🐶 💊
Rimadyl (carprofen) is one of the most widely prescribed canine pain medications in the United States, FDA-approved for relieving inflammation and pain from osteoarthritis and post-surgical recovery. This guide presents the official FDA-approved dosing chart, tablet size reference, monitoring requirements, safety warnings, and everything dog owners need to understand — in plain language.
💊 FDA-Approved Dose
4.4 mg/kg Once Daily or 2.2 mg/kg Twice Daily
The FDA-approved dosage of carprofen (Rimadyl) for dogs is 4.4 mg per kilogram of body weight given once every 24 hours — or alternatively, 2.2 mg/kg twice daily (every 12 hours). This equals approximately 2 mg per pound of body weight daily. The twice-daily split dose is often preferred by veterinarians to reduce risk of gastrointestinal upset. This is the total daily dose — not per individual dose at twice-daily dosing.
📋 Available Tablet Sizes
25 mg · 75 mg · 100 mg
Rimadyl is FDA-approved in three scored tablet sizes: 25 mg, 75 mg, and 100 mg — available as chewable tablets and caplets. An injectable form (50 mg/mL) is also available through veterinarians. The scored tablets allow splitting for precise weight-based dosing. Generic carprofen brands (Vetprofen, Novox, Quellin) are also available in the same three sizes. All forms require a veterinary prescription.
🩺 FDA-Approved Uses
Osteoarthritis + Post-Surgical Pain — Dogs Only
Rimadyl is FDA-approved for two indications in dogs only: (1) relief of pain and inflammation associated with osteoarthritis, and (2) control of postoperative pain associated with soft tissue and orthopedic surgeries. It is NOT FDA-approved for cats — long-term use in cats is unsafe. Human NSAIDs (ibuprofen, naproxen, aspirin) are toxic to dogs and must never be substituted.
📊 Rimadyl Dosing Chart by Dog Weight
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FDA-Approved Dosing Formula
The chart below is the official Zoetis Rimadyl dosing chart (zoetisus.com), based on a target dose of 2.0 mg per pound (4.4 mg/kg) once daily. The total daily dose may also be split into two equal doses given 12 hours apart (1.0 mg/lb twice daily). Weight bands and exact tablet assignments match the manufacturer's published reference. Always confirm with your veterinarian — they may adjust the dose based on your dog's individual health status.
| Dog Weight (lbs) | Total Daily Dose* | Once Daily Tablet | Twice Daily (BID) — each dose | Tablet Size Used |
|---|---|---|---|---|
| 5–10 lbs | 25 mg | ½ tablet once daily | ¼ tablet every 12 hrs | 25 mg scored tablet |
| 11–15 lbs | 25 mg | 1 tablet once daily | ½ tablet every 12 hrs | 25 mg scored tablet |
| 16–20 lbs | 37.5 mg | ½ tablet once daily | ¼ tablet every 12 hrs | 75 mg scored tablet |
| 21–30 lbs | 50 mg | ½ tablet once daily | ¼ tablet every 12 hrs | 100 mg scored tablet |
| 31–40 lbs | 75 mg | 1 tablet once daily | ½ tablet every 12 hrs | 75 mg scored tablet |
| 41–60 lbs | 100 mg | 1 tablet once daily | ½ tablet every 12 hrs | 100 mg scored tablet |
| 61–90 lbs | 150 mg | 1½ tablets once daily | ¾ tablet every 12 hrs | 100 mg scored tablet |
| 91–120 lbs | 200 mg | 2 tablets once daily | 1 tablet every 12 hrs | 100 mg scored tablet |
* Target doses based on the Zoetis-published recommended dosage of 2.0 mg/lb once daily. The total daily dose may be administered as 2.0 mg/lb of body weight once daily OR divided and administered as 1.0 mg/lb twice daily (every 12 hours). Source: Official Zoetis Rimadyl Dosing Chart (zoetisus.com), corroborated by rimadyl.com and multiple veterinary references.
⚠️ Important Notes on This Chart
- All doses are approximations based on the FDA formula of 4.4 mg/kg total daily dose. Your veterinarian will prescribe the exact dose appropriate for your dog.
- Never exceed the prescribed dose. Even accidental double-dosing requires an immediate call to your vet. Overdose can cause serious GI, liver, or kidney damage.
