What Is Carprofen and What Does It Treat?
Carprofen is a non-steroidal anti-inflammatory drug (NSAID) and one of the most widely prescribed pain medications for dogs. It is best known by the brand name Rimadyl, and is also sold as Novox, Rovera, Vetprofen, Carprieve and other generics. Carprofen is FDA-approved for dogs.
Carprofen works by blocking cyclooxygenase (COX) enzymes, which the body uses to make prostaglandins — the chemical messengers that drive pain, inflammation, swelling and fever. By reducing prostaglandin production at sites of injury or disease, carprofen relieves pain and inflammation.
Veterinarians most commonly prescribe carprofen for:
- Osteoarthritis and chronic joint pain — it is a mainstay of long-term arthritis management.
- Post-operative pain — for example after spays, neuters and orthopaedic surgery.
- Acute pain and inflammation — from soft-tissue injuries, sprains and strains.
Carprofen is genuinely effective and, when used correctly, has a good safety record — but it is still an NSAID, and NSAIDs require respect. Correct dosing and an awareness of the warning signs are essential. Use the calculator above to understand the standard dose, but a veterinarian must confirm carprofen is appropriate for your individual dog. For more, see PuppaDogs’ guide to carprofen for dogs.
How the Carprofen Dosage Calculator Works
The calculator converts your dog’s weight into the standard carprofen dose and then:
- Shows the total daily dose and the per-dose amount for once- or twice-daily dosing.
- Converts it into a number of 25 mg, 75 mg or 100 mg tablets or chews.
- Applies firm contraindication flags — combining NSAIDs with steroids, GI ulcers, kidney or liver disease and pregnancy all trigger clear warnings.
Enter your dog’s weight, choose the dosing plan, the reason for use and the tablet strength, tick any health considerations, then press Calculate Dose.
How Carprofen Doses Are Calculated for Dogs
The Standard Dose
The established label dose of carprofen for dogs is:
4.4 mg/kg of body weight per day (about 2 mg/lb).
This total can be given in either of two ways, which are equivalent:
- 4.4 mg/kg once daily, or
- 2.2 mg/kg every 12 hours (twice daily)
Many veterinarians favour splitting the dose into twice-daily administration, as it can keep pain control steadier through the day. Both plans deliver the same total daily amount.
Rounding to a Practical Tablet
Carprofen comes as tablets and flavoured chews in 25 mg, 75 mg and 100 mg strengths, which are scored for splitting. The calculator rounds the calculated dose to a practical fraction of the strength you select. Your veterinarian will pick the combination of strengths that gets closest to the ideal dose.
Carprofen Dosage Chart for Dogs
This chart shows the total daily dose (4.4 mg/kg) and how it splits. It is a reference only — your veterinarian’s prescription takes priority.
| Dog weight | Total daily (4.4 mg/kg) | Once daily | Twice daily (each dose) |
|---|---|---|---|
| 10 lb (4.5 kg) | ~20 mg | ~20 mg | ~10 mg |
| 20 lb (9 kg) | ~40 mg | ~40 mg | ~20 mg |
| 40 lb (18 kg) | ~80 mg | ~80 mg | ~40 mg |
| 60 lb (27 kg) | ~120 mg | ~120 mg | ~60 mg |
| 80 lb (36 kg) | ~160 mg | ~160 mg | ~80 mg |
| 100 lb (45 kg) | ~200 mg | ~200 mg | ~100 mg |
How to Give Carprofen to Your Dog
- Always give with food. This is the single most important habit for reducing the risk of stomach irritation.
- Be consistent with timing — once daily, or every 12 hours, at regular times.
- Use the flavoured chews if your dog accepts them; otherwise hide a tablet in food.
- Never combine carprofen with another NSAID (including aspirin) or with a steroid such as prednisone.
- Missed dose: give it when you remember unless the next dose is near, then skip it — never double up.
- Keep it secured. Carprofen chews are palatable, and dogs have been seriously harmed by eating a whole bottle.
Side Effects and Safety Warnings
Most dogs tolerate carprofen well, but because it is an NSAID, every owner should know the warning signs. The most common and important side effects involve the digestive system, kidneys and liver.
Stop the medication and contact your veterinarian right away if you notice any of these:
- Vomiting or diarrhoea
- Black, tarry or bloody stool
- Loss of appetite
- Unusual tiredness or lethargy
- Yellowing of the gums, skin or eyes (jaundice)
- Increased thirst or urination
- Changes in behaviour
These can be early signs of gastrointestinal ulceration, kidney injury or liver problems — the serious risks associated with NSAIDs. A well-known memory aid for NSAID warning signs is “BEST”: Behaviour change, Eating less, Skin redness or scabs, Tarry stool.
