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Roxee Medication Guide

Levothyroxine

Medication reference facts with explicit FDA-approval, off-label, source-limited, and safety context. Roxee does not sell, prescribe, or dispense medications.

Both Reference complete FDA data linked Rx required Tablet Multiple FDA sponsors Official label facts Owner quick guide first
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Data freshness

Reference facts
Reference refreshed
Jun 22, 2026, 10:41 a.m.

These are the reference facts Roxee uses on browse cards and quick facts.

FDA applications
FDA application data refreshed
Jun 22, 2026, 10:41 a.m.

Sponsor, product, and application records imported from Animal Drugs @ FDA.

Safety reports
Safety data refreshed
Jun 20, 2026, 8:54 p.m.

openFDA reaction terms and case summaries are supporting evidence, not proof of causality.

Source timing details
Source timing details
  • Reference facts: Source Roxee | Refreshed Jun 22, 2026, 10:41 AM UTC
    The reference fact projection used for browse cards and quick facts.
  • Animal Drugs @ FDA: Source FDA | Refreshed Jun 22, 2026, 10:41 AM UTC
    Applications/products are imported from FDA export data.
  • Animal Drugs @ FDA previews: Source FDA | Refreshed Feb 9, 2026, 3:05 AM UTC
    Label highlights/doc links are fetched from FDA preview endpoints.
  • openFDA reaction terms: Source FDA openFDA | Refreshed Jun 22, 2026, 10:45 AM UTC
  • openFDA case summaries: Source FDA openFDA | Refreshed Jun 22, 2026, 10:45 AM UTC
Image coming soon
Levothyroxine

Levothyroxine

Drug type: Generic ingredient • Generic profile • No FDA branded products linked

Both Tablet Rx required 100% reference complete

Species: Both

Manufacturer: Multiple FDA sponsors

Medication Snapshot

Merged from the current Roxee medication system with field-level provenance, freshness, and completeness tracking.

Levothyroxine

For replacement therapy for diminished thyroid function in dogs. Species commonly shown: Both, Dog.

Generic name
Levothyroxine
Brand names
Thyro-Tabs® Canine, ThyroKare™
Manufacturer
Multiple FDA sponsors
Species
Both, Dog
Dosage forms
Tablet
Prescription
Prescription required
Completeness
100%
Validation
Needs review
Brand names
Thyro-Tabs® Canine ThyroKare™
Dosage forms
Tablet

Indications / Uses

For replacement therapy for diminished thyroid function in dogs.

Warnings / Contraindications

For oral use in dogs only. Federal law restricts this drug to use by or on the order of a licensed veterinarian.

  • For oral use in dogs only. Federal law restricts this drug to use by or on the order of a licensed veterinarian.

Side Effects

Top reported reactions (openFDA): Vomiting, Diarrhoea, Lethargy (see also Central nervous system depression in 'Neurological'), Death by euthanasia, Lack of efficacy - NOS, Weight loss.

FAQ

Both, Dog

Yes. Roxee shows this as prescription-only.

Tablet

Source Transparency

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Pet Owner Quick Guide

Start here first for the safest next-step summary before the deeper medication detail.

Used for:

For replacement therapy for diminished thyroid function in dogs.

Dosing note:

Exact dosing depends on your pet's species, weight, and health status. Use your veterinarian's instructions for the exact dose and schedule.

What to watch for:

  • For oral use in dogs only
  • Loss of appetite (1 reports)
  • Intentional misuse (1 reports)
  • Hyperphosphataemia (1 reports)

When to call the vet:

  • Repeated vomiting or diarrhea.
  • Severe lethargy (hard to wake, very low energy).
  • Collapse or fainting.
  • Trouble breathing.
  • Facial swelling or hives.
  • Blood in vomit or stool.

Regulatory restrictions are shown in Vet View.

What to tell or ask your vet today:

  • Is this medicine the right fit for my pet’s current symptoms?
  • Which warning signs mean I should call back right away?
  • How should I handle missed doses or refusal to take the medicine?

Next actions

Talk to a Vet / Find a Vet Near You Save to pet meds Share page Review report evidence
Research brief

Medication Research Insights

A source-aware map of what to know, what is uncertain, and what to verify with your veterinarian.