- Scored tablets allow splitting. The 25 mg, 75 mg, and 100 mg tablets are all scored. Always use the tablet size your vet prescribes — using a larger tablet scored down is acceptable only when directed by your vet.
- For very small or very large dogs, or dogs with health conditions, your vet may adjust the dose significantly downward from this chart.
- The injectable form (50 mg/mL) is administered by your veterinarian only — not calculated for home use.
Sources: Official Zoetis Rimadyl Dosing Chart (zoetisus.com, confirmed): weight-band dosing 5201310 lbs through 912013120 lbs with specific tablet assignments based on 2.0 mg/lb once-daily target dose. Corroborated by rimadyl.com official dosing chart, cuteness.com, totalvet.com. FDA-approved total daily dose: 4.4 mg/kg (= 2 mg/lb) once daily OR 2.2 mg/kg (= 1 mg/lb) twice daily (DVM360, GoodRx/Dr. Wooten Aug 2025). Tablet sizes 25/75/100 mg scored: FDA NADA 141-053, DailyMed (nlm.nih.gov, confirmed).
💊 Available Tablet Sizes — Quick Reference
25 mg
Scored Tablet
- Best for small dogs (10-30 lbs)
- Can be split in half: 12.5 mg
- Chewable (beef-flavored) or caplet
- Generic: Novox, Vetprofen available
75 mg
Scored Tablet
- Best for medium dogs (40-80 lbs)
- Can be halved or quartered
- Chewable or caplet forms
- Most commonly prescribed size
100 mg
Scored Tablet
- Best for large dogs (90+ lbs)
- Can be split or quartered
- Chewable or caplet forms
- Maximum accidental ingestion risk
🔐 Storage Warning — Chewables Are Highly Palatable
Because chewable Rimadyl tablets are flavored and highly attractive to dogs, accidental ingestion of an entire bottle is a documented risk. Store all carprofen in a tightly closed, childproof and dog-proof container secured inside a locked cabinet. A bottle of 100 mg tablets (up to 240 tablets per bottle) can represent an extreme overdose risk if accessed by a dog. Store at room temperature between 59°F–86°F (15°C–30°C) as directed on the package insert.
Sources: FDA Official Rimadyl Package Insert (confirmed): 25, 75, 100 mg scored caplets. DVM360 (confirmed): injectable 50 mg/mL, chewable tablet palatability and overdose risk. Urban Animal Veterinary Hospital (Jul 2025): chewable palatability increases accidental overdose risk — store securely. VCA Hospitals (confirmed): store 59°F-86°F. Canine Journal (confirmed): three tablet sizes.
📋 10 Key Takeaways — What Every Dog Owner Must Know About Rimadyl
| # | What to Know | The Short Answer |
|---|---|---|
| 1 | The FDA-approved dose is 4.4 mg/kg/day — not per dose | The total daily dose is 4.4 mg/kg. This can be given as a single once-daily dose OR split into two equal 2.2 mg/kg doses 12 hours apart. You cannot give 4.4 mg/kg twice daily — that would be double the approved dose. Many vets prefer the split twice-daily schedule because it may reduce GI side effects by spreading the drug exposure over the day. |
| 2 | Give Rimadyl with food — always | While carprofen can technically be given on an empty stomach, doing so increases the risk of nausea and vomiting. Always give Rimadyl with a small meal or snack to protect the stomach lining. This is especially important for dogs with a history of digestive sensitivity or for long-term use. |
| 3 | Baseline bloodwork is required before long-term use | Before starting Rimadyl for long-term use, your veterinarian should run a baseline blood chemistry panel to screen for pre-existing liver or kidney disease — conditions that dramatically increase side effect risk. Carprofen should NOT be used in dogs with pre-existing liver or kidney disease (Veterinary Partner/VIN, confirmed). Most dogs do not show outward signs of liver or kidney problems until those organs are seriously compromised — only bloodwork reveals it early. |
| 4 | Monitoring bloodwork must continue every 3-6 months on long-term use | VCA Hospitals confirms: for long-term carprofen use, liver enzyme and kidney values should be checked 2-4 weeks after starting, then every 3-6 months throughout therapy. AskAVet (Dec 2025) recommends rechecking labs at 10-14 days after starting. Senior dogs (10+) are particularly more prone to side effects (Wikipedia/Carprofen, confirmed). Blood tests catch organ stress before visible symptoms appear — this monitoring schedule is not optional for safe long-term use. |
