A Guide to Fentanyl for Dogs and Cats - The High Strength Opiate

How This Super Powered Pain Reliever Can Help Your Pet

By Sam Bourne.

indications for Fentanyl

Fentanyl is a highly concentrated and extremely potent mu and kappa opiate agonist, with an strength estimated to be 50-100 times stronger than morphine. Traditionally used in chronic cases, the fentanyl patch is an easy and effective way to manage your pets moderate to severe pain. Sometimes used to sedate or tranquilize, this drug needs to be used with great caution, since it is so powerful.


Since fentanyl is so powerful and addictive, dosages should be carefully monitored. Caution should be taken when giving fentanyl to elderly or severely debilitated pets, or those with pre existing respiratory problems. Fentanyl should only be used in pregnant pets when the benefits outweigh the risks.

Fentanyl can cause elevated amylase and lipase. Use with CNS depressants can cause additive sedation and respiratory depression. Use with MAOIs is contraindicated and should never be given. Use with opiate antagonists and partial opiate antagonists are going to diminish the analgesic effects.

Naloxone can be used to treat respiratory depression effects after a fentanyl overdose.


For the patch - never cut in half. If prescribed with a half patch dosage, cover half with a gel tape.

Since this drug is so strong, and the correct dosage varies depending on the size of your pet, you should only ever administer the dosage specifically prescribed by your veterinarian.

Brand/Generic equivalents

Duragesic, Sublimase, Carpujects, FentaNYL, Oralet, Actiq

Side Effects

The most common side effects of fentanyl can be respiratory depression and bradycardia, but other side effects, such as rashes at applications site, urine retention, constipation, confusion, sedation, or dysphoria, may occur.

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Fentanyl at a glance

  • 1For dogs and cats
  • 2Opiate medication
  • 3Taken as a patch, lozenge, pill, dissolvable film, shot, or IV
  • 4Blocks pain receptors in the brain and spinal cord

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