Source Backed Signals

What to know

Evidence-backed context Limited

Roxee has limited cited overview evidence for Levothyroxine; use the official documents and your veterinarian's instructions for product-specific decisions.

Source: openFDA case USA-USFDACVM-2025-US-069207
Safety signal coverage Reported signals

32 tracked reaction signals; 32 reported cases; 21 serious reports; 2 species groups. These are reporting and label-derived signals for interpretation with a veterinarian.

Source: openFDA case USA-USFDACVM-2025-US-069207
Interpretation guardrail Not causation

Adverse-event reports help form a watch list, but they do not prove the medication caused the reaction and they are not a risk ranking between medications.

Evidence tension

Stronger signal Label / review

Official labels, package inserts, and reviewed summaries carry more weight than isolated reports.

Source: openFDA case USA-USFDACVM-2025-US-069207
Weaker signal Reported data

Case reports and openFDA terms are useful for pattern awareness, but they are incomplete, can include multiple exposures, and do not estimate an individual pet's probability of harm.

Reaction signal map

Most reported reactions Top terms

Loss of appetite (1 reports), Intentional misuse (1 reports), Hyperphosphataemia (1 reports), Hind limb paralysis (1 reports), Hepatomegaly (1 reports)

Body systems represented Signal grouping

Digestive (3), Skin & allergy (1), Neurologic (1), Effectiveness (1)

Explore supporting adverse reports

Species and breed lens

Species represented in reports Species lens

Dog (21 reports), Cat (11 reports)

Breed metadata in reports Metadata only

Retriever - Labrador (1), Siberian Husky (1), Akita (1), Maltese (1). These are report metadata, not proof that a breed is at higher risk.

What your vet may verify

Fit for this patient Vet check

Verify whether Levothyroxine fits the pet's species, current diagnosis, age, weight, organ status, pregnancy/lactation status, and concurrent medications.

Evidence limitations Evidence review

Separate label-backed warnings from adverse-event reports and owner observations before changing the plan.

What to watch next

Watch list Owner-safe

For oral use in dogs only, Loss of appetite, Intentional misuse, Hyperphosphataemia

Call sooner if Escalation

Repeated vomiting or diarrhea. Severe lethargy (hard to wake, very low energy). Collapse or fainting.

Bottom line: Use this Levothyroxine brief as a structured watch list and source map, not as a reason to start, stop, or change treatment without your veterinarian.
Vet source depth
  1. openFDA case USA-USFDACVM-2025-US-069207 · adverse_reaction · adverse reactions
  2. Contraindication source · fda_animal_drugs · warnings contraindications
  3. FDA application profile · official_label · quick facts
  4. FDA application profile · official_label · quick facts
  5. Medication usage source · fda_animal_drugs · quick facts
  6. FOI · document · documents
  7. SPL · document · documents
  8. FOI · document · documents

Evidence

Review status / Updated / Sources

Review status: Clinical reviewer not listed

Updated: April 15, 2026, 10:04 AM UTC

Sources:
Safety & side effects

Side effects to monitor:

  • For oral use in dogs only
  • Loss of appetite
  • Intentional misuse
  • Hyperphosphataemia

Most reported reactions:

  • Loss of appetite (1 reports)
  • Intentional misuse (1 reports)
  • Hyperphosphataemia (1 reports)
Explore reported case details

Emergency warning signs:

  • Repeated vomiting or diarrhea.
  • Severe lethargy (hard to wake, very low energy).
  • Collapse or fainting.
  • Trouble breathing.
Talk to a Vet / Find a Vet Near You Start Symptom Intake

Vet Fast Scan

Source-backed clinical checkpoints for quick review.

FDA-labeled species
Dog
Indication / use
For replacement therapy for diminished thyroid function in dogs.
Form / route / dose
Form: Tablet
Route: Oral
Confirm product label and patient-specific plan.
Warnings
  • High: For oral use in dogs only. Federal law restricts this drug to use by or on the order of a licensed veterinarian.
Adverse-event caveat
openFDA adverse-event cases are reported signals. They are not verified, do not prove causation, and do not estimate a pet's individual risk.
Source docs

Quick Facts

Official label facts first, then secondary summaries. Marketing content is separated below.