When Carprofen Should Be Avoided
Carprofen should not be used, or used only with great caution under veterinary direction, in dogs that:
- Are taking another NSAID or a corticosteroid — this combination is dangerous and a washout period is required when switching
- Have a history of stomach ulcers or GI bleeding
- Have kidney or liver disease
- Are dehydrated, in shock or seriously unwell
- Are pregnant or nursing
- Have a known sensitivity to carprofen
Monitoring Bloodwork
Because carprofen affects the liver and kidneys, your veterinarian will usually recommend blood tests before starting long-term treatment and periodically during it. This is a routine, sensible precaution — not a sign that something is wrong — and it allows any early changes to be caught promptly.
Overdose — Signs and What to Do
Carprofen overdose is a genuine emergency. Eating too much — often from a chewed-open bottle of palatable chews — can cause severe stomach ulceration, kidney failure and, at very high doses, neurological signs. If your dog eats more carprofen than prescribed, contact your veterinarian or an animal poison control service immediately, and bring the packaging so the amount can be assessed.
Treatment Duration and Monitoring
For acute pain, carprofen may be needed for only a few days to a couple of weeks. For osteoarthritis, it is often used long-term — which is appropriate under veterinary supervision, with periodic rechecks and bloodwork. Carprofen also works best as part of a multimodal arthritis plan alongside weight control, suitable exercise and other supportive measures; see PuppaDogs’ guide to anti-inflammatory supplements for dogs. If you ever need to switch your dog from carprofen to a different NSAID such as meloxicam, your vet will build in a washout period.
Conclusion
Carprofen (Rimadyl) is a highly effective, FDA-approved NSAID for canine pain and arthritis, dosed simply at 4.4 mg/kg per day — once daily or split twice daily. The calculator above gives you that dose and converts it into tablets. But carprofen is a medicine that demands respect: it must never be combined with other NSAIDs or steroids, it needs caution in dogs with kidney, liver or GI disease, and every owner should know the warning signs that mean “stop and call the vet.” Used correctly, under veterinary guidance and with the recommended monitoring, carprofen can dramatically improve the comfort and quality of life of a dog in pain.
Frequently Asked Questions
How much carprofen can I give my dog?
The standard dose of carprofen (Rimadyl) for dogs is 4.4 mg/kg of body weight per day. This can be given as 4.4 mg/kg once daily or split as 2.2 mg/kg every 12 hours – both deliver the same total. As a guide that is roughly 40 mg/day for a 20 lb dog and 80 mg/day for a 40 lb dog. Always have a veterinarian confirm the dose.
Can I give my dog carprofen and another pain medication together?
Carprofen must never be combined with another NSAID (including aspirin) or with a corticosteroid such as prednisone – the combination greatly increases the risk of severe stomach ulcers, GI bleeding and kidney damage. When switching between these drugs a washout period is essential, and only your veterinarian should manage it.
What are the side effects of carprofen in dogs?
Most dogs tolerate carprofen well, but as an NSAID it can affect the stomach, kidneys and liver. Stop the medication and contact your vet if you see vomiting, diarrhoea, black or tarry stool, loss of appetite, lethargy, yellow gums or increased thirst – these can be early signs of a serious reaction. Giving carprofen with food reduces the risk of stomach upset.
How long does carprofen take to work in dogs?
Carprofen usually begins easing pain and inflammation within 1-2 hours of a dose, with the fuller effect over the first day or two. For osteoarthritis, give it a consistent week or two before judging the overall benefit, as steady control builds with regular dosing.
Does my dog need blood tests while taking carprofen?
Yes, this is recommended. Because carprofen can affect the liver and kidneys, veterinarians usually run blood tests before starting long-term treatment and periodically during it. This routine monitoring is a sensible precaution that allows any early changes to be detected and addressed quickly.
Can carprofen be given to puppies or pregnant dogs?
Carprofen is generally used in adult dogs and is not recommended for pregnant or nursing dogs because its safety in pregnancy has not been established. Use in very young puppies is limited and should only ever be on the specific direction of a veterinarian, who will weigh the risks for that individual.
References & Further Reading
The dosing ranges and safety information on this page are drawn from the following veterinary references. Always defer to your own veterinarian and the manufacturer’s label for your specific product.
- Rimadyl (carprofen) – FDA-approved veterinary label and prescribing information. fda.gov.
- Plumb DC. Plumb’s Veterinary Drug Handbook. 10th ed. Hoboken, NJ: Wiley-Blackwell, 2023 – carprofen monograph.
- Merck Veterinary Manual. Nonsteroidal anti-inflammatory drugs (NSAIDs) in animals. merckvetmanual.com.
- U.S. FDA Center for Veterinary Medicine. Get the Facts about Pain Relievers for Pets – NSAIDs for dogs. fda.gov.
- PuppaDogs. Carprofen for Dogs: Benefits, Dosage, Side Effects, and More. puppadogs.com.
