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Roxee Medication Guide

Spinosad

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 (Chewable) Elanco US Inc. 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 6, 2026, 10:02 a.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, 10:40 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.
  • Animal Drug Product Listing Directory (NDC): Source FDA | Refreshed Jun 22, 2026, 10:41 AM UTC
    Package/product NDCs from FDA’s electronic listing directory (XLS).
  • 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
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Spinosad

Spinosad

Drug type: Generic ingredient • Branded profile FDA branded products available

Both Tablet (Chewable) Rx required 100% reference complete

Species: Both

Manufacturer: Elanco US Inc.

Medication Snapshot

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

Spinosad

To kill fleas and for the prevention and treatment of flea infestations ( Ctenocephalides felis ) for 1 month on dogs and puppies 14 weeks of age and older and 5.0 pounds or body weight or greater. To kill fleas and for the prevention and treatment of flea infestations ( Ctenocephalides felis ) for 1 month on cats and kittens 14 weeks of age and older and 4.1 pounds of body weight or greater. Trifexis™ Chewable Tablets kill fleas and are indicated for the prevention and treatment of flea infestations ( Ctenocephalides felis ), and the treatment and control of adult hookworm ( Ancylostoma caninum ), adult roundworm ( Toxocara canis and Toxascaris leonina ) and adult whipworm ( Trichuris vulpis ) infections in dogs and puppies 8 weeks of age or older and 5 pounds of body weight or greater. Species commonly shown: Both, Dog, Cat.

Generic name
Spinosad
Brand names
Comfortis®, Comfortis
Manufacturer
Elanco US Inc.
Species
Both, Dog, Cat
Dosage forms
Tablet (Chewable)
Prescription
Prescription required
Completeness
100%
Validation
Complete
Brand names
Comfortis® Comfortis
Dosage forms
Tablet (Chewable)

Indications / Uses

To kill fleas and for the prevention and treatment of flea infestations ( Ctenocephalides felis ) for 1 month on dogs and puppies 14 weeks of age and older and 5.0 pounds or body weight or greater. To kill fleas and for the prevention and treatment of flea infestations ( Ctenocephalides felis ) for 1 month on cats and kittens 14 weeks of age and older and 4.1 pounds of body weight or greater. Trifexis™ Chewable Tablets kill fleas and are indicated for the prevention and treatment of flea infestations ( Ctenocephalides felis ), and the treatment and control of adult hookworm ( Ancylostoma caninum ), adult roundworm ( Toxocara canis and Toxascaris leonina ) and adult whipworm ( Trichuris vulpis ) infections in dogs and puppies 8 weeks of age or older and 5 pounds of body weight or greater.

Warnings / Contraindications

Federal law restricts this drug to use by or on the order of a licensed veterinarian. Federal (USA) law restricts this drug to use by or on the order of a licensed veterinarian. Treatment with fewer than 3 monthly doses after the last exposure to mosquitos may not provide complete heartworm prevention. Use with caution in breeding females. The safe use of TRIFEXIS in breeding males has not been evaluated. Use with caution in dogs with pre-existing epilepsy.

  • Federal law restricts this drug to use by or on the order of a licensed veterinarian. Federal (USA) law restricts this drug to use by or on the order of a licensed veterinarian. Treatment with fewer than 3 monthly doses after the last exposure to mosquitos may not provide complete heartworm prevention. Use with caution in breeding females. The safe use of TRIFEXIS in breeding males has not been evaluated. Use with caution in dogs with pre-existing epilepsy.

Side Effects

Top reported reactions (openFDA): Vomiting, Lethargy (see also Central nervous system depression in 'Neurological'), Lack of efficacy (endoparasite) - heartworm, Lack of efficacy (ectoparasite) - flea, Diarrhoea, Lack of efficacy (flea).

FAQ

Both, Dog, Cat

Yes. Roxee shows this as prescription-only.

Tablet (Chewable)

Related Conditions

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:

To kill fleas and for the prevention and treatment of flea infestations ( Ctenocephalides felis ) for 1 month on dogs and puppies 14 weeks of age and older and 5.0 pounds or body weight or greater.