Species: Both
Manufacturer: Multiple FDA sponsors
Form: Tablet
Identifiers:
NADA: 141448 NADA: 141539 NDC Package: 11695-6957-1 NDC Package: 11695-6957-2 NDC Package: 11695-6958-1 NDC Package: 11695-6958-2 NDC Package: 11695-6959-1 NDC Package: 11695-6959-2 NDC Package: 11695-6960-1 NDC Package: 11695-6960-2 NDC Package: 11695-6961-1 NDC Package: 11695-6961-2 NDC Package: 11695-6962-1 NDC Package: 11695-6962-2 NDC Package: 11695-6963-1 NDC Package: 11695-6963-2 NDC Package: 11695-6964-1 NDC Package: 11695-6964-2 NDC Package: 11695-6965-1 NDC Package: 11695-6965-2
Source metadata:

Warnings / Contraindications

For oral use in dogs only. Federal law restricts this drug to use by or on the order of a licensed veterinarian.

  • High: For oral use in dogs only. Federal law restricts this drug to use by or on the order of a licensed veterinarian.
Source metadata:

Adverse Reactions

Snapshot first, detailed rows second. This section summarizes signal data and is not a diagnosis.

Reported case explorer

Filter stored openFDA reports by pet and report attributes. Counts describe reports in this data set, not risk.

Clear filters
openFDA adverse-event cases are reported signals. They are not verified, do not prove causation, and do not estimate a pet's individual risk.
Stored reports
7
Matching reports
1
Active filters
1
Selected filters
Body system: Digestive Clear
Reset
Drill into common report signals
Abnormal cytology (2) Ataxia (2) Partial lack of efficacy (2) Alopecia (1) Other (6) Effectiveness (2) Neurologic (2) Digestive (1)
Showing up to 50 matching reports.

USA-USFDACVM-2025-US-071832

Received 2025-12-02 · MSK · MSK

Non-serious
Species
Dog
Breed
['Terrier - Yorkshire', 'Terrier (unspecified)']
Size / weight
10-24 lb (5.321 Kilogram)
Age
8+ years (12 Year)
Sex
Female Unknown
Region
USA
Reactions
DiarrhoeaBloody stool
Body systems
DigestiveOther
Outcomes
Recovered/Normal

Tap or hover a reaction to see what it means in plain language.

Tracked signals
32
Reported cases
32
Serious reports
21
Species represented
2
Grouped by Body System
Digestive (3) · Loss of appetite, Diarrhea, Bloody diarrhoea Skin & allergy (1) · Hair loss Neurologic (1) · Unsteady walking (ataxia) Effectiveness (1) · Lack of efficacy - NOS Other (26) · Intentional misuse, Hypothyroidism, Hyperphosphataemia
Most Reported Reactions
Reaction Body system Cases Species Serious cases
Digestive 1 Dog 1
Other 1 Cat 1
Other 1 Cat 1
Other 1 Dog 1
Other 1 Dog 1
Other 1 Dog 1
Other 1 Cat 1
Other 1 Dog 1

Species coverage: Dog (21) Cat (11)

View detailed reaction table
Reaction Body system Species Seriousness Frequency Reports
Neurologic Dog Non-serious - 1
Digestive Dog Serious - 1
Effectiveness Dog Non-serious - 1
Other Cat Serious - 1
Other Dog Non-serious - 1
Other Cat Serious - 1
Other Dog Serious - 1
Other Dog Serious - 1
Skin & allergy Dog Non-serious - 1
Other Dog Serious - 1
Other Cat Serious - 1
Other Dog Non-serious - 1
Other Dog Non-serious - 1
Other Dog Serious - 1
Other Cat Serious - 1
Other Cat Serious - 1
Other Cat Serious - 1
Other Dog Serious - 1
Digestive Dog Non-serious - 1
Other Cat Serious - 1
Other Dog Serious - 1
Other Dog Serious - 1
Other Dog Non-serious - 1
Other Dog Non-serious - 1
Digestive Dog Non-serious - 1
Other Cat Serious - 1
Other Dog Serious - 1
Other Cat Serious - 1
Other Dog Non-serious - 1
Other Dog Serious - 1
Other Cat Serious - 1
Other Cat Serious - 1
Source metadata:

Source Documents

The most useful source links appear first; full previews and metadata stay in the veterinary/professional layer.

