Calculate the correct Carprofen (Rimadyl) dose for your dog based on body weight.
Dosage Calculator
Enter your dog's weight to calculate the recommended dose.
Calculated Dose
Total daily dose
Per dose (× daily)
Nearest tablet size
Enter your dog's weight above
⚕️ This calculator is for informational purposes only. Carprofen is a prescription-only medication. Always consult your veterinarian before administering any medication to your dog.
Carprofen is a non-steroidal anti-inflammatory drug (NSAID) commonly prescribed by vets to relieve pain, inflammation, and fever in dogs. It is sold under brand names including Rimadyl, Canidryl, and Carprieve.
Standard Dosage Guidelines
The recommended dose of Carprofen for dogs is 4.4 mg/kg once daily or 2.2 mg/kg twice daily. Both protocols deliver the same total daily dose. Your vet will advise on the best schedule for your dog.
Available Tablet Sizes
Carprofen is available in 25 mg, 75 mg, and 100 mg chewable or film-coated tablets. Always use the tablet size closest to the calculated dose to avoid under- or over-dosing.
Important Safety Notes
Never exceed the prescribed dose. Carprofen should always be given with food to reduce the risk of gastrointestinal upset. It is not suitable for dogs with liver or kidney disease, bleeding disorders, or those already on other NSAIDs or corticosteroids. Contact your vet immediately if you notice vomiting, diarrhoea, black stools, or lethargy.
💊 NSAID · COX-1/COX-2 Inhibitor
Carprofen Dosage Calculator for Dogs
Precise carprofen (Rimadyl, Novox, Vetprofen) dosing for dogs by weight, dosing frequency, and indication — covering osteoarthritis, post-surgical pain, and acute musculoskeletal conditions with tablet selection and hepatotoxicity monitoring guidance.
⚠️
Prescription NSAID — veterinary supervision required. Never combine with other NSAIDs, aspirin, or corticosteroids. Obtain baseline bloodwork (ALT, ALP, BUN, creatinine) before starting; recheck every 3–6 months on long-term therapy. Discontinue immediately if vomiting, black stools, jaundice, or lethargy occur.
Carprofen inhibits both COX-1 and COX-2 isoforms of cyclo-oxygenase, reducing prostaglandin synthesis. It has preferential activity toward COX-2 at therapeutic doses. Prostaglandin inhibition reduces inflammation, pain sensitisation at peripheral and spinal levels, and fever. Available in chewable tablets for ease of administration.
Primary Uses in Dogs
Osteoarthritis (most common long-term use), post-operative pain management (especially orthopaedic), fever, and general musculoskeletal pain. One of the most commonly prescribed NSAIDs in dogs globally.
Dosing Quick Reference
Indication
Dose
Frequency
OA pain management
4.4 mg/kg
q24h PO with food
Split-dose protocol
2.2 mg/kg
q12h PO with food
Post-op loading
4.4 mg/kg
Single dose pre/post-op
Common Side Effects
GI upset, vomiting, diarrhoea (most common)
GI ulceration and haemorrhage
Idiosyncratic hepatotoxicity (Labrador Retrievers appear at higher risk)
Renal dysfunction with dehydration or prolonged use
Protein-losing nephropathy (rare)
Monitoring
ALT, ALP, BUN, creatinine at baseline then every 6 months for chronic use. Urinalysis including USG. More frequent monitoring (every 3 months) in Labrador Retrievers or dogs > 10 years old.
⚠️ Labrador Retrievers have a documented higher risk of carprofen-associated idiosyncratic hepatotoxicity — monitor liver enzymes closely. Never combine with other NSAIDs, corticosteroids, or aspirin. Run baseline bloodwork before initiating long-term therapy. Watch for early signs: anorexia, jaundice, dark urine.
What Is Carprofen?
Carprofen (Rimadyl, Novox, Vetprofen, Canidryl) is a propionic acid-class NSAID that inhibits both cyclooxygenase-1 (COX-1) and COX-2 enzymes, reducing prostaglandin synthesis and thereby decreasing inflammation, pain, and fever. While it has some preferential COX-2 selectivity compared to aspirin, it is not a pure COX-2 inhibitor like deracoxib. It was the first NSAID specifically approved by the FDA for long-term use in dogs (1997).
Carprofen is available as 25 mg, 75 mg, and 100 mg chewable (beef-flavoured) tablets, making dose titration convenient across the full weight range from small breeds to giant breeds. It achieves peak plasma concentrations within 1–3 hours of oral administration.