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:

  • Federal (USA) law restricts this drug to use by or on the order of a licensed veterinarian
  • Treatment with fewer than 3 monthly doses after the last exposure to mosquitos may not provide complete heartworm prevention
  • Use with caution in breeding females
  • The safe use of TRIFEXIS in breeding males has not been evaluated
  • Use with caution in dogs with pre-existing epilepsy
  • Skin scab (1 reports)
  • Seizure NOS (1 reports)
  • Generalised itching (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

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 Spinosad; use the official documents and your veterinarian's instructions for product-specific decisions.

Source: openFDA case USA-USFDACVM-2025-US-074182
Safety signal coverage Reported signals

30 tracked reaction signals; 28 reported cases; 5 serious reports; 2 species groups. These are reporting and label-derived signals for interpretation with a veterinarian.

Source: openFDA case USA-USFDACVM-2025-US-074182
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-074182
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

Skin scab (1 reports), Seizure NOS (1 reports), Generalised itching (1 reports), Death (1 reports), Biting - pruritus (1 reports)

Body systems represented Signal grouping

Digestive (1), Skin & allergy (5), Neurologic (2), Behavior (1)

Explore supporting adverse reports

Species and breed lens

Species represented in reports Species lens

Dog (21 reports), Cat (9 reports)

Breed metadata in reports Metadata only

Domestic Shorthair (2), Poodle - Miniature (1), ['Poodle - Miniature', 'Dog (unknown)'] (1), ['Terrier (unspecified)', 'Spaniel (unspecified)'] (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 Spinosad 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

Federal (USA) law restricts this drug to use by or on the order of a licensed veterinarian, Treatment with fewer than 3 monthly doses after the last exposure to mosquitos may not provide compl, Use with caution in breeding females, The safe use of TRIFEXIS in breeding males has not been evaluated, Use with caution in dogs with pre-existing epilepsy

Call sooner if Escalation

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

Bottom line: Use this Spinosad 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-074182 · adverse_reaction · adverse reactions
  2. Contraindication source · fda_animal_drugs · warnings contraindications
  3. FDA application profile · official_label · quick facts
  4. Medication usage source · fda_animal_drugs · quick facts
  5. FOI · document · documents
  6. FOI · document · documents
  7. Labeling · document · documents
  8. SPL · document · documents

Evidence

Review status / Updated / Sources

Review status: Clinical reviewer not listed

Updated: February 12, 2026, 10:44 PM UTC

Sources:
Safety & side effects

Side effects to monitor:

  • Federal (USA) law restricts this drug to use by or on the order of a licensed veterinarian
  • Treatment with fewer than 3 monthly doses after the last exposure to mosquitos may not provide complete heartworm prevention
  • Use with caution in breeding females
  • The safe use of TRIFEXIS in breeding males has not been evaluated
  • Use with caution in dogs with pre-existing epilepsy

Most reported reactions:

  • Skin scab (1 reports)
  • Seizure NOS (1 reports)
  • Generalised itching (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.

Vet Fast Scan

Source-backed clinical checkpoints for quick review.

FDA-labeled species
Cat, Dog
Indication / use
To kill fleas and for the prevention and treatment of flea infestations ( Ctenocephalides felis ) for 1 month on dogs and puppies 14 weeks of age and older and 5.0 pounds or body …
Form / route / dose
Form: Tablet (Chewable)
Route: Oral
Confirm product label and patient-specific plan.
Warnings
  • High: Federal law restricts this drug to use by or on the order of a licensed veterinarian. Federal (USA) law restricts this …
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: Elanco US Inc.
Form: Tablet (Chewable)
Identifiers:
NADA: 141277 NADA: 141321 NDC Package: 58198-0042-1 NDC Package: 58198-0042-6 NDC Package: 58198-0043-1 NDC Package: 58198-0043-6 NDC Package: 58198-0044-1 NDC Package: 58198-0044-6 NDC Package: 58198-0045-1 NDC Package: 58198-0045-6 NDC Package: 58198-0046-1 NDC Package: 58198-0046-6 NDC Package: 58198-0071-1 NDC Package: 58198-0071-2 NDC Package: 58198-0072-1 NDC Package: 58198-0072-2 NDC Package: 58198-0073-1 NDC Package: 58198-0073-2 NDC Package: 58198-0074-1 NDC Package: 58198-0074-2
Source metadata:

Warnings / Contraindications

Federal law restricts this drug to use by or on the order of a licensed veterinarian. Federal (USA) law restricts this drug to use by or on the order of a licensed veterinarian. Treatment with fewer than 3 monthly doses after the last exposure to mosquitos may not provide complete heartworm prevention. Use with caution in breeding females. The safe use of TRIFEXIS in breeding males has not been evaluated. Use with caution in dogs with pre-existing epilepsy.

  • High: Federal law restricts this drug to use by or on the order of a licensed veterinarian. Federal (USA) law restricts this drug to use by or on the order of a licensed veterinarian. Treatment with fewer than 3 monthly doses after the last exposure to mosquitos may not provide complete heartworm prevention. Use with caution in breeding females. The safe use of TRIFEXIS in breeding males has not been evaluated. Use with caution in dogs with pre-existing epilepsy.
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
9
Matching reports
3
Active filters
1
Selected filters
Body system: Skin & allergy Clear
Reset
Showing up to 50 matching reports.

USA-USFDACVM-2025-US-070189

Received 2025-11-28 · MSK · MSK

Non-serious
Species
Dog
Breed
['Terrier (unspecified)', 'Spaniel (unspecified)']
Size / weight
10-24 lb (7.77 Kilogram)
Age
8+ years (17 Year)
Sex
Female Unknown
Region
USA
Reactions
ScratchingLack of efficacy (ectoparasite) - fleaItchingHair loss NOSAllergy NOS
Body systems
OtherEffectivenessSkin & allergy
Outcomes
Outcome Unknown

USA-USFDACVM-2025-US-067101

Received 2025-10-30 · MSK · MSK

Non-serious
Species
Dog
Breed
['Shepherd Dog - Australian', 'Dog (unknown)']
Size / weight
100+ lb (54.4 Kilogram)
Age
8+ years (8 Year)
Sex
Unknown Unknown
Region
USA
Reactions
Biting - pruritus (see also Behavioural disorders)Skin scabChewing - pruritus (see also Oral cavity disorders)Generalised itchingLack of efficacy (ectoparasite) - flea
Body systems
Skin & allergyOtherEffectiveness
Outcomes
Ongoing

USA-USFDACVM-2025-US-066601

Received 2025-10-30 · MSK · MSK

Serious
Species
Dog
Breed
['Pit Bull', 'Boxer (German Boxer)']
Size / weight
100+ lb (45.5 Kilogram)
Age
8+ years (9 Year)
Sex
Female Neutered
Region
USA
Reactions
Biting - pruritus (see also Behavioural disorders)Lack of efficacy (ectoparasite) - fleaGeneralised itchingSkin scabSeizure NOS
Body systems
Skin & allergyEffectivenessOtherNeurologic
Outcomes
Ongoing

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

Tracked signals
30
Reported cases
28
Serious reports
5
Species represented
2
Grouped by Body System
Digestive (1) · Vomiting Skin & allergy (5) · Itching, Hair loss NOS, Generalised itching Neurologic (2) · Tiredness (lethargy), Seizure NOS Behavior (1) · Behavioral disorder (unspecified) Effectiveness (2) · Lack of efficacy (endoparasite) - heartworm, Lack of efficacy (ectoparasite) - flea Other (19) · Weight loss, UNPALATABLE, Tongue protrusion
Most Reported Reactions
Reaction Body system Cases Species Serious cases
Other 1 Dog 1
Neurologic 1 Dog 1
Skin & allergy 1 Dog 1
Other 1 Dog 1
Skin & allergy 1 Dog 1
Other 1 Cat 0
Digestive 1 Dog 0
Other 1 Cat 0

Species coverage: Dog (21) Cat (9)

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

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

Owner handouts

0
No owner handouts linked yet.

Official label / PI

2

SPL

2

FOI

3

COMFORTIS N141277.pdf

Official label / PI · Labeling

TRIFEXIS N141321C0060.pdf

Official label / PI · Official label

Comfortis®

SPL · SPL

FDA Structured Product Label

Comfortis®

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

Sponsor
Elanco US Inc.
NADA
141-277
Status
RX
Form
Tablet (Chewable)
Route
Oral
Species
Dog • Cat
Composition / specifications
Each chewable tablet contains 140, 270, 560, 810, or 1620 milligrams (mg) spinosad.