Use original documents to confirm product-specific warnings, ingredients, and handling details with your veterinarian.

ThyroKare™ SPL · SPL Thyro-Tabs® Canine SPL · SPL FOI Summary oN 141-539 Approved January 15, 2021.pdf FOI · FOI

Full source previews and metadata remain in the veterinary/professional layer.

Owner handouts

0
No owner handouts linked yet.

Official label / PI

0
No official label or package insert links yet.

SPL

2

FOI

2

ThyroKare™

SPL · SPL

Open original
FDA Structured Product Label

ThyroKare™

Rendered from Roxee's cached FDA SPL package contents for on-page reading. Use Open original for the raw FDA ZIP/XML source.

Sponsor
Neogen Corp.
NADA
141-539
Status
RX
Form
Tablet
Route
Oral
Species
Dog
Composition / specifications
0.1 mg, 0.2 mg, 0.3 mg, 0.4 mg, 0.5 mg, 0.6 mg, 0.7 mg, 0.8 mg, or 1.0 mg of levothyroxine sodium per tablet

Dogs

Indication

For replacement therapy for diminished thyroid function in dogs.

Dosage

The initial dose is 0.1 mg/10 lb (0.01 mg/lb, 0.022 mg/kg) body weight twice daily.

Thyro-Tabs® Canine

SPL · SPL

Open original
FDA Structured Product Label

Thyro-Tabs® Canine

Rendered from Roxee's cached FDA SPL package contents for on-page reading. Use Open original for the raw FDA ZIP/XML source.

Sponsor
Lloyd, Inc.
NADA
141-448
Status
RX
Form
Tablet
Route
Oral
Species
Dog
Composition / specifications
0.1 mg, 0.2 mg, 0.3 mg, 0.4 mg, 0.5 mg, 0.6 mg, 0.7 mg, 0.8 mg, or 1.0 mg of levothyroxine sodium per tablet

Dogs

Indication
For replacement therapy for diminished thyroid function in dogs.
Dosage
Administer by mouth 0.1 mg/10 pounds of body weight (0.022 mg/kilogram) as a single dose every 24 hours or as a divided dose every 12 hours.
Limitations
For oral use in dogs only. Federal law restricts this drug to use by or on the order of a licensed veterinarian.

FOI Summary oN 141-539 Approved January 15, 2021.pdf

FOI · FOI

Open original

UCM484490.pdf

FOI · FOI

Open original
Source metadata:
Veterinary reference (advanced)

Canonical medication sections are above. This legacy block remains available for deeper cross-reference without cluttering the primary workflow.

At a Glance

Quick facts and links to official labeling and safety signals.

Data freshness
  • Reference facts: Source Roxee | Refreshed Jun 22, 2026, 10:41 AM UTC
    The reference fact projection used for browse cards and quick facts.
  • Animal Drugs @ FDA: Source FDA | Refreshed Jun 22, 2026, 10:41 AM UTC
    Applications/products are imported from FDA export data.
  • Animal Drugs @ FDA previews: Source FDA | Refreshed Feb 9, 2026, 3:05 AM UTC
    Label highlights/doc links are fetched from FDA preview endpoints.
  • openFDA reaction terms: Source FDA openFDA | Refreshed Jun 22, 2026, 10:45 AM UTC
  • openFDA case summaries: Source FDA openFDA | Refreshed Jun 22, 2026, 10:45 AM UTC
Official (FDA)
Identity: Generic ingredient • No FDA branded products linked
No official FDA brand rows linked yet for this ingredient.
Case-reported brands (openFDA): MSK
Catalog species: Both • FDA-labeled species: Dog
Rx/OTC: RX
Form/route: Tablet • Oral
Applications: NADA 141-539 • NADA 141-448
Documents: 2 (FOI: 2) • SPL: 2 • Label highlights • Official documents
Safety (openFDA)
Top reactions: Dog 22 • Cat 11 • View
Case summaries: 7 (showing 7) • View
openFDA reports are unverified and do not prove causation.
Diagnosis Codes

Diagnosis-code mappings are not available for this medication yet.