| 5 | NEVER give with other NSAIDs, corticosteroids, or certain other drugs | Combining Rimadyl with other NSAIDs (aspirin, meloxicam, etc.) or corticosteroids (prednisone, dexamethasone) dramatically increases the risk of GI ulceration, kidney damage, and internal bleeding. In 9% of all carprofen adverse reactions reported, concurrent corticosteroid use was noted (Veterinary Partner/VIN, confirmed). Also use caution with ACE inhibitors (enalapril/benazepril) — carprofen can reduce their effectiveness and impact kidney blood flow. If on phenobarbital, bile acid monitoring every 6 months is recommended. |
| 6 | Rimadyl is NOT approved for cats — even one dose can be dangerous | Carprofen is FDA-approved for dogs only. Long-term use in cats is unsafe (AskAVet, Dec 2025). The ASPCA Animal Poison Control Center confirms that even one 25 mg tablet is potentially serious in a cat due to their narrow margin of safety with NSAIDs. If a cat has accidentally ingested any Rimadyl, call the ASPCA APCC immediately at 1-888-426-4435. |
| 7 | An idiosyncratic liver reaction can happen with just 1-2 doses | An unpredictable, severe liver enzyme elevation (idiosyncratic hepatotoxicity) occurs in less than 0.05% of dogs (GoodRx/DVM Wooten, Aug 2025). This is not dose-dependent and cannot be predicted by prior health history — it can happen on the first or second dose. This is why monitoring for early signs (loss of appetite, vomiting, lethargy) in the first 72 hours is critical. Report any unusual symptoms to your vet immediately, even on the first day. |
| 8 | Missing a dose — never double up | If you miss a dose, give it as soon as you remember. However, if it is close to time for the next scheduled dose, skip the missed dose entirely and continue with the regular schedule (VCA Hospitals, confirmed). Never give two doses at once to “make up” for a missed dose — doubling the dose can cause serious GI, liver, or kidney damage even in otherwise healthy dogs. |
| 9 | Rimadyl affects several laboratory tests — inform all your vets | Carprofen can affect thyroid levels, liver enzymes, blood cell counts, potassium levels, kidney values, and bleeding times (VCA Hospitals, confirmed). If your dog is being tested for any of these while on Rimadyl, make sure all treating veterinarians know your dog is on carprofen. Failure to disclose this can lead to misinterpretation of lab results and incorrect diagnoses or treatment changes. |
| 10 | Signs of overdose or serious reaction require immediate emergency veterinary care | Emergency signs include: persistent vomiting (more than twice in 24 hours), diarrhea with blood, black tarry stools, coffee-ground vomit, yellowing of gums or eyes (jaundice), excessive thirst or urination, seizures, difficulty walking, collapse, or extreme low energy (GSVS Emergency, May 2025). Any of these require immediate veterinary emergency care. Do not wait to see if symptoms improve. In case of known or suspected overdose, call ASPCA Animal Poison Control at 1-888-426-4435. |
Sources: FDA Official Rimadyl Package Insert (animaldrugsatfda.fda.gov, confirmed): prescribing information, contraindications. DVM360 (confirmed): 4.4 mg/kg daily dose formula, b.i.d. alternative. GoodRx/Dr. Wooten DVM (Aug 2025): FDA-approved dosage, idiosyncratic reaction less than 0.05%. VCA Hospitals (vcahospitals.com, confirmed): give with food, monitoring schedule 2-4 weeks then 3-6 months, missed dose guidance, lab interactions. Veterinary Partner/VIN (confirmed): no pre-existing liver/kidney disease, ACE inhibitor caution, phenobarbital monitoring, 9% adverse reactions with corticosteroids. AskAVet (Dec 2025): not approved for cats. ASPCA APCC: 1-888-426-4435, cat danger. GSVS Emergency Animal Hospital (May 2025): emergency signs. Wikipedia/Carprofen (Dec 2025): senior dogs aged 10+ more prone to side effects. Urban Animal Vet (Jul 2025): concurrent NSAID/steroid risk.