Dogs

Indication

To kill fleas and for the prevention and treatment of flea infestations (Ctenocephalides felis) for 1 month on dogs and puppies 14 weeks of age and older and 5.0 pounds or body weight or greater.

Dosage
Administer tablets once a month at a recommended minimum dosage of 13.5 mg per pound (30 mg per kilogram) of body weight.
Limitations
Federal law restricts this drug to use by or on the order of a licensed veterinarian.

Cats

Indication

To kill fleas and for the prevention and treatment of flea infestations (Ctenocephalides felis) for 1 month on cats and kittens 14 weeks of age and older and 4.1 pounds of body weight or greater.

Dosage
Administer tablets once a month at the minimum dosage of 22.5 mg per pound (50 mg per kilogram) of body weight.
Limitations
Federal law restricts this drug to use by or on the order of a licensed veterinarian.

Comfortis SPL

SPL · Structured Product Label

FDA Structured Product Label XML for Comfortis. Use the source link for the full official labeling record.

UCM326907.pdf

FOI · FOI

ucm062334.pdf

FOI · FOI

UCM252248.pdf

FOI · FOI summary

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, 10:40 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.
  • Animal Drug Product Listing Directory (NDC): Source FDA | Refreshed Jun 22, 2026, 10:41 AM UTC
    Package/product NDCs from FDA’s electronic listing directory (XLS).
  • 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 • FDA branded products available
Official FDA brands: Comfortis
Manufacturer mapping: Elanco US Inc.
Case-reported brands (openFDA): MSK
Catalog species: Both FDA-labeled species: Cat, Dog
Rx/OTC: RX
Form/route: Tablet (Chewable) Oral
Applications: NADA 141-277
NDC: Packages 58198-0071-1 58198-0071-2 58198-0072-1 58198-0072-2 58198-0073-1 58198-0073-2 Products 58198
Documents: 3 (FOI: 2) • SPL: 1 Label highlights Official documents
Safety (openFDA)
Top reactions: Dog 10 Cat 5 View
Case summaries: 9 (showing 8) View
openFDA reports are unverified and do not prove causation.

Explore
Related conditions: Fleas (Flea Infestation)
Linked using: Fda_Label (0.95)

Diagnosis Codes
ICD10_CM: B74.8 ICD10_CM: B88.1
Other filariases

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
  • Federal law restricts this drug to use by or on the order of a licensed veterinarian. Federal (USA) law restricts this drug to use by or on the order of a licensed veterinarian. Treatment with fewer than 3 monthly doses after the last exposure to mosquitos may not provide complete heartworm prevention. Use with caution in breeding females. The safe use of TRIFEXIS in breeding males has not been evaluated. Use with caution in dogs with pre-existing epilepsy. (Contraindication, High)
Top reaction signals
Skin scab (1) Seizure NOS (1) Generalised itching (1) Death (1) Biting - pruritus (1) Weight loss (1) Vomiting (1) UNPALATABLE (1)