Counseling and Monitoring Highlights

Global Pet owner/Vet mode is controlled in the header. This section avoids duplicate in-page persona tabs.

Owner-facing counseling points
  • For oral use in dogs only. Federal law restricts this drug to use by or on the order of a licensed veterinarian. (Contraindication, High)
Top reaction signals
Loss of appetite (1) Intentional misuse (1) Hyperphosphataemia (1) Hind limb paralysis (1) Hepatomegaly (1) Gastric ulcer (1) Gait abnormality (1) Elevated thyroxine (1)

Identifiers & Packages

Normalized identifiers (NDC/NADA/ANADA) and package metadata from regulator listings.

Identifiers
NADA: 141448 NADA: 141539 NDC Package: 11695-6957-1 NDC Package: 11695-6957-2 NDC Package: 11695-6958-1 NDC Package: 11695-6958-2 NDC Package: 11695-6959-1 NDC Package: 11695-6959-2 NDC Package: 11695-6960-1 NDC Package: 11695-6960-2 NDC Package: 11695-6961-1 NDC Package: 11695-6961-2 NDC Package: 11695-6962-1 NDC Package: 11695-6962-2 NDC Package: 11695-6963-1 NDC Package: 11695-6963-2 NDC Package: 11695-6964-1 NDC Package: 11695-6964-2 NDC Package: 11695-6965-1 NDC Package: 11695-6965-2 NDC Package: 11695-7014-1 NDC Package: 11695-7014-2 NDC Package: 11789-048-10 NDC Package: 11789-048-20
Package NDC Product NDC Form / Route Status
11695-6957-1 11695 -
11695-6957-2 11695 -
11695-6958-1 11695 -
11695-6958-2 11695 -
11695-6959-1 11695 -
11695-6959-2 11695 -
11695-6960-1 11695 -
11695-6960-2 11695 -
11695-6961-1 11695 -
11695-6961-2 11695 -
11695-6962-1 11695 -
11695-6962-2 11695 -
11695-6963-1 11695 -
11695-6963-2 11695 -
11695-6964-1 11695 -
11695-6964-2 11695 -
11695-6965-1 11695 -
11695-6965-2 11695 -
11695-7014-1 11695 -
11695-7014-2 11695 -

Enriched Documents

Documents are tiered by source trust: Official, Clinical, Manufacturer, Marketing.

Data Sources & Change Log

Every non-trivial field is expected to include provenance and update timestamps.

