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Stop Previcox and call your vet the same day if your dog has black or tarry stool, vomits (especially blood), stops eating, drinks or urinates much more or less than normal, seems unusually tired or wobbly, or has yellow gums, skin or eyes. Never give Previcox with another NSAID (Rimadyl, Metacam, Galliprant, Deramaxx, aspirin) or a steroid such as prednisone. Keep it away from puppies: overdoses in puppies under seven months have been linked to deaths.
The short answer: Previcox is firocoxib, an FDA-approved, highly COX-2-selective NSAID for arthritis pain in dogs and for up to three days of pain after surgery. The label dose is 5 mg/kg (2.27 mg/lb) once a day, given as 57 mg or 227 mg chewable tablets split into quarters, so a 50 lb dog takes about half a 227 mg tablet. It works about as well as carprofen: in a 218-dog head-to-head trial, 92.5% of firocoxib dogs and 92.4% of carprofen dogs improved, with a bigger drop in lameness on firocoxib. Its half-life is only about 7.8 hours, not the "30+ hours" quoted online. And "COX-2 selective" does not mean gut-proof: in a 2022 hospital review of dogs whose stomach or gut perforated on a single NSAID at the label dose, 5 of 18 were on firocoxib and none on carprofen. Bloodwork before and during treatment is the safeguard.
By Marc Brannigan and Natalie Mondine, co-founders of HempMy Pet · Published November 7, 2026 · Last reviewed November 7, 2026. We have grown and bottled full-spectrum hemp for pets on our own Colorado farm since 2016. We are not veterinarians — everything below comes from the published veterinary studies, consensus guidelines and drug labels listed at the end.
What Previcox Is
Previcox is the brand name for firocoxib, a "coxib" NSAID made by Boehringer Ingelheim. Like other NSAIDs it blocks the cyclo-oxygenase (COX) enzymes that make the prostaglandins behind pain and inflammation. Firocoxib is more than 350-fold selective for COX-2, the inflammation-driving enzyme, over COX-1, which protects the stomach and kidneys. That selectivity is the main selling point, though the label itself notes that its clinical significance "has not been established."
In dogs it is FDA-approved for two things: the pain and inflammation of osteoarthritis, once daily as needed, and pain after soft-tissue or orthopaedic surgery, for up to three days, starting about two hours before surgery. The horse version of the same drug is Equioxx; we cover that in Equioxx for horses.
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Previcox Dose for Dogs by Weight
The label dose is 2.27 mg/lb (5 mg/kg) once daily, with or without food. The tablets are double-scored and the label says to calculate the dose in quarter-tablet steps, so the practical dose is the nearest quarter of a 57 mg or 227 mg tablet:
| Dog weight | Exact label dose | Nearest quarter-tablet |
|---|---|---|
| 10 lb (4.5 kg) | 23 mg | ½ × 57 mg (28.5 mg) |
| 15 lb (6.8 kg) | 34 mg | ½ × 57 mg (28.5 mg) |
| 25 lb (11.3 kg) | 57 mg | 1 × 57 mg (57 mg) |
| 40 lb (18.1 kg) | 91 mg | 1½ × 57 mg (85.5 mg) |
| 50 lb (22.7 kg) | 114 mg | ½ × 227 mg (113.5 mg) |
| 75 lb (34.0 kg) | 170 mg | ¾ × 227 mg (170.25 mg) |
| 100 lb (45.4 kg) | 227 mg | 1 × 227 mg (227 mg) |
| 125 lb (56.7 kg) | 284 mg | 1¼ × 227 mg (283.75 mg) |
Calculated from the label dose of 2.27 mg/lb. Rounding to quarter tablets means the real dose often lands a little above or below 5 mg/kg; your vet decides which way to round. For illustration only.
- Dogs under 7 lb (3.2 kg) cannot be dosed accurately with these tablets, according to the current label.
- Puppies under seven months: the label warns that doses above 5 mg/kg have been associated with serious adverse reactions, including death. Use exactly what your vet prescribes.
- Split tablets should be used within 30 days.
- Missed dose: give it when you remember unless the next dose is nearly due. Never give two doses close together to catch up.
How Fast Does Previcox Work, and How Long Does It Last?
From the FDA label: in fasted dogs, blood levels peak about 1 hour after a dose; giving it with food delays the peak to about 5 hours and lowers it, without changing the total amount absorbed. Only about 38% of an oral dose reaches the bloodstream, and the elimination half-life is about 7.8 hours. It is still given once a day, because that is the dosing the trials tested.
In practice, some dogs look more comfortable within a day or two. The trials judged it over one to two weeks: in a one-year study, 82% of owners reported improvement by day 15. If there is no change after two weeks at the prescribed dose, talk to your vet rather than giving more.
Does Previcox Work? What the Dog Trials Show
- Versus carprofen (218 dogs, 2006): in a double-blind trial, 92.5% of firocoxib dogs and 92.4% of carprofen dogs improved on the vets' overall score. Firocoxib reduced lameness significantly more, and owners rated it slightly higher (96.2% versus 92.4%).
- Versus etodolac (249 dogs, 2006): firocoxib was at least as good, and better for lameness at a trot, pain on manipulation and range of motion by the end of the study.
- 1,002 dogs in US practices (2006): vets rated 93% and owners 91% of dogs improved after about 40 days; 2.9% stopped because of stomach or gut side effects. This was an open study run with the manufacturer, with no comparison group.