Identifiers & Packages

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

Identifiers
NADA: 141277 NADA: 141321 NDC Package: 58198-0042-1 NDC Package: 58198-0042-6 NDC Package: 58198-0043-1 NDC Package: 58198-0043-6 NDC Package: 58198-0044-1 NDC Package: 58198-0044-6 NDC Package: 58198-0045-1 NDC Package: 58198-0045-6 NDC Package: 58198-0046-1 NDC Package: 58198-0046-6 NDC Package: 58198-0071-1 NDC Package: 58198-0071-2 NDC Package: 58198-0072-1 NDC Package: 58198-0072-2 NDC Package: 58198-0073-1 NDC Package: 58198-0073-2 NDC Package: 58198-0074-1 NDC Package: 58198-0074-2 NDC Package: 58198-0075-1 NDC Package: 58198-0075-2 NDC Package: 73064-0305-1 NDC Product: 58198
Package NDC Product NDC Form / Route Status
58198-0042-1 58198 -
58198-0042-6 58198 -
58198-0043-1 58198 -
58198-0043-6 58198 -
58198-0044-1 58198 -
58198-0044-6 58198 -
58198-0045-1 58198 -
58198-0045-6 58198 -
58198-0046-1 58198 -
58198-0046-6 58198 -
58198-0071-1 58198 -
58198-0071-2 58198 -
58198-0072-1 58198 -
58198-0072-2 58198 -
58198-0073-1 58198 -
58198-0073-2 58198 -
58198-0074-1 58198 -
58198-0074-2 58198 -
58198-0075-1 58198 -
58198-0075-2 58198 -

Enriched Documents

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

  • Comfortis SPL • Structured Product Label • Official
    FDA Structured Product Label from the electronic animal drug product listing directory.
  • COMFORTIS N141277.pdf • Official label • Official • May 17, 2021
    FDA official labeling for application 141277
  • ucm062334.pdf • FOI summary • Official • May 17, 2021
    FDA FOI summary for application 141277
  • UCM326907.pdf • FOI summary • Official • May 17, 2021
    FDA FOI summary for application 141277
  • TRIFEXIS N141321C0060.pdf • Official label • Official • May 17, 2021
    FDA official labeling for application 141321
  • UCM252248.pdf • FOI summary • Official • May 17, 2021
    FDA FOI summary for application 141321

Data Sources & Change Log

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

Official 125 Clinical 1 Manufacturer 0 Marketing 0
Current Field Facts
  • side_effects: Top reported reactions (openFDA): Vomiting, Lethargy (see also Central nervous system depression in 'Neurological'), Lack of efficacy (endoparasite) - heartwor… (Clinical, 2026-04-11)
  • contraindications: Federal law restricts this drug to use by or on the order of a licensed veterinarian. Federal (USA) law restricts this drug to use by or on the order of a lice… (Official, 2026-04-12)
  • contraindications: Federal law restricts this drug to use by or on the order of a licensed veterinarian. Federal (USA) law restricts this drug to use by or on the order of a lice… (Official, 2026-04-11)
  • contraindications: Federal law restricts this drug to use by or on the order of a licensed veterinarian. Federal (USA) law restricts this drug to use by or on the order of a lice… (Official, 2026-02-12)
  • indications: Kill fleas and are indicated for the prevention and treatment of flea infestations ( Ctenocephalides felis) on dogs for one month. 1) To add an indication for … (Official, 2026-06-22)
  • indications: Kill fleas and are indicated for the prevention and treatment of flea infestations ( Ctenocephalides felis) on dogs for one month. 1) To add an indication for … (Official, 2026-06-22)
  • indications: Kill fleas and are indicated for the prevention and treatment of flea infestations ( Ctenocephalides felis) on dogs for one month. 1) To add an indication for … (Official, 2026-06-21)
  • indications: Kill fleas and are indicated for the prevention and treatment of flea infestations ( Ctenocephalides felis) on dogs for one month. 1) To add an indication for … (Official, 2026-06-20)
  • indications: Kill fleas and are indicated for the prevention and treatment of flea infestations ( Ctenocephalides felis) on dogs for one month. 1) To add an indication for … (Official, 2026-06-13)
  • indications: Kill fleas and are indicated for the prevention and treatment of flea infestations ( Ctenocephalides felis) on dogs for one month. 1) To add an indication for … (Official, 2026-06-12)
  • indications: Kill fleas and are indicated for the prevention and treatment of flea infestations ( Ctenocephalides felis) on dogs for one month. 1) To add an indication for … (Official, 2026-06-12)
  • indications: Kill fleas and are indicated for the prevention and treatment of flea infestations ( Ctenocephalides felis) on dogs for one month. 1) To add an indication for … (Official, 2026-06-11)
  • indications: Kill fleas and are indicated for the prevention and treatment of flea infestations ( Ctenocephalides felis) on dogs for one month. 1) To add an indication for … (Official, 2026-06-11)
  • indications: Kill fleas and are indicated for the prevention and treatment of flea infestations ( Ctenocephalides felis) on dogs for one month. 1) To add an indication for … (Official, 2026-06-10)
  • indications: Kill fleas and are indicated for the prevention and treatment of flea infestations ( Ctenocephalides felis) on dogs for one month. 1) To add an indication for … (Official, 2026-06-09)
  • indications: Kill fleas and are indicated for the prevention and treatment of flea infestations ( Ctenocephalides felis) on dogs for one month. 1) To add an indication for … (Official, 2026-06-08)
  • indications: Kill fleas and are indicated for the prevention and treatment of flea infestations ( Ctenocephalides felis) on dogs for one month. 1) To add an indication for … (Official, 2026-06-07)
  • indications: Kill fleas and are indicated for the prevention and treatment of flea infestations ( Ctenocephalides felis) on dogs for one month. 1) To add an indication for … (Official, 2026-06-06)
  • indications: Kill fleas and are indicated for the prevention and treatment of flea infestations ( Ctenocephalides felis) on dogs for one month. 1) To add an indication for … (Official, 2026-06-05)
  • indications: Kill fleas and are indicated for the prevention and treatment of flea infestations ( Ctenocephalides felis) on dogs for one month. 1) To add an indication for … (Official, 2026-06-04)
Recent Revisions
  • side_effects updated 2026-04-12 10:05 by etl_backfill • Backfilled from existing medication fields
  • contraindications updated 2026-04-12 10:05 by etl_backfill • Backfilled from existing medication fields
  • usage updated 2026-04-12 10:05 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
  • usage 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
Comfortis®
RX
Spinosad
Tablet (Chewable) Oral
Elanco US Inc. NADA 141-277 Approved May 17, 2021