Official 11 Clinical 8 Manufacturer 0 Marketing 0
Current Field Facts
  • contraindications: For oral use in dogs only. Federal law restricts this drug to use by or on the order of a licensed veterinarian. (Clinical, 2026-04-16)
  • contraindications: For oral use in dogs only. Federal law restricts this drug to use by or on the order of a licensed veterinarian. (Clinical, 2026-04-15)
  • contraindications: For oral use in dogs only. Federal law restricts this drug to use by or on the order of a licensed veterinarian. (Clinical, 2026-04-11)
  • monitoring: Monitor blood glucose and ketones, hydration status, appetite, and clinical response at regular intervals. (Clinical, 2026-04-16)
  • side_effects: Top reported reactions (openFDA): Vomiting, Diarrhoea, Lethargy (see also Central nervous system depression in 'Neurological'), Death by euthanasia, Lack of ef… (Clinical, 2026-04-11)
  • usage: For replacement therapy for diminished thyroid function in dogs. (Clinical, 2026-04-16)
  • usage: For replacement therapy for diminished thyroid function in dogs. (Clinical, 2026-04-15)
  • usage: For replacement therapy for diminished thyroid function in dogs. (Clinical, 2026-04-11)
  • contraindications: For oral use in dogs only. Federal law restricts this drug to use by or on the order of a licensed veterinarian. (Official, 2026-04-22)
  • contraindications: For oral use in dogs only. Federal law restricts this drug to use by or on the order of a licensed veterinarian. (Official, 2026-02-12)
  • side_effects: Top reported reactions (openFDA): Vomiting, Diarrhoea, Lethargy (see also Central nervous system depression in 'Neurological'), Death by euthanasia, Lack of ef… (Official, 2026-04-22)
  • side_effects: Top reported reactions (openFDA): Vomiting, Diarrhoea, Lethargy (see also Central nervous system depression in 'Neurological'), Death by euthanasia, Lack of ef… (Official, 2026-04-16)
  • side_effects: Top reported reactions (openFDA): Vomiting, Diarrhoea, Lethargy (see also Central nervous system depression in 'Neurological'), Death by euthanasia, Lack of ef… (Official, 2026-04-15)
  • side_effects: Top reported reactions (openFDA): Vomiting, Diarrhoea, Lethargy (see also Central nervous system depression in 'Neurological'), Death by euthanasia, Lack of ef… (Official, 2026-02-12)
  • usage: For replacement therapy for diminished thyroid function in dogs. (Official, 2026-04-22)
  • usage: Senvelgo (velagliflozin oral solution) is approved in cats for control of hyperglycemia associated with diabetes mellitus. (Official, 2026-04-16)
  • usage: For replacement therapy for diminished thyroid function in dogs. (Official, 2026-02-12)
Recent Revisions
  • side_effects updated 2026-04-22 10:07 by etl_backfill • Backfilled from existing medication fields
  • contraindications updated 2026-04-22 10:07 by etl_backfill • Backfilled from existing medication fields
  • usage updated 2026-04-22 10:07 by etl_backfill • Backfilled from existing medication fields
  • side_effects updated 2026-04-16 10:08 by etl_backfill • Backfilled from existing medication fields
  • contraindications updated 2026-04-16 10:08 by etl_backfill • Backfilled from existing medication fields
  • usage updated 2026-04-16 10:08 by etl_backfill • Backfilled from existing medication fields
  • monitoring updated 2026-04-16 10:08 by curated_loader • Clinical monitoring context for feline diabetes management.
  • usage updated 2026-04-16 10:08 by curated_loader • Usage statement from FDA warning letter and approved-product context.
  • drug_profile_type updated 2026-04-16 10:08 by curated_loader • FDA source confirms Senvelgo as a branded approved product.
  • manufacturer_name updated 2026-04-16 10:08 by curated_loader • FDA warning letter identifies the approved sponsor/manufacturer.
  • brand_names updated 2026-04-16 10:08 by curated_loader • FDA warning letter references Senvelgo as the approved animal drug.
  • approval_reference updated 2026-04-16 10:08 by curated_loader • Official FDA application reference for Senvelgo.
  • side_effects updated 2026-04-15 10:04 by etl_backfill • Backfilled from existing medication fields
  • contraindications updated 2026-04-15 10:04 by etl_backfill • Backfilled from existing medication fields
  • usage updated 2026-04-15 10:04 by etl_backfill • Backfilled from existing medication fields
  • side_effects updated 2026-04-11 10:05 by etl_backfill • Backfilled from existing medication fields
  • contraindications updated 2026-04-11 10:05 by etl_backfill • Backfilled from existing medication fields
  • usage updated 2026-04-11 10:05 by etl_backfill • Backfilled from existing medication fields
  • side_effects updated 2026-02-12 22:44 by etl_backfill • Backfilled from existing medication fields
  • contraindications updated 2026-02-12 22:44 by etl_backfill • Backfilled from existing medication fields

FDA Products & Applications (Animal Drugs @ FDA)

Official sponsor/proprietary-name/application-status records linked by active ingredient.

Product Sponsor Application Status Published
ThyroKare™
RX
Levothyroxine sodium
Tablet • Oral
Label highlights
Official documents
Neogen Corp. NADA 141-539 Approved Feb 1, 2021
Thyro-Tabs® Canine
RX
Levothyroxine sodium
Tablet • Oral
Label highlights
Official documents
Lloyd, Inc. NADA 141-448 Approved Jun 1, 2016

Data source: FDA Animal Drugs @ FDA (public search export).

What It's For (FDA Label Highlights)

Extracted from FDA Animal Drugs @ FDA product labeling. Always confirm details with your veterinarian.

Species: Dog
Composition / specifications
0.1 mg, 0.2 mg, 0.3 mg, 0.4 mg, 0.5 mg, 0.6 mg, 0.7 mg, 0.8 mg, or 1.0 mg of levothyroxine sodium per tablet
Dogs
Indication

For replacement therapy for diminished thyroid function in dogs.