⚠️ Safety Guide — When to Stop and Call Your Vet
🚨
Stop Rimadyl Immediately and Call Your Vet If You See These Signs
The FDA has established guidelines requiring veterinarians to disclose that serious adverse reactions associated with this drug may occur without warning and could, in rare cases, lead to death. Do not wait for symptoms to worsen. Stop the medication and contact your veterinarian immediately if you observe any of the following.
| Sign | What It May Indicate | Action Required |
|---|---|---|
| 🔴 Vomiting (more than twice/24 hrs) | GI irritation, ulceration, possible overdose | Stop medication. Call vet immediately. |
| 🔴 Blood in vomit / coffee-ground vomit | GI bleeding — emergency | Emergency vet care immediately. |
| 🔴 Black, tarry stools | Internal GI bleeding — emergency | Emergency vet care immediately. |
| 🔴 Yellow gums, eyes, or skin (jaundice) | Liver damage — serious emergency | Emergency vet care immediately. |
| 🔴 Seizures or loss of coordination | Neurological effect — emergency | Emergency vet care immediately. |
| 🔴 Collapse or extreme weakness | Severe systemic reaction — emergency | Emergency vet care immediately. |
| 🟡 Decreased appetite / won't eat | Early sign of GI upset or liver stress | Stop medication. Call vet same day. |
| 🟡 Diarrhea (without blood) | GI irritation | Call vet; they may suggest stopping or reducing dose. |
| 🟡 Excessive thirst and/or urination | Kidney stress or early kidney damage | Stop medication. Call vet same day. |
| 🟡 Pale gums | Internal bleeding or anemia | Call vet urgently. |
| 🟡 Lethargy / unusual tiredness | Possible GI, liver, or kidney stress | Monitor closely; call vet if persists over 24 hrs. |
| 🟡 Skin rash, hives, or face swelling | Possible allergic reaction | Stop medication. Call vet same day. |
🐾 Dogs at Higher Risk — Extra Caution Required
- Senior dogs aged 10 and older — generally more prone to side effects from carprofen (Wikipedia, confirmed Dec 2025)
- Dogs with pre-existing liver or kidney disease — carprofen should NOT be used; consult vet for alternative pain management
- Dehydrated dogs — at greatest risk for renal toxicity (FDA Package Insert, confirmed)
- Dogs on diuretics or ACE inhibitors — kidney function monitoring essential
- Dogs on phenobarbital — drug interaction; bile acids testing every 6 months
- Dogs with GI ulcer history — carprofen should not be used if pre-existing GI ulcerations are present
- Dogs with bleeding disorders (Von Willebrand disease) — NSAID antiplatelet effect increases bleeding risk
- Puppies under 6 weeks — safety not established for this age group
- Pregnant or lactating dogs — use not recommended
- Certain breeds with known NSAID sensitivity — discuss with your vet
Sources: FDA Official Package Insert (animaldrugsatfda.fda.gov, confirmed): GI/renal/hepatic adverse events; dehydrated dogs highest renal risk; concurrent diuretic/corticosteroid caution; hypersensitivity contraindication. VCA Hospitals (confirmed): serious adverse reactions may occur without warning, could lead to death. Veterinary Partner/VIN (confirmed): no pre-existing liver/kidney disease; no GI ulcers; puppies less than 6 weeks. GSVS (May 2025): emergency signs. GoodRx (Aug 2025): idiosyncratic hepatotoxicity less than 0.05%. Wikipedia (Dec 2025): senior dogs 10+ higher risk. BestiePaws (Dec 2024): bleeding disorders, Von Willebrand disease, pregnant/lactating dogs.
💊 Drug Interactions — What NOT to Combine
🚫 Absolute Combinations to Avoid
- Other NSAIDs (aspirin, ibuprofen, meloxicam, deracoxib, etc.): Never give with another NSAID. Combining NSAIDs increases risk of GI ulceration/perforation, kidney damage, and abnormal bleeding. If switching from one NSAID to another, a “washout period” of several days to weeks is required — ask your vet.
- Corticosteroids (prednisone, dexamethasone, methylprednisolone, etc.): Absolutely avoid concurrent use. In 9% of all carprofen adverse reactions, corticosteroid co-administration was documented. GI perforations and hemorrhage risk increases substantially.
- Human NSAIDs (ibuprofen, naproxen, Advil, Aleve): These are TOXIC to dogs. Never substitute human pain relievers for Rimadyl under any circumstances.
⚡ Use With Caution — Tell Your Vet About These
- ACE inhibitors (enalapril, benazepril): Used for heart failure or hypertension. NSAIDs interfere with ACE inhibitor effectiveness by reducing kidney vasodilation. Enhanced kidney monitoring required.
