Rimadyl (Carprofen) Dosage for Dogs by Weight

What the carprofen label says for dogs

Carprofen, sold as Rimadyl, Novox and generic caplets, is an NSAID that vets use for pain and inflammation in dogs, most often from arthritis and after surgery. The FDA-approved label for dogs sets the dose at 2 mg per pound of body weight per day, which is 4.4 mg per kg. That total can be given once daily, or split into two doses of 1 mg per pound each, twice daily. The calculator above does that arithmetic for your dog's weight and lets you choose the regimen the label describes.

Treat the result as a label check, not a prescription. Your vet chooses the regimen based on the condition, the dog's age, its kidney and liver health, and any other medications. If the directions on your bottle differ from the label arithmetic, follow the bottle and ask your vet or pharmacist to explain the difference.

Worked example: a 50 lb dog

A 50 lb dog on the once-daily regimen gets 2 × 50 = 100 mg per day in total. On the twice-daily regimen, that is 1 × 50 = 50 mg per dose, twice a day, which is still 100 mg per day. The total is the same; only the timing changes.

The question that follows is how to make that total with the caplet strength on your bottle. The calculator shows whole and half caplets for your chosen strength. Half-caplet rounding is only appropriate if the caplet is scored and the vet or label allows splitting. Do not split an unscored caplet, because the dose will be uneven.

A 20 lb dog on the same regimen gets 40 mg per day in total. The same arithmetic applies at every weight, which is why the calculator is useful for checking a prescription at a glance.

Reading the calculator result

1. Enter your dog's weight in pounds. If you only have kilograms, convert first: 1 kg is about 2.2 lb.
2. Choose once daily or twice daily to match your prescription.
3. Select the caplet strength on your bottle. The tool shows how many whole or half caplets make up the dose.
4. Compare the number with the directions your vet wrote. If they match, you are reading the label correctly. If they do not, call your vet before giving the next dose.

Who should not use carprofen without a vet check

Carprofen should not be combined with other NSAIDs, such as meloxicam, aspirin or human ibuprofen. The label also warns against using it with corticosteroids such as prednisone unless your vet has specifically decided on the combination. Dogs with liver disease, kidney disease, bleeding disorders or stomach ulcers need careful assessment before starting. Puppies and dogs with certain heart or blood conditions also need a vet decision.

Carprofen is a dog medicine. It is not approved for cats in the US, and cats should never be given dog NSAIDs.

Side effects to watch for

• Common: reduced appetite, vomiting, diarrhoea or mild lethargy, often in the first days of treatment.
• Stop and call your vet: black or tarry stools, blood in vomit, pale gums, yellowing of the eyes or skin, a sudden change in drinking or urinating, or sudden weakness.

Vets commonly recommend periodic bloodwork when an NSAID is used for months, because the liver and kidneys are the organs most affected. Ask your vet how often they want to check.

Give it with food

Many vets advise giving NSAIDs with food to reduce stomach upset. Follow the directions on your prescription, and ask whether food is required or only recommended. A dog that will not eat should not be given the medicine without asking the vet first.

Long-term use

Long-term carprofen is common for chronic arthritis, but it is a decision to make with a vet, not a default. Ask whether bloodwork is needed before starting and at intervals while your dog is on it. Do not stop or change the dose abruptly without asking, because the underlying pain can return. Keep a note of any new symptoms and bring it to each visit.

For some dogs, the vet may suggest reviewing the plan at set intervals, such as every few months, to check that the pain is still controlled and the medicine is still the right choice.

Carprofen compared with other pain medicines

Carprofen is one of several NSAIDs used in dogs. Meloxicam is another common option, and the Meloxicam Dosage Calculator covers its label figures. Prednisone is a steroid rather than an NSAID, and it should not be combined with carprofen unless your vet decides to. The Prednisone Dosage Calculator explains its own label range. For pain that is not from inflammation, your vet may suggest a different class of drug altogether.

Never give human pain relievers

Human ibuprofen, naproxen and aspirin are dangerous for dogs and can cause stomach ulcers and kidney damage even at small doses. Acetaminophen (Tylenol) is also toxic to dogs. If your dog needs pain relief, use a veterinary product prescribed for your dog. The Dog Tylenol Dosage Warning explains acetaminophen in more detail.

Missed doses and storage

Give a missed dose when you remember, unless it is almost time for the next one. Never double up to make up for a missed dose. If you miss more than one dose or are unsure, call your vet. Store the medicine in its original container, out of reach of children and other pets, at room temperature and away from moisture.

Related tools and guides

• Meloxicam Dosage Calculator
• Prednisone Dosage Calculator
• Gabapentin Dosage Chart
• Tramadol Prescription Checker
• Dog Tylenol Dosage Warning
• Toxicity Calculators hub