Dosage

The initial dose is 0.1 mg/10 lb (0.01 mg/lb, 0.022 mg/kg) body weight twice daily.

Limitations

FDA page: Open in Animal Drugs @ FDA

Species: Dog
Composition / specifications
0.1 mg, 0.2 mg, 0.3 mg, 0.4 mg, 0.5 mg, 0.6 mg, 0.7 mg, 0.8 mg, or 1.0 mg of levothyroxine sodium per tablet
Dogs
Indication
For replacement therapy for diminished thyroid function in dogs.
Dosage
Administer by mouth 0.1 mg/10 pounds of body weight (0.022 mg/kilogram) as a single dose every 24 hours or as a divided dose every 12 hours.
Limitations
For oral use in dogs only. Federal law restricts this drug to use by or on the order of a licensed veterinarian.

FDA page: Open in Animal Drugs @ FDA

Usage

For replacement therapy for diminished thyroid function in dogs.

Source: FDA Animal Drugs @ FDA • Reference

Contraindications

For oral use in dogs only. Federal law restricts this drug to use by or on the order of a licensed veterinarian.

Top Reported Reactions (openFDA)

De-duplicated reaction terms grouped by body system from FDA openFDA reports (not verified; does not prove causation).

Digestive
Loss of appetite (1) • Dog Diarrhea (1) • Dog Bloody diarrhoea (1) • Dog

Showing top 5 for Digestive.

Skin & allergy
Hair loss (1) • Dog

Showing top 5 for Skin & allergy.

Neurologic
Unsteady walking (1) • Dog

Showing top 5 for Neurologic.

Effectiveness
Lack of efficacy - NOS (1) • Dog

Showing top 5 for Effectiveness.

Other
Intentional misuse (1) • Cat Hypothyroidism (1) • Dog Hyperphosphataemia (1) • Cat Hind limb paralysis (1) • Dog Hepatomegaly (1) • Dog
Show more (21)
Gastric ulcer (1) • Dog Gait abnormality (1) • Cat Excoriation (1) • Dog Erythema (1) • Dog Elevated thyroxine (1) • Dog Elevated symmetrical dimethylarginine (1) • Cat Elevated creatinine (1) • Cat Elevated creatine-kinase (1) • Cat Elevated cholesterol (1) • Dog Decreased urine concentration (1) • Cat Complication of diabetes (1) • Dog Collapse of leg (1) • Dog Cellulitis (1) • Dog Bloody stool (1) • Dog Blood in urine (1) • Cat Blood in faeces (1) • Dog Blindness (1) • Cat Bacterial skin infection NOS (1) • Dog Anaemia NOS (1) • Dog Acute renal failure (1) • Cat Abnormal cytology (1) • Cat

Showing top 5 for Other.

Data source: FDA openFDA Animal & Veterinary adverse event reports.

Adverse Event Case Summaries (openFDA)

These are individual FDA adverse event reports. They are unverified and do not prove the medication caused the reaction.

Dog, Retriever - Labrador, Female, 9 year, 47.446 kilogram • Drug: MSK, Unassigned, Unknown • Reactions: Unsteady walking (ataxia) • Outcome: Recovered/Normal

  • Report ID: USA-USFDACVM-2025-US-075417
  • Serious AE: No
  • Treated For AE: No
  • Sex: Female
  • Age: 9.00 Year
  • Weight: 47.446 Kilogram
  • Case-reported brand: MSK
  • Case-reported manufacturer: MSK
  • Route: Unknown
  • Form: Unassigned
Reactions Reported:
Unsteady walking (ataxia)
Outcomes: Recovered/Normal

Dog, Siberian Husky, Male, 11 year, 30.16 kilogram • Drug: MSK, Unassigned, Unknown • Reactions: Polyuria, Polydipsia, Skin discolouration NOS, Poor coat condition, Complication of diabetes… • Outcome: Ongoing