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 • Cat
Composition / specifications
Each chewable tablet contains 140, 270, 560, 810, or 1620 milligrams (mg) spinosad.
Dogs
Indication

To kill fleas and for the prevention and treatment of flea infestations (Ctenocephalides felis) for 1 month on dogs and puppies 14 weeks of age and older and 5.0 pounds or body weight or greater.

Dosage
Administer tablets once a month at a recommended minimum dosage of 13.5 mg per pound (30 mg per kilogram) of body weight.
Limitations
Federal law restricts this drug to use by or on the order of a licensed veterinarian.
Cats
Indication

To kill fleas and for the prevention and treatment of flea infestations (Ctenocephalides felis) for 1 month on cats and kittens 14 weeks of age and older and 4.1 pounds of body weight or greater.

Dosage
Administer tablets once a month at the minimum dosage of 22.5 mg per pound (50 mg per kilogram) of body weight.
Limitations
Federal law restricts this drug to use by or on the order of a licensed veterinarian.

FDA page: Open in Animal Drugs @ FDA

Usage

To kill fleas and for the prevention and treatment of flea infestations ( Ctenocephalides felis ) for 1 month on dogs and puppies 14 weeks of age and older and 5.0 pounds or body weight or greater. To kill fleas and for the prevention and treatment of flea infestations ( Ctenocephalides felis ) for 1 month on cats and kittens 14 weeks of age and older and 4.1 pounds of body weight or greater. Trifexis™ Chewable Tablets kill fleas and are indicated for the prevention and treatment of flea infestations ( Ctenocephalides felis ), and the treatment and control of adult hookworm ( Ancylostoma caninum ), adult roundworm ( Toxocara canis and Toxascaris leonina ) and adult whipworm ( Trichuris vulpis ) infections in dogs and puppies 8 weeks of age or older and 5 pounds of body weight or greater.

Source: FDA Animal Drugs @ FDA • Reference

Contraindications

Federal law restricts this drug to use by or on the order of a licensed veterinarian. Federal (USA) law restricts this drug to use by or on the order of a licensed veterinarian. Treatment with fewer than 3 monthly doses after the last exposure to mosquitos may not provide complete heartworm prevention. Use with caution in breeding females. The safe use of TRIFEXIS in breeding males has not been evaluated. Use with caution in dogs with pre-existing epilepsy.