- Diuretics (furosemide/Lasix): Dogs on diuretics are at greatest risk for renal toxicity from carprofen. The combination requires careful monitoring and may be contraindicated in some dogs.
- Phenobarbital: Drug interaction — neither medication may work optimally when combined. Bile acids blood test every 6 months recommended if both must be used together.
- Warfarin/blood thinners: NSAIDs have antiplatelet effects that can compound bleeding risk with anticoagulants.
- Aminoglycosides (antibiotics): Overlapping kidney toxicity potential requires caution and monitoring.
- Gabapentin: Some vets combine Rimadyl with gabapentin for pain management — this combination is used in practice but always under veterinary direction only.
Sources: FDA Package Insert (confirmed): concurrent NSAIDs/corticosteroids contraindicated. Veterinary Partner/VIN (confirmed): 9% adverse reports with steroids, ACE inhibitor interaction, phenobarbital monitoring, diuretic caution. AskAVet (Dec 2025): avoid NSAIDs/steroids, caution diuretics/ACE inhibitors/aminoglycosides/warfarin. Urban Animal Vet (Jul 2025): ACE inhibitor mechanism, COX-preferential explanation. Canine Journal (confirmed): gabapentin combination used by some vets. DVM360 (confirmed): overlapping toxicities with certain drugs.
❓ Frequently Asked Questions About Rimadyl
There is no absolute maximum duration — some dogs with chronic osteoarthritis take carprofen safely for years. The key is consistent veterinary monitoring, not a time limit. The safety of long-term use depends entirely on how your dog's body tolerates the medication, which is only measurable through regular bloodwork.
- Short-term use (3-7 days post-surgery): Typically safe for most dogs without pre-existing conditions. Your vet will specify the exact duration.
- Long-term use (arthritis management): Requires baseline bloodwork before starting, recheck at 2-4 weeks, then every 3-6 months. Any dog on long-term medication should have blood chemistry rechecks every 6 months (VCA Hospitals / Veterinary Partner, confirmed).
- Signs that long-term use should be reconsidered: Trending kidney value increases, rising liver enzymes, GI symptoms, or behavior changes — discuss these findings with your vet promptly.
- Senior dogs require more frequent monitoring as renal and hepatic function naturally decline with age.
The goal is to use the lowest effective dose for the shortest duration that adequately manages your dog's pain. Your vet may also recommend combining Rimadyl with joint supplements, physical therapy, or weight management to allow for dose reduction over time.
Sources: VCA Hospitals (confirmed): 2-4 weeks then 3-6 months monitoring schedule. Veterinary Partner/VIN (confirmed): 6-month recheck any long-term medication. Wikipedia (Dec 2025): duration of use increases adverse reaction risk. AKC (Oct 2025): regular blood work especially older dogs.
Yes — the FDA-approved dose is the same for both indications: 4.4 mg/kg once daily or 2.2 mg/kg twice daily, whether being used for osteoarthritis management or post-surgical pain control.
However, there are important differences in how the drug is used in a surgical context:
- Pre-operative injectable use: The injectable form (50 mg/mL) is recommended to be given by the veterinarian approximately 2 hours before surgery to proactively manage postoperative pain. This is a one-time injection administered in the clinic.
- Post-operative oral continuation: Following the injectable dose, oral carprofen (chewables or caplets) is typically continued for 3-5 days post-op, then stopped once acute pain resolves (AskAVet, Dec 2025).
- For arthritis (chronic use): Dosing is ongoing and monitored with regular bloodwork as described.
- Your vet's instructions take priority — post-surgical protocols can vary based on procedure type, your dog's health status, and other medications used during anesthesia.
Sources: FDA Package Insert (confirmed): INDICATIONS include postoperative pain control — soft tissue and orthopedic surgeries. DVM360 (confirmed): injectable recommended 2 hours pre-surgery. AskAVet (Dec 2025): injectable pre-op then oral 3-5 days post-op. FDA NADA 141-053 (confirmed): clinical efficacy for osteoarthritis demonstrated.
