New Animal Drugs; Approval of New Animal Drug Applications; Withdrawal of Approval of New Animal Drug Application; Change of Sponsor; Change of Sponsor Address
The Food and Drug Administration (FDA or we) is amending the animal drug regulations to reflect application-related actions for new animal drug applications (NADAs), abbreviated...
The Food and Drug Administration (FDA or we) is amending the animal drug regulations to reflect application-related actions for new animal drug applications (NADAs), abbreviated new animal drug applications (ANADAs), and conditionally approved new animal drug applications (CNADAs) during July, August, and September 2025. The animal drug regulations are also being amended to improve their accuracy and readability.
DATES:
This rule is effective February 6, 2026.
FOR FURTHER INFORMATION CONTACT:
Cathie Marshall, Center for Veterinary Medicine, Food and Drug Administration, 5001 Campus Dr., College Park, MD 20740,
cathie.marshall@fda.hhs.gov,
240-402-5693.
SUPPLEMENTARY INFORMATION:
I. Approval of Applications
FDA is amending the animal drug regulations to reflect approval actions for NADAs, ANADAs, and CNADAs during July, August, and September 2025, as listed in table 1. Documentation of environmental review required under the National Environmental Policy Act, summaries of the basis of approval under the Freedom of Information Act (FOIA summaries), and marketing exclusivity and patent information are available at Animal Drugs @FDA:
https://animaldrugsatfda.fda.gov/adafda/views/#/search.
Table 1—Original, Conditional, and Supplemental Applications Approved During July, August, and September 2025
Date of approval
Application
No.
Sponsor
(drug labeler code 1
)
Product name
Effect of the action
21 CFR
sections
July 8, 2025
200-807
Huvepharma EOOD (016592)
MGA (melengestrol acetate Type A medicated article) and EXPERIOR (lubabegron Type A medicated article) and MONOVET (monensin Type A medicated article)
Original approval as a generic copy of NADA 141-590
558.330
July 8, 2025
200-808
Huvepharma EOOD (016592)
MGA (melengestrol acetate Type A medicated article) and EXPERIOR (lubabegron Type A medicated article) and MONOVET (monensin Type A medicated article) and TYLOVET (tylosin phosphate Type A medicated article)
Original approval as a generic copy of NADA 141-591
Elanco US Inc., 450 Elanco Circle, Indianapolis, IN 46211 (drug labeler code 058198) requested that FDA withdraw approval of the NADA listed in table 2 because the product information has been combined with NADA 010-918. No change to the regulatory text is required.
( printed page 5300)
Table 2—Applications for Which Approval Was Voluntarily Withdrawn During July, August, and September 2025
Date of withdrawal of approval
Application
No.
Product name
21 CFR
section
August 02, 20231
011-948
HYGROMIX 2.5 (hygromycin B Type A medicated article)
558.274
1
This withdrawal was not previously published.
III. Changes of Sponsor
The sponsor of the approved applications listed in table 3 has informed FDA that they have transferred ownership of, and all rights and interest in, these applications to another sponsor. The regulations cited in table 3 are amended to reflect these actions.
Table 3—Applications for Which Ownership Was Transferred to Another Sponsor During July, August, and September 2025
Application No.
Product name
Transferring sponsor
(drug labeler code)
New sponsor
(drug labeler code)
21 CFR
section
141-136
BIO-COX (salinomycin sodium Type A medicated article) and BMD (bacitracin methylenedisalicylate Type A medicated article)
Zoetis Inc. (054771)
Phibro Animal Health Corp. (066104)
558.550
091-749
TYLAN 10 SULFA-G and TYLAN 40 SULFA-G (tylosin phosphate Type A medicated article and sulfamethazine Type A medicated article)
Do
Do
558.630
IV. Legal Authority
This final rule is issued under section 512(i) of the Federal Food, Drug, and Cosmetic Act (FD&C Act) (21 U.S.C. 360b(i)). Although deemed a rule under the FD&C Act, this document does not meet the definition of “rule” in 5 U.S.C. 804(3)(A) because it is a “rule of particular applicability” and is not subject to the congressional review requirements in 5 U.S.C. 801-808. Likewise, this is not a rule subject to Executive Order 12866.
Therefore, under the Federal Food, Drug, and Cosmetic Act and under authority delegated to the Commissioner of Food and Drugs, 21 CFR parts 516, 520, 522, 529, 556, and 558 are amended as follows:
PART 516—NEW ANIMAL DRUGS FOR MINOR USE AND MINOR SPECIES
1. The authority citation for part 516 continues to read as follows:
(a)
Specifications.
Each milliliter of solution contains 10 milligrams of doramectin.
(b)
Sponsor.
See No. 054771 in § 510.600(c) of this chapter.
(c)
Conditions of use in cattle
—(1)
Amount.
200 micrograms per kilogram (10 milligrams per 110 pounds).
(2)
Indications for use.
For prevention and treatment of infestations caused by larvae of
Cochliomyia hominivorax
(myiasis), and prevention of reinfestation for 21 days in cattle.