  • Report ID: USA-USFDACVM-2025-US-074352
  • Serious AE: Yes
  • Treated For AE: Yes
  • Sex: Male
  • Age: 11.00 Year
  • Weight: 30.160 Kilogram
  • Case-reported brand: MSK
  • Case-reported manufacturer: MSK
  • Route: Unknown
  • Form: Unassigned
Reactions Reported:
Polyuria Polydipsia Skin discolouration NOS Poor coat condition Complication of diabetes Elevated thyroxine Elevated cholesterol Partial lack of efficacy Weight gain
Outcomes: Ongoing

Dog, Akita, Female, 6 year, 52.617 kilogram • Drug: MSK, Unassigned, Oral • Reactions: Collapse of leg, Hind limb paralysis • Outcome: Recovered/Normal

  • Report ID: USA-USFDACVM-2025-US-071706
  • Serious AE: Yes
  • Treated For AE: No
  • Sex: Female
  • Age: 6.00 Year
  • Weight: 52.617 Kilogram
  • Case-reported brand: MSK
  • Case-reported manufacturer: MSK
  • Route: Oral
  • Form: Unassigned
Reactions Reported:
Collapse of leg Hind limb paralysis
Outcomes: Recovered/Normal

Dog, Maltese, Male, 12 year, 4.9 kilogram • Drug: MSK, Oral • Reactions: Loss of hearing • Outcome: Ongoing

  • Report ID: USA-USFDACVM-2025-US-071474
  • Serious AE: Yes
  • Treated For AE: Yes
  • Sex: Male
  • Age: 12.00 Year
  • Weight: 4.900 Kilogram
  • Case-reported brand: MSK
  • Case-reported manufacturer: MSK
  • Route: Oral
Reactions Reported:
Loss of hearing
Outcomes: Ongoing

Dog, ['Terrier - Yorkshire', 'Terrier (unspecified)'], Female, 12 year, 5.321 kilogram • Drug: MSK, Unassigned, Oral • Reactions: Diarrhea, Bloody stool • Outcome: Recovered/Normal

  • Report ID: USA-USFDACVM-2025-US-071832
  • Serious AE: No
  • Treated For AE: No
  • Sex: Female
  • Age: 12.00 Year
  • Weight: 5.321 Kilogram
  • Case-reported brand: MSK
  • Case-reported manufacturer: MSK
  • Route: Oral
  • Form: Unassigned
Reactions Reported:
Diarrhea Bloody stool
Outcomes: Recovered/Normal

Dog, Terrier - Yorkshire, Female, 13 year, 6.12 kilogram • Drug: MSK, Unknown • Reactions: Partial lack of efficacy, Hair loss, Erythema, Papule, Excoriation… • Outcome: Ongoing

  • Report ID: USA-USFDACVM-2025-US-072174
  • Serious AE: No
  • Treated For AE: Yes
  • Sex: Female
  • Age: 13.00 Year
  • Weight: 6.120 Kilogram
  • Case-reported brand: MSK
  • Case-reported manufacturer: MSK
  • Route: Unknown
Reactions Reported:
Partial lack of efficacy Hair loss Erythema Papule Excoriation Skin scab Bacterial skin infection NOS Abnormal cytology
Outcomes: Ongoing

Cat, Domestic Shorthair, Female, 13 year, 5.5 kilogram • Drug: MSK, Unassigned, Unknown • Reactions: Elevated creatine-kinase, Unsteady walking (ataxia), Stiffness limb, Unable to stand, Not eating… • Outcome: Ongoing

  • Report ID: USA-USFDACVM-2025-US-069207
  • Serious AE: Yes
  • Treated For AE: Yes
  • Sex: Female
  • Age: 13.00 Year
  • Weight: 5.500 Kilogram
  • Case-reported brand: MSK
  • Case-reported manufacturer: MSK
  • Route: Unknown
  • Form: Unassigned
Reactions Reported:
Elevated creatine-kinase Unsteady walking (ataxia) Stiffness limb Unable to stand Not eating Weight loss Tiredness (lethargy) Lying down Uncomfortable Abnormal cytology Intentional misuse
Outcomes: Ongoing

Data source: FDA openFDA Animal & Veterinary adverse event reports.

Overdose Information

No approved overdose-management text is linked yet. If overdose is suspected, contact a veterinarian or emergency clinic immediately.

Storage & Handling

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