Yes — generic carprofen contains the identical active ingredient as Rimadyl and is FDA-approved at the same doses. The main differences are brand name and cost:
- Rimadyl (Zoetis) — the original brand name product
- Novox (Vedco) — generic carprofen, same 25/75/100 mg sizes
- Vetprofen (Vetoquinol) — generic carprofen
- Quellin — another generic formulation
- Carprofen Caplets (Putney) — compounding pharmacy generic
All generics contain the same active ingredient at the same concentrations and use the same dosing chart. Generic versions are typically significantly less expensive than brand-name Rimadyl and are widely available through veterinary pharmacies and mail-order pet pharmacies with a veterinary prescription.
If your dog is currently doing well on one formulation, there is generally no clinical reason to switch — but if you want to reduce costs, ask your vet whether switching to a generic is appropriate for your dog. Some dogs may have preferences for specific flavored vs. unflavored tablet formulations.
Sources: DVM360 (confirmed): generic formulations Vetprofen, Novox, Carprofen Caplets. Canine Journal (confirmed): generic carprofen significantly less expensive. VCA Hospitals (confirmed): brand names listed including Novox, Vetprofen, Quellin, Levafen. FDA NADA 141-053 (confirmed): original NADA for Rimadyl carprofen.
This is a veterinary emergency — act immediately. Do not wait for symptoms to develop. Carprofen overdose can cause serious damage to the GI tract, liver, and kidneys, and the most common sign in overdose cases is vomiting (seen in 78% of overdose cases in ASPCA APCC database).
- Call ASPCA Animal Poison Control immediately: 1-888-426-4435 (available 24/7; a consultation fee may apply). Tell them your dog's weight, the tablet size, and approximately how many were ingested.
- Or call your veterinarian or nearest emergency animal hospital immediately.
- Or call Pet Poison Helpline: 1-855-764-7661 (also 24/7).
- Do NOT induce vomiting without specific veterinary instruction — vomiting induction in some situations can cause additional harm.
- Bring the Rimadyl bottle with you to the vet to show the tablet size and number originally dispensed.
Even a single accidental double dose requires a call to your vet. With 100 mg tablets especially, even moderate overdose is significant in small or medium-sized dogs.
Sources: DVM360 (Toxicology Brief, confirmed): vomiting in 78% of overdose cases; emesis induction guidance. ASPCA APCC (1-888-426-4435, confirmed): primary poison control resource. VCA Hospitals (confirmed): do not double up doses. DogCancer.com (Feb 2024): severe cases — anorexia, vomiting, icterus.
No — never give Rimadyl to a cat. Carprofen is NOT FDA-approved for cats. Long-term use in cats is unsafe (AskAVet, Dec 2025). The ASPCA Animal Poison Control Center has documented that even a single 25 mg tablet of carprofen can be potentially serious in a cat due to their very narrow margin of safety with NSAIDs.
Cats metabolize NSAIDs very differently from dogs. Their liver lacks certain metabolic pathways (particularly glucuronidation) that allow dogs to process carprofen safely. This means even small doses can accumulate to toxic levels quickly in cats.
If your cat accidentally ate carprofen: Call ASPCA Animal Poison Control immediately at 1-888-426-4435. Do not wait for symptoms.
For cats in pain, there are FDA-approved feline pain medications — ask your veterinarian. Never use dog pain medications for cats without explicit veterinary direction.
Sources: AskAVet (Dec 2025): not FDA-approved for cats, long-term unsafe. DVM360 (confirmed): for dogs only, even one 25 mg tablet potentially serious in cat. VCA Hospitals (confirmed): various species noted but dog-specific dosing. ASPCA APCC: 1-888-426-4435.
Carprofen is a propionic acid class NSAID that works by inhibiting enzymes called cyclooxygenases (COX-1 and COX-2). These enzymes produce prostaglandins — chemical messengers that drive inflammation, pain, and fever.
- COX-2 is the “inducible” enzyme — activated by injury or disease, it produces the inflammatory prostaglandins that cause pain and swelling. Inhibiting COX-2 is what gives carprofen its pain-relieving and anti-inflammatory effects.
- COX-1 is the “constitutive” enzyme — always active, it maintains normal prostaglandins that protect the stomach lining and support normal kidney function. Inhibiting COX-1 causes side effects (GI damage, kidney issues).
- Carprofen is relatively COX-2 preferential (not perfectly selective) — meaning it targets the inflammatory enzyme more than the protective one. This is why it has fewer GI side effects than older non-selective NSAIDs like aspirin. COX-2 preferential NSAIDs have reduced GI side effects by approximately 50% compared to non-selective NSAIDs in human studies (Urban Animal Vet, Jul 2025).