(3)
Limitations.
Consult your veterinarian for assistance in the diagnosis, treatment, and control of parasitism. Administer as a single subcutaneous or intramuscular injection. Do not slaughter cattle for human consumption within 35 days of treatment. Not for use in female dairy cattle 20 months of age or older. A withdrawal period has not been established for this product in preruminating calves. Do not use in calves to be processed for veal.
PART 520—ORAL DOSAGE FORM NEW ANIMAL DRUGS
3. The authority citation for part 520 continues to read as follows:
(a)
Specifications.
Each milliliter (mL) of solution contains 10 milligrams (mg) fluralaner.
(b)
Sponsor.
See No. 000061 in § 510.600(c) of this chapter.
(c)
Conditions of use in laying hens and replacement chickens
—(1)
Amount.
Administer orally to chickens via the drinking water as 2 single doses, spaced 7 days apart, with each dose consumed over a period of 6 to 24 hours. Each dose is 0.5 mg fluralaner/kilogram (kg) (0.227 mg/pound (mg/lb)) body weight, equivalent to 0.05 mL fluralaner oral solution/kg body weight (0.023 mL/lb).
(2)
Indications for use.
For the treatment and control of northern fowl mites (
Ornithonyssus sylviarum).
(3)
Limitations.
Federal law restricts this drug to use by or on the order of a licensed veterinarian. Chickens must not be slaughtered for human consumption for 11 days after the last treatment. No egg discard is required when used according to the labeling.
(a)
Specifications.
The product is supplied in two vials, one vial containing 2.51 grams of sterile fluralaner and one vial containing the required 15 milliliters (mL) of sterile vehicle for constitution. Each mL of constituted suspension contains 150 milligrams (mg) fluralaner.
(b)
Sponsor.
See No. 000061 in § 510.600(c) of this chapter.
(c)
Conditions of use—
(1)
Amount.
Administer as a single subcutaneous dose every 12 months or every 8 months in the case of potential exposure to
Amblyomma americanum
ticks. The subcutaneous dose volume is 0.1 mL of the constituted suspension/kilogram (kg) body weight (0.045 mL per pound (mL/lb)). This volume provides a dose of 15 mg fluralaner per kilogram body weight (6.8 mg/lb).
(2)
Indications for use.
Kills adult fleas and for the treatment and prevention of flea infestations (
Ctenocephalides felis); for the treatment and control of tick infestations
Ixodes scapularis
(black-legged tick),
Dermacentor variabilis
(American dog tick), and
Rhipicephalus sanguineus
(brown dog tick) for 12 months in dogs and puppies 6 months of age and older; and for the treatment and control of
Amblyomma americanum
(lone star tick) infestations for 8 months in dogs and puppies 6 months of age and older.
(3)
Limitations.
Federal law restricts this drug to use by or on the order of a licensed veterinarian.
(A) For increased rate of weight gain and improved feed efficiency in growing beef steers and heifers fed in confinement for slaughter.
(B) For increased rate of weight gain in beef calves 2 months of age or older, in growing beef steers and heifers on pasture (stocker, feeder, and slaughter), and in growing beef steers and heifers in a dry lot.
* * * * *
PART 529—CERTAIN OTHER DOSAGE FORM NEW ANIMAL DRUGS
14. The authority citation for part 529 continues to read as follows:
15. In § 529.1186, in paragraph (b), remove the text “See Nos. 017033, 054771, and 065085” and in its place add the text “See Nos. 017033, 054771, 065085, and 068504”.
PART 556—TOLERANCES FOR RESIDUES OF NEW ANIMAL DRUGS IN FOOD
16. The authority citation for part 556 continues to read as follows:
Monensin, 10 to 40 and melengestrol acetate, 0.25 to 2
Growing beef heifers fed in confinement for slaughter: For increased rate of weight gain, improved feed efficiency, suppression of estrus (heat), for reduction of ammonia gas emissions per pound of live weight and hot carcass weight, and for the prevention and control of coccidiosis caused by
Eimeria bovis
and
Eimeria zuernii
during the last 14 to 91 days on feed
Melengestrol acetate Type C top-dress medicated feed (0.5 to 2 lb(s) per head per day) must be top dressed onto or mixed at feeding with a Type C medicated feed containing 1.25 to 4.54 g/ton lubabegron and 10 to 40 g/ton monensin, to provide 0.25 to 0.5 mg melengestrol acetate and 13 to 90 mg lubabegron per head per day, and 0.14 to 0.42 mg monensin per pound of body weight per day, depending upon severity of challenge, up to a maximum of 480 mg monensin per head per day. Feed as the sole ration during the last 14 to 91 days on feed. See special labeling considerations in paragraph (d) of this section, and in §§ 558.342(d) and 558.355(d). Lubabegron fumarate as provided by No. 058198; monensin as provided by No. 058198 or 016592; melengestrol acetate as provided by No. 054771 in § 510.600(c) of this chapter
058198
016592
* * * * *
20. In § 558.550, revise paragraphs (e)(1)(ii) through (iv) to read as follows:
Bacitracin (as feed grade bacitracin methylenedisalicylate) 4 to 50
