the FD&C Act [21 U.S.C. § 360b(a)(4) and (5)].

8 See 21 CFR 530.3(i)(1).

9 See 21 CFR 530.41(a)(13).

10 See the Animal Medicinal Drug Use Clarification Act (AMDUCA) and its implementing regulations at 21 CFR Part 530.

11 Under Section 501(a)(5) of the FD&C Act [21 U.S.C. § 351(a)(5)], a new animal drug is deemed adulterated if it is unsafe within the meaning of section 512 of the FD&C Act [21 U.S.C. § 360b].

12 See Section 301(k) of the FD&C Act [21 U.S.C. § 331(k)].