Top Reported Reactions (openFDA)

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

Digestive
Vomiting (1) • Dog

Showing top 5 for Digestive.

Skin & allergy
Itching (1) • Cat Hair loss NOS (1) • Dog Generalised itching (1) • Dog Chewing - pruritus (1) • Dog Biting - pruritus (1) • Dog

Showing top 5 for Skin & allergy.

Neurologic
Tiredness (1) • Dog Seizure NOS (1) • Dog

Showing top 5 for Neurologic.

Behavior
Behavioral disorder (1) • Dog

Showing top 5 for Behavior.

Effectiveness
Lack of efficacy (endoparasite) - heartworm (1) • Dog Lack of efficacy (ectoparasite) - flea (1) • Cat

Showing top 5 for Effectiveness.

Other
Weight loss (1) • Cat UNPALATABLE (1) • Cat Tongue protrusion (1) • Cat Skin scab (1) • Dog Shaking (1) • Dog
Show more (14)
Scratching (1) • Dog Panting (1) • Cat Overdose (1) • Dog Malaise (1) • Dog Licking (1) • Cat Incorrect dose administered NOS (1) • Cat Hyperactivity (1) • Cat Falling (1) • Dog Difficulty standing (1) • Dog Death (1) • Dog Allergy NOS (1) • Dog Accidental exposure (1) • Dog Arthritis • Dog Administration error NOS • Dog

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, Poodle - Miniature, Male, 17 year, 8.618 kilogram • Drug: MSK, Tablet, Oral, Dose: 1 tablet per animal • Reactions: Lack of efficacy (ectoparasite) - flea • Outcome: Ongoing

  • Report ID: USA-USFDACVM-2025-US-074769
  • Serious AE: No
  • Treated For AE: Yes
  • Sex: Male
  • Age: 17.00 Year
  • Weight: 8.618 Kilogram
  • Case-reported brand: MSK
  • Case-reported manufacturer: MSK
  • Route: Oral
  • Form: Tablet
  • Dose: 1 tablet per animal
Reactions Reported:
Lack of efficacy (ectoparasite) - flea
Outcomes: Ongoing

Dog, ['Poodle - Miniature', 'Dog (unknown)'], Male, 17 year, 8.618 kilogram • Drug: MSK, Tablet, chewable, Oral, Dose: 1 tablet per animal • Reactions: Scratching, Lack of efficacy (ectoparasite) - flea • Outcome: Ongoing

  • Report ID: USA-USFDACVM-2025-US-071144
  • Serious AE: No
  • Treated For AE: Yes
  • Sex: Male
  • Age: 17.00 Year
  • Weight: 8.618 Kilogram
  • Case-reported brand: MSK
  • Case-reported manufacturer: MSK
  • Route: Oral
  • Form: Tablet, chewable
  • Dose: 1 tablet per animal
Reactions Reported:
Scratching Lack of efficacy (ectoparasite) - flea
Outcomes: Ongoing

Dog, ['Terrier (unspecified)', 'Spaniel (unspecified)'], Female, 17 year, 7.77 kilogram • Drug: MSK, Tablet, chewable, Oral, Dose: 1 tablet per animal • Reactions: Scratching, Lack of efficacy (ectoparasite) - flea, Itching, Hair loss NOS, Allergy NOS • Outcome: Outcome Unknown

  • Report ID: USA-USFDACVM-2025-US-070189
  • Serious AE: No
  • Treated For AE: Yes
  • Sex: Female
  • Age: 17.00 Year
  • Weight: 7.770 Kilogram
  • Case-reported brand: MSK
  • Case-reported manufacturer: MSK
  • Route: Oral
  • Form: Tablet, chewable
  • Dose: 1 tablet per animal
Reactions Reported:
Scratching Lack of efficacy (ectoparasite) - flea Itching Hair loss NOS Allergy NOS
Outcomes: Outcome Unknown

Cat, Domestic Shorthair, Female, 1.49 year, 3.62 kilogram • Drug: MSK, Tablet, chewable, Oral, Dose: 1 tablet per animal • Reactions: Vomiting, Incorrect dose administered NOS • Outcome: Recovered/Normal