Injectable solution: 50 mg/mL (for intra/peri-operative use by vet clinic)
How to Use This Calculator
Enter your dog’s current body weight in kg or lbs — use lean body weight if obese
Select the dosing regimen: once daily (4.4 mg/kg q24h) or twice daily (2.2 mg/kg q12h) — both are FDA-approved; once-daily simplifies compliance
Choose the tablet strength available (25, 75, or 100 mg)
Select the indication — post-surgical use may differ from chronic OA management
Click Calculate for dose, tablet count per administration, and safety reminders
🧮 Carprofen Dose Calculator
Carprofen Dosing Result
Weight-Based Quick Reference
Weight
q24h dose (4.4 mg/kg)
q12h dose (2.2 mg/kg)
Best tablet
5 kg (11 lbs)
22 mg/day
11 mg × 2
25 mg (½ tablet × 2)
10 kg (22 lbs)
44 mg/day
22 mg × 2
25 mg × 2 once daily
20 kg (44 lbs)
88 mg/day
44 mg × 2
75 mg + 25 mg once daily
30 kg (66 lbs)
132 mg/day
66 mg × 2
100 mg + 25 mg once daily
40 kg (88 lbs)
176 mg/day
88 mg × 2
100 mg + 75 mg once daily
50 kg (110 lbs)
220 mg/day
110 mg × 2
100 mg × 2 + 25 mg once daily
Safety Monitoring Protocol
Timepoint
Tests
Action if Abnormal
Before starting
ALT, ALP, BUN, creatinine, urinalysis
Do not start if significantly elevated; investigate
2–4 weeks after start
ALT, ALP
Discontinue if >3× ULN; assess for hepatotoxicity
Every 3–6 months
Full biochemistry, urinalysis
Dose reduce or discontinue if hepatic/renal changes
Any time — warning signs
Vomiting, diarrhoea, black stools, jaundice, lethargy, polyuria/polydipsia
Discontinue immediately; emergency vet visit
Frequently Asked Questions
Yes — carprofen is FDA-approved for long-term daily use in dogs and is one of the most prescribed chronic pain medications in veterinary medicine. However, long-term use requires regular blood monitoring (ALT, ALP, BUN, creatinine) every 3–6 months to detect hepatotoxicity or renal impairment early. Studies have shown carprofen is well-tolerated long-term in the vast majority of dogs, but individual susceptibility varies, especially in Labrador Retrievers who may be at higher risk of idiosyncratic hepatotoxicity.
Both once-daily (4.4 mg/kg q24h) and twice-daily (2.2 mg/kg q12h) regimens deliver the same total daily dose and are FDA-approved. Once-daily dosing is more convenient and improves owner compliance. Twice-daily dosing distributes the GI load into two smaller doses, which may reduce gastric irritation in sensitive dogs. Clinical efficacy is considered equivalent. Most veterinarians now recommend once-daily dosing for long-term OA management unless the dog has GI sensitivity.
Yes — combining carprofen with gabapentin or tramadol is a common and safe multimodal pain management approach used extensively in veterinary medicine. These drugs work through different mechanisms (carprofen = anti-inflammatory; gabapentin = calcium channel modulator for neuropathic pain; tramadol = opioid/monoamine reuptake). There are no significant pharmacokinetic interactions. This combination is particularly useful for severe OA, disc disease, or cancer pain where a single drug is insufficient.
A washout period of at least 5–7 days (preferably 14 days) is recommended when switching between NSAIDs to reduce the risk of additive GI ulceration and renal toxicity. Never give two NSAIDs simultaneously. If switching from carprofen to meloxicam or vice versa, discontinue carprofen, wait the full washout period, then begin the new NSAID at the lowest effective dose. The washout period also applies when transitioning to or from corticosteroids (e.g., prednisolone).
Yes — Labrador Retrievers appear to have a breed-specific predisposition to idiosyncratic hepatotoxicity from carprofen compared to other breeds. The mechanism is not fully understood but appears immune-mediated rather than dose-dependent. This does not mean carprofen should be avoided in Labradors — it is still widely and safely used in this breed — but closer liver monitoring (every 3 months rather than 6 months) is advisable. Other breeds reported with increased hepatic sensitivity include Dobermann Pinschers and Irish Wolfhounds.
Carprofen is not recommended for puppies under 6 weeks of age. For puppies older than 6 weeks, it can be used for post-surgical pain under veterinary supervision. Long-term use in young growing dogs should be approached cautiously as prolonged NSAID use may theoretically affect bone and cartilage development. For chronic joint conditions in growing dogs (e.g., hip dysplasia), the risk-benefit ratio should be discussed with a veterinary orthopaedic specialist.
References
Plumb DC. Plumb’s Veterinary Drug Handbook, 9th ed. Wiley-Blackwell; 2018.
KuKanich B, et al. The effects of inhibiting cytochrome P450 3A, p-glycoprotein, and gastric acid secretion on the oral pharmacokinetics of methadone in dogs. J Vet Pharmacol Ther. 2008;31(2):142-149.
Johnston SA, Budsberg SC. Nonsteroidal anti-inflammatory drugs and corticosteroids for the management of canine osteoarthritis. Vet Clin North Am Small Anim Pract. 1997;27(4):841-862.
MacPhail CM, et al. Hepatocellular toxicosis associated with administration of carprofen in 21 dogs. J Am Vet Med Assoc. 1998;212(12):1895-1901.