Pet Safety / Compounds / Hydrocodone

Is Hydrocodone safe for dogs and cats?

High risk for pets

(Dogs-specific data is limited; this page draws from cat context.) Cats are markedly more sensitive to hydrocodone and all opioids than dogs due to differences in hepatic glucuronidation capacity and slower metabolism. A small amount of hydrocodone can produce prolonged and severe CNS and respiratory depression in cats. The acetaminophen component in combination hydrocodone/APAP products (Vicodin, Norco) presents an independent extreme hazard: even a 1/4 tablet of standard combination Vicodin delivers an acetaminophen dose sufficient to cause methemoglobinemia and hepatic necrosis in a cat. Combined opioid and acetaminophen toxicosis in cats represents a veterinary emergency with multiple simultaneous life threats. N-acetylcysteine (NAC) is indicated for acetaminophen toxicity; naloxone reverses opioid component; methylene blue or SAMe for methemoglobin.

What is hydrocodone?

The IUPAC name is (4R,4aR,7aR,12bS)-9-methoxy-3-methyl-1,2,4,4a,5,6,7a,13-octahydro-4,12-methanobenzofuro[3,2-e]isoquinolin-7-one.

Also known as: (4R,4aR,7aR,12bS)-9-methoxy-3-methyl-1,2,4,4a,5,6,7a,13-octahydro-4,12-methanobenzofuro[3,2-e]isoquinolin-7-one, Dihydrocodeinone, Hydrocodon, Hydrocone.

IUPAC name
(4R,4aR,7aR,12bS)-9-methoxy-3-methyl-1,2,4,4a,5,6,7a,13-octahydro-4,12-methanobenzofuro[3,2-e]isoquinolin-7-one
CAS number
125-29-1
Molecular formula
C18H21NO3
Molecular weight
299.4 g/mol
SMILES
CN1CCC23C4C1CC5=C2C(=C(C=C5)OC)OC3C(=O)CC4
PubChem CID
5284569

Risk for dogs

High risk

Cats are markedly more sensitive to hydrocodone and all opioids than dogs due to differences in hepatic glucuronidation capacity and slower metabolism. A small amount of hydrocodone can produce prolonged and severe CNS and respiratory depression in cats. The acetaminophen component in combination hydrocodone/APAP products (Vicodin, Norco) presents an independent extreme hazard: even a 1/4 tablet of standard combination Vicodin delivers an acetaminophen dose sufficient to cause methemoglobinemia and hepatic necrosis in a cat. Combined opioid and acetaminophen toxicosis in cats represents a veterinary emergency with multiple simultaneous life threats. N-acetylcysteine (NAC) is indicated for acetaminophen toxicity; naloxone reverses opioid component; methylene blue or SAMe for methemoglobin.

Risk for cats

High risk

Cats are markedly more sensitive to hydrocodone and all opioids than dogs due to differences in hepatic glucuronidation capacity and slower metabolism. A small amount of hydrocodone can produce prolonged and severe CNS and respiratory depression in cats. The acetaminophen component in combination hydrocodone/APAP products (Vicodin, Norco) presents an independent extreme hazard: even a 1/4 tablet of standard combination Vicodin delivers an acetaminophen dose sufficient to cause methemoglobinemia and hepatic necrosis in a cat. Combined opioid and acetaminophen toxicosis in cats represents a veterinary emergency with multiple simultaneous life threats. N-acetylcysteine (NAC) is indicated for acetaminophen toxicity; naloxone reverses opioid component; methylene blue or SAMe for methemoglobin.

Regulatory consensus

1 regulatory bodyhas classified Hydrocodone.

AgencyYearClassificationNotes
DEA2014Schedule IIRescheduled from Schedule III in 2014

Regulators apply different standards of evidence — animal-data weighting, exposure-pattern assumptions, epidemiological power thresholds — which is why two scientific bodies can review the same data and reach different conclusions. The disagreement is the data.

Where pets encounter hydrocodone

  • Industrial Facilities — Manufacturing plants, Chemical storage areas, Waste treatment sites
  • Occupational Environments — Factories, Warehouses, Transportation vehicles

Safer alternatives

Lower-risk approaches that achieve a similar outcome to Hydrocodone:

  • Therapeutic alternatives (consult prescriber)
    Trade-offs: Drug-specific. Cannot substitute without medical guidance.
    Relative cost: 1.2-2×

Frequently asked questions

What products contain hydrocodone?

Hydrocodone appears in: Manufacturing plants (Industrial facilities); Chemical storage areas (Industrial facilities); Factories (Occupational environments); Warehouses (Occupational environments).

See Hydrocodone in the pets app

Look up products containing hydrocodone, compare to alternatives, and explore the full data record.

Open in pets View raw API data

Sources (3)
  1. US DEA: Hydrocodone Combination Products — Rescheduling from Schedule III to Schedule II (2014), Prescribing Volume Reduction Post-Rescheduling, CYP2D6 Ultra-Rapid Metabolizer Risk, and Extended-Release Formulation Hazard (2022) (2022) — regulatory
  2. US FDA: Hydrocodone/Acetaminophen Combination Products — ≤325 mg APAP/Tablet Mandate, Extended-Release Hydrocodone (Zohydro ER) Risk Evaluation, Pediatric Accidental Ingestion Data, and Abuse-Deterrent Formulation Requirements (2022) (2022) — regulatory
  3. ASPCA Animal Poison Control Center: Opioid Analgesics in Dogs and Cats — Oxycodone, Hydrocodone, Tramadol; Respiratory Depression Severity; Naloxone Veterinary Dosing; and APCC Case Data (2022) (2022) — regulatory

Reference data, not professional advice. Aggregates publicly available regulatory and scientific data; not a substitute for veterinary, medical, legal, or regulatory advice. Why we built ALETHEIA →