  • Report ID: USA-USFDACVM-2025-US-066982
  • Serious AE: No
  • Treated For AE: Yes
  • Sex: Female
  • Age: 1.49 Year
  • Weight: 3.620 Kilogram
  • Case-reported brand: MSK
  • Case-reported manufacturer: MSK
  • Route: Oral
  • Form: Tablet, chewable
  • Dose: 1 tablet per animal
Reactions Reported:
Vomiting Incorrect dose administered NOS
Outcomes: Recovered/Normal

Dog, ['Shepherd Dog - Australian', 'Dog (unknown)'], Unknown, 8 year, 54.4 kilogram • Drug: MSK, Tablet, chewable, Oral, Dose: 1 tablet per animal • Reactions: Biting - pruritus, Skin scab, Chewing - pruritus, Generalised itching, Lack of efficacy (ectoparasite) - flea • Outcome: Ongoing

  • Report ID: USA-USFDACVM-2025-US-067101
  • Serious AE: No
  • Treated For AE: Yes
  • Sex: Unknown
  • Age: 8.00 Year
  • Weight: 54.400 Kilogram
  • Case-reported brand: MSK
  • Case-reported manufacturer: MSK
  • Route: Oral
  • Form: Tablet, chewable
  • Dose: 1 tablet per animal
Reactions Reported:
Biting - pruritus Skin scab Chewing - pruritus Generalised itching Lack of efficacy (ectoparasite) - flea
Outcomes: Ongoing

Dog, ['Pit Bull', 'Boxer (German Boxer)'], Female, 9 year, 45.5 kilogram • Drug: MSK, Tablet, chewable, Oral, Dose: 1 tablet per animal • Reactions: Biting - pruritus, Lack of efficacy (ectoparasite) - flea, Generalised itching, Skin scab, Seizure NOS • Outcome: Ongoing

  • Report ID: USA-USFDACVM-2025-US-066601
  • Serious AE: Yes
  • Treated For AE: Yes
  • Sex: Female
  • Age: 9.00 Year
  • Weight: 45.500 Kilogram
  • Case-reported brand: MSK
  • Case-reported manufacturer: MSK
  • Route: Oral
  • Form: Tablet, chewable
  • Dose: 1 tablet per animal
Reactions Reported:
Biting - pruritus Lack of efficacy (ectoparasite) - flea Generalised itching Skin scab Seizure NOS
Outcomes: Ongoing

Cat, Domestic Shorthair, Male, 5 year, 6.08 kilogram • Drug: MSK, Tablet, chewable, Oral, Dose: 1 tablet per animal • Reactions: Lack of efficacy (ectoparasite) - flea • Outcome: Outcome Unknown

  • Report ID: USA-USFDACVM-2025-US-065550
  • Serious AE: No
  • Treated For AE: No
  • Sex: Male
  • Age: 5.00 Year
  • Weight: 6.080 Kilogram
  • Case-reported brand: MSK
  • Case-reported manufacturer: MSK
  • Route: Oral
  • Form: Tablet, chewable
  • Dose: 1 tablet per animal
Reactions Reported:
Lack of efficacy (ectoparasite) - flea
Outcomes: Outcome Unknown

Cat, Domestic Mediumhair, Female, 6 year, 4.082 kilogram • Drug: MSK, Tablet, chewable, Oral, Dose: 1 tablet per animal • Reactions: Vomiting • Outcome: Recovered/Normal

  • Report ID: USA-USFDACVM-2025-US-061961
  • Serious AE: No
  • Treated For AE: No
  • Sex: Female
  • Age: 6.00 Year
  • Weight: 4.082 Kilogram
  • Case-reported brand: MSK
  • Case-reported manufacturer: MSK
  • Route: Oral
  • Form: Tablet, chewable
  • Dose: 1 tablet per animal
Reactions Reported:
Vomiting
Outcomes: Recovered/Normal

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

No approved storage guidance is linked yet for this ingredient. Use manufacturer packaging and veterinary guidance for handling/storage.

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