After oral dosing, carprofen takes effect in approximately 1-2 hours. The elimination half-life in dogs is approximately 11.7 hours — meaning it takes about 11.7 hours for half the drug to be eliminated. This pharmacokinetic profile supports both once-daily and twice-daily dosing schedules. The drug is more than 99% bound to plasma proteins and is metabolized primarily in the liver, with metabolites excreted mainly in the feces (70-80%) and urine (10-20%).
Sources: FDA Official Package Insert (confirmed): pharmacokinetics — half-life 11.7 hrs, 99%+ protein bound, 70-80% fecal, 10-20% urinary excretion, COX-1/COX-2 mechanism. VCA Hospitals (confirmed): takes effect 1-2 hours. Urban Animal Vet (Jul 2025): COX-2 preferential reduces GI effects ~50%. AskAVet (Dec 2025): COX-2 preferential mechanism described.
🔍 Rimadyl Dosing Guide — Find Your Dog's Information
Select your dog's weight range and your question to get a tailored dosing and care reference. Always confirm with your veterinarian.
🐶 Rimadyl Quick Reference Finder
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📞 Key Contacts — Rimadyl and Canine Pain Management
🔴 ASPCA Animal Poison Control — 24/7
1-888-426-4435
Call immediately for any suspected Rimadyl overdose or accidental ingestion — in dogs or cats. Available 24 hours a day, 7 days a week. A consultation fee may apply. The ASPCA APCC maintains the largest database of animal poisoning cases in the country. Have the bottle and your dog's weight ready when you call.
🔴 Pet Poison Helpline — 24/7
1-855-764-7661
Alternative 24/7 animal poison control service. Staffed by board-certified veterinary toxicologists and pharmacists. A consultation fee applies. For any suspected overdose or toxic exposure, do not wait for symptoms — call immediately. Also useful for questions about drug interactions.
🟢 Zoetis (Rimadyl Manufacturer)
1-888-963-8471
Zoetis product support line for Rimadyl. Use to report adverse drug events, request product information, or obtain the Safety Data Sheet. Mon–Fri 9am–6:30pm ET. Adverse drug events in dogs should be reported to Zoetis and/or directly to the FDA's Center for Veterinary Medicine.
🔵 FDA Center for Veterinary Medicine
fda.gov/animal-veterinary
The FDA regulates veterinary drugs including Rimadyl. Report adverse drug events through FDA's Safety Reporting Portal at fda.gov/safety/medwatch. Original FDA approval documents for Rimadyl (NADA 141-053) and the full package insert are available at animaldrugsatfda.fda.gov — the authoritative source for all prescribing information.
🟡 AVMA — Veterinarian Finder
avma.org
The American Veterinary Medical Association maintains a veterinarian locator at avma.org. Also visit aaha.org (American Animal Hospital Association) to find AAHA-accredited hospitals — the highest veterinary accreditation standard in the U.S. For arthritis specialists, look for veterinarians with DACVIM or DACVS credentials.
🟢 VIN Veterinary Partner
veterinarypartner.vin.com
Veterinary Information Network — the largest online community for veterinarians in the world. Their Veterinary Partner client information site provides peer-reviewed drug information at no cost, including the full Rimadyl/carprofen monograph referenced throughout this guide. Excellent resource for verifying drug information.
Contacts verified March 2026: ASPCA APCC: 1-888-426-4435 (24/7). Pet Poison Helpline: 1-855-764-7661 (24/7). Zoetis product support: 1-888-963-8471 (Mon-Fri 9am-6:30pm ET). FDA Animal Drugs: fda.gov/animal-veterinary, animaldrugsatfda.fda.gov. AVMA: avma.org. VIN/Veterinary Partner: veterinarypartner.vin.com.
✅ Summary — Rimadyl Dosing Chart for Dogs
- FDA-approved dose: 4.4 mg/kg total daily — given once daily or as 2.2 mg/kg twice daily (every 12 hours). Available in 25 mg, 75 mg, and 100 mg scored tablets plus injectable 50 mg/mL.
- Always give with food. Store chewable tablets in a locked, dog-proof container — accidental ingestion of multiple tablets is a documented emergency risk.
- Baseline bloodwork required before long-term use. Recheck at 2-4 weeks, then every 3-6 months. Senior dogs (10+) require especially close monitoring.
