VETINUITY
Why do Labradors come up in carprofen liver warnings?
In the first case series of carprofen-associated hepatocellular toxicosis, Labrador retrievers were overrepresented. The reaction is idiosyncratic and can occur in any breed.
● ANSWER
Sourced & dated
What is the carprofen dose for dogs and cats?
Carprofen is dosed at 4.4 mg/kg once daily or 2.2 mg/kg twice daily, PO or SC, in dogs; it is not labeled for cats in the US, and some other countries label only a single 4 mg/kg perioperative injection in cats.
● VETINUITY CARPROFEN DOSE CALCULATOR
Vetinuity carprofen dose calculator
Injection 50 mg/mL. Tablets 25, 75 and 100 mg; round to the nearest half tablet below the calculated dose.
● WHAT'S DOCUMENTED
Vetinuity’s carprofen dose table gives dogs 4.4 mg/kg once a day or 2.2 mg/kg twice a day, by mouth or SC, for osteoarthritis and postoperative pain, starting about 2 hours before surgery when used perioperatively. Cats are not on the US label; a few other countries label one 4 mg/kg SC injection at surgery and nothing after. The Vetinuity carprofen dose calculator above gives the dog dose in milligrams and in millilitres of the 50 mg/mL injection.
Dose table
| Indication | Dog | Cat | Route and frequency |
|---|---|---|---|
| Osteoarthritis | 4.4 mg/kg, or 2.2 mg/kg | Not labeled in the US | PO q24h, or PO q12h |
| Postoperative pain | 4.4 mg/kg about 2 h before surgery | Single 4 mg/kg SC where labeled | SC or PO, then q24h in dogs |
Liver reactions
MacPhail and colleagues described hepatocellular toxicosis in 21 dogs, most within the first few weeks of treatment, with Labrador retrievers overrepresented. Clinical signs were anorexia, vomiting and icterus, with marked rises in ALT and bilirubin; most dogs recovered after the drug was stopped and supportive care given. Check a chemistry panel before starting and a few weeks in, and teach owners to stop the drug and call if the dog stops eating.
Kidneys and gut
Like every NSAID, carprofen reduces renal prostaglandins, so it is withheld in dehydrated, hypotensive or azotemic dogs and is not combined with corticosteroids or another NSAID. GI ulceration presents as vomiting, melena or a falling PCV; stop the drug and start gastroprotection such as pantoprazole. Chewable tablets are palatable, which is how many dogs end up eating a whole bottle; that scenario is covered on the NSAID overdose page.
Comparing NSAIDs
Pollmeier and colleagues compared firocoxib with carprofen in dogs with osteoarthritis. In practice the choice among NSAIDs comes down to dosing interval, formulation and the individual dog’s response; never switch between them without a washout.
Vetinuity is the clinical assistant from Brian Toncray, DVM, an emergency vet, and it groups carprofen with meloxicam, robenacoxib and the adjunct gabapentin.
● SOURCES
- 1. DailyMed: Rimadyl (carprofen) label search. Dosage and Administration; Warnings. Checked 2026-10-26.
- 2. MacPhail CM, Lappin MR, Meyer DJ, et al. Hepatocellular toxicosis associated with administration of carprofen in 21 dogs. J Am Vet Med Assoc. 1998;212(12):1895-1901. PMID 9638189. Abstract. Checked 2026-10-26.
- 3. Pollmeier M, Toulemonde C, Fleishman C, et al. Clinical evaluation of firocoxib and carprofen for the treatment of dogs with osteoarthritis. Vet Rec. 2006;159(17):547-551. PMID 17056650. Abstract. Checked 2026-10-26.
● RELATED ANSWERS
- Ibuprofen and NSAID Overdose in Dogs: Toxic Doses
Ibuprofen causes GI signs in dogs from 100-125 mg/kg, renal failure from 175-300 mg/kg, CNS signs above 400 mg/kg and can be lethal above 600 mg/kg; naproxen is toxic at far lower doses.
- Meloxicam Dose for Dogs and Cats (Metacam)
Meloxicam is dosed at 0.2 mg/kg once, then 0.1 mg/kg once daily in dogs; in US cats the label allows a single 0.3 mg/kg SC injection only, while some other countries label 0.05 mg/kg PO daily long term.
- Robenacoxib (Onsior) Dose for Dogs and Cats
Robenacoxib is 2 mg/kg SC once daily in dogs and cats, or tablets once daily (2 mg/kg in dogs, 1 mg/kg in cats), for a short label course starting before surgery.
- Gabapentin Dose for Dogs and Cats
Gabapentin is dosed at 5-10 mg/kg PO every 8-12 hours in dogs and cats for chronic or neuropathic pain, and at 100 mg per cat PO about 90 minutes before a veterinary visit.
- Pantoprazole (Protonix) IV Dose for Dogs and Cats
Pantoprazole is given at 1 mg/kg IV over 15 minutes every 12 hours in dogs and 1 mg/kg IV every 12-24 hours in cats, switching to an oral PPI once the patient eats.
● FAQ
When should liver values be checked on long-term carprofen?
Before starting, again within the first few weeks, and periodically after that, with a recheck any time the dog stops eating, vomits or turns icteric.
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