Broiler chickens and replacement chickens. Not for use in laying hens: For the prevention of coccidiosis caused by
Eimeria tenella, E. necatrix, E. acervulina, E. maxima, E. brunetti,
and
E. mivati,
and for increased rate of weight gain and improved feed efficiency
Feed continuously as sole ration. Discontinue use prior to sexual maturity. The dosage of salinomycin sodium should be adjusted to meet the severity of the coccidial challenge, which varies with environmental and management conditions. May be fatal if fed to adult turkeys or horses. Salinomycin as provided by No. 016592; bacitracin methylenedisalicylate as provided by No. 066104 in § 510.600(c) of this chapter
Broiler chickens and replacement chickens. Not for use in laying hens: For the prevention of coccidiosis caused by
Eimeria tenella, E. necatrix, E. acervulina, E. maxima, E. brunetti,
and
E. mivati,
and as an aid in the prevention of necrotic enteritis caused or complicated by
Clostridium
spp. or other organisms susceptible to bacitracin methylenedisalicylate
Feed continuously as sole ration. Discontinue use prior to sexual maturity. The dosage of salinomycin sodium should be adjusted to meet the severity of the coccidial challenge, which varies with environmental and management conditions. May be fatal if fed to adult turkeys or horses. Salinomycin as provided by No. 016592; bacitracin methylenedisalicylate as provided by No. 066104 in § 510.600(c) of this chapter
066104
(iv) 40 to 60
Bacitracin (as feed grade bacitracin methylenedisalicylate) 100 to 200
Broiler chickens and replacement chickens. Not for use in laying hens: For the prevention of coccidiosis caused by
Eimeria tenella, E. necatrix, E. acervulina, E. maxima, E. brunetti,
and
E. mivati,
and as an aid in the control of necrotic enteritis caused or complicated by
Clostridium
spp. or other organisms susceptible to bacitracin methylenedisalicylate
Feed continuously as the sole ration. Discontinue use prior to sexual maturity. The dosage of salinomycin sodium should be adjusted to meet the severity of the coccidial challenge, which varies with environmental and management conditions. To control a necrotic enteritis outbreak, start medication at the first clinical signs of disease. The bacitracin methylenedisalicylate dosage range permitted provides for different levels based on severity of the infection. Consult a poultry diagnostic laboratory or pathologist to determine the diagnosis and advice regarding the optimal level of bacitracin methylenedisalicylate. Administer continuously for 5-7 days or as long as clinical signs persist, and then reduce bacitracin methylenedisalicylate dosage to prevention level (50 g/ton). May be fatal if fed to adult turkeys or to horses. Salinomycin as provided by No. 016592; bacitracin methylenedisalicylate as provided by No. 066104 in § 510.600(c) in this chapter
066104
* * * * * * *
* * * * *
( printed page 5303)
21. In § 558.625, revise paragraph (e)(2)(ix) to read as follows:
Monensin, 10 to 40 plus lubabegron (as lubabegron fumarate), 1.25 to 4.54, plus melengestrol acetate, 0.25 to 2.0
Growing beef heifers fed in confinement for slaughter: For increased rate of weight gain, improved feed efficiency, suppression of estrus (heat), for reduction of ammonia gas emissions per pound of live weight and hot carcass weight, for the prevention and control of coccidiosis caused by
Eimeria bovis
and
Eimeria zuernii,
and for reduction of incidence of liver abscesses associated with
Fusobacterium necrophorum
and
Arcanobacterium pyogenes
during the last 14 to 91 days on feed
Feed as the sole ration during the last 14 to 91 days on feed. Melengestrol acetate Type C top-dress medicated feed (0.5 to 2.0 lb per head per day) must be top dressed onto or mixed at feeding with a Type C medicated feed containing 8 to 10 g/ton tylosin, 1.25 to 4.54 g/ton lubabegron, and 10 to 40 g/ton monensin, to provide 0.25 to 0.5 mg melengestrol acetate, 60 to 90 mg tylosin per head per day, 13 to 90 mg lubabegron per head per day, and 0.14 to 0.42 mg monensin per pound of body weight per day, depending on severity of challenge, up to 480 mg monensin per head per day. See special labeling considerations in §§ 558.330(d), 558.342(d), and 558.355(d). Tylosin and monensin as provided by No. 058198 or 016592; lubabegron fumarate as provided by No. 058198; melengestrol acetate as provided in No. 054771 in § 510.600(c) of this chapter
Use this for formal legal and research references to the published document.
91 FR 5299
Web Citation
Suggested Web Citation
Use this when citing the archival web version of the document.
“New Animal Drugs; Approval of New Animal Drug Applications; Withdrawal of Approval of New Animal Drug Application; Change of Sponsor; Change of Sponsor Address,” thefederalregister.org (February 6, 2026), https://thefederalregister.org/documents/2026-02331/new-animal-drugs-approval-of-new-animal-drug-applications-withdrawal-of-approval-of-new-animal-drug-application-change-o.