- Never combine with other NSAIDs or corticosteroids. Use caution with ACE inhibitors, diuretics, and phenobarbital — inform all veterinarians of every drug your dog takes.
- For any overdose or suspected toxic ingestion: ASPCA APCC 1-888-426-4435 or Pet Poison Helpline 1-855-764-7661, both available 24/7.
- Not for cats — even one 25 mg tablet can be potentially serious in a cat.
- Stop the medication and call your vet immediately if you see: persistent vomiting, blood in stool or vomit, yellow gums or eyes, excessive thirst/urination, seizures, or collapse.
⚕️ Medical Disclaimer
This widget is provided for educational and informational reference only. It does not constitute veterinary medical advice and does not replace your veterinarian's specific instructions for your dog. Rimadyl (carprofen) is a prescription medication — never administer it without a current, valid veterinary prescription and explicit dosing instructions from a licensed veterinarian. All dosing information in this guide is derived from the FDA-approved labeling and peer-reviewed veterinary sources, but individual dogs vary significantly in their response to medication. BestiePaws.com is an independent educational publication not affiliated with Zoetis, the FDA, or any veterinary professional organization.
Primary sources: FDA NADA 141-053 Freedom of Information Summary (animaldrugsatfda.fda.gov/adafda, confirmed): 25/75/100 mg scored caplets, osteoarthritis indication, safe and effective under labeled conditions. FDA Official Rimadyl Prescribing Information (animaldrugsatfda.fda.gov/adafda/app/search/public/document/downloadLabeling/403, confirmed): INDICATIONS (osteoarthritis, postoperative pain), CONTRAINDICATIONS (hypersensitivity), pharmacokinetics (half-life 11.7 hrs, 99%+ protein bound, 70-80% fecal/10-20% urinary excretion), COX-1/COX-2 mechanism, adverse events, drug interactions, dehydration/diuretic/CVD/hepatic renal risk, concurrent NSAID/corticosteroid warning, storage. DVM360 (Toxicology Brief, confirmed March 2026 from dvm360.com): 2 mg/lb (4.4 mg/kg) daily dose, 1 mg/lb (2.2 mg/kg) b.i.d., injectable 50 mg/mL, 78% vomiting in overdose cases, generic formulations, injectable pre-surgical use. GoodRx / Dr. Sarah Wooten DVM CVJ (updated Aug 2025): FDA-approved dosage, idiosyncratic hepatotoxicity less than 0.05%, twice-daily preferred for GI reduction. VCA Hospitals (vcahospitals.com, confirmed): give with food, monitoring 2-4 weeks then 3-6 months, missed dose guidance, lab test interactions, storage 59-86°F, brand names list. Veterinary Partner/VIN (veterinarypartner.vin.com, confirmed): no pre-existing liver/kidney disease, baseline blood chemistry, 6-month recheck, phenobarbital interaction bile acids, ACE inhibitor mechanism, 9% adverse reports with corticosteroids, puppies less than 6 weeks, GI upset less than 2% of dogs. Wikipedia/Carprofen (confirmed Dec 2025): senior dogs 10+ higher risk, blood tests before and during use, half-life 11.7 hrs, 1999 FDA received 6,000 adverse reports. AKC (akc.org, Oct 2025): regular blood work senior and long-term use. GSVS Emergency Animal Hospital (gsvs.org, May 2025): emergency signs — persistent vomiting, bloody stool, jaundice, seizures, collapse. Urban Animal Veterinary Hospital (urbananimalveterinary.com, Jul 2025): COX-2 preferential reduces GI effects 50%, chewable palatability storage warning, concurrent medications. AskAVet (askavet.com, Dec 2025): 4.4 mg/kg start, switch to BID if GI upset, recheck labs 10-14 days, 3-6 months ongoing, injectable pre-op, oral 3-5 days post-op, not for cats. BestiePaws.com (Dec 2024-Mar 2025): standard 2 mg/lb twice daily, bleeding disorders, Von Willebrand, pregnant/lactating dogs. Canine Journal (confirmed): gabapentin combination, FDA disclosure guidelines, prescription required. DogCancer.com (Feb 2024): most severe cases from overdose or NSAID+steroid combination, bloodwork catches issues early. ASPCA APCC: 1-888-426-4435 (24/7). Pet Poison Helpline: 1-855-764-7661 (24/7). Zoetis product support: 1-888-963-8471.