- After surgery: in the label's field studies, dogs on Previcox needed rescue pain medication significantly less often than dogs given a sham pill.
One honest caveat. The osteoarthritis trials compared firocoxib with other NSAIDs rather than with a placebo, so they show it works about as well as the established drugs, not how much better it is than doing nothing. A 2009 systematic review still rated the evidence for firocoxib, carprofen and meloxicam as strong, the best of any arthritis option in dogs.
Previcox for the Long Haul
A 52-week study gave 39 arthritic dogs firocoxib every day. Of the 25 that finished, 96% were rated improved by their owners, and 12 of them kept improving in lameness between day 90 and day 360. But 14 of the 39 dogs did not finish, and 5.1% stopped because of stomach or gut side effects, so the headline figure describes the dogs that did well enough to stay on it. The label's 180-day safety study in healthy Beagles found no treatment-related problems at the normal dose.
How long can a dog take Previcox? The label says "as needed," with "the lowest effective dose for the shortest duration." Many dogs take it for months or years. That is reasonable with a baseline blood panel and urinalysis, a recheck after the first few weeks, and then regular rechecks. Many vets check every 6 to 12 months.
Previcox Side Effects in Dogs
| Side effect | How common | What to do |
|---|---|---|
| Vomiting, diarrhea, poor appetite | The most common; 2.9% stopped for GI effects in the 1,002-dog study | Call your vet if it lasts more than a day or two |
| Black, tarry stool, vomiting blood | Uncommon but serious: possible ulcer or bleeding | Stop and call your vet the same day |
| Lethargy, wobbliness | Uncommon; listed in post-approval reports | Call your vet |
| More or less drinking and urinating | Uncommon: possible kidney effect | Stop and call your vet |
| Yellow gums or eyes, raised liver values | Rare: possible liver effect | Stop and call your vet |
Source: PREVICOX FDA label, including post-approval reports listing GI perforation and ulceration, kidney failure, liver failure, seizures and other events, with deaths reported; Ryan 2006.
Will Previcox make my dog sleepy? Not usually. It is not a sedative. Lethargy appears among post-approval reports, so a dog that is suddenly dull or tired on it should be checked rather than assumed to be resting.
The COX-2 Myth: Selective Is Not the Same as Safe
Coxibs were designed to be gentler on the stomach, and in short healthy-dog studies firocoxib looks clean: 28 days at the label dose caused no stomach lesions on endoscopy in six healthy dogs, and three days of firocoxib, deracoxib or meloxicam made no difference to the gut lining in another study. Real-world data are less tidy.
A university teaching hospital reviewed 30 dogs that came in with a perforated stomach or duodenum after NSAID use between 2007 and 2020. Eighteen had received a single NSAID at the labelled dose: 8 on meloxicam, 5 on firocoxib, 3 on deracoxib and 2 on piroxicam. None were on carprofen alone, even though carprofen accounted for 70.6% of NSAID prescriptions among the referring vets, versus 7.8% for firocoxib. It is a single hospital and shows association, not cause, but it is a good reason not to treat any NSAID as automatically gut-safe. The other dogs in the series had been given two NSAIDs, an NSAID plus a steroid, or an overdose, the classic avoidable causes.
Previcox vs Rimadyl, Metacam and Galliprant
| Drug | What it is | How it compares with Previcox |
|---|---|---|
| Rimadyl (carprofen) | COX-2-preferential NSAID, once or twice daily | Equal overall improvement in a 218-dog trial; Previcox reduced lameness more. Most prescribed; no single-drug perforations in the 2022 hospital series |
| Metacam (meloxicam) | COX-2-preferential NSAID, once-daily liquid | Liquid dosing suits small dogs better; strong placebo-controlled evidence |
| Galliprant (grapiprant) | Blocks one prostaglandin receptor (EP4), not the COX enzymes | Designed to spare the stomach and kidneys; often chosen for higher-risk dogs |
| Librela (bedinvetmab) | Monthly antibody injection against nerve growth factor | Not an NSAID; an option for dogs who cannot take one |
| Gabapentin | Nerve-pain drug | Not anti-inflammatory; commonly given alongside Previcox |
Your vet picks based on your dog's kidneys, liver, stomach history, size and other medicines.
Are Previcox and Rimadyl the same? No. Both are NSAIDs for the same conditions, but they are different molecules with different selectivity and dosing, and they must never be given together. Switching from one to the other needs a washout gap. The label says to "consider appropriate washout times" when switching NSAIDs or moving from a steroid to an NSAID, so ask your vet how many days.
Drugs Not to Combine With Previcox
- Any other NSAID, including aspirin, and any steroid such as prednisone or dexamethasone.
- With caution: diuretics such as furosemide, ACE inhibitors and other drugs that affect the kidneys. The label names dehydrated dogs, dogs on diuretics and dogs with kidney, heart or liver disease as the highest-risk group.
- Usually fine alongside: gabapentin, amantadine and trazodone, which are not NSAIDs. Your vet will still want the full list, including supplements. See our hemp and dog medications guide.
Where Hemp Fits
We make hemp oil, so here is the honest version. The strongest canine evidence for CBD is for osteoarthritis pain, the same condition Previcox is approved for, but nothing supports stopping a prescribed NSAID and switching to hemp. Where it fits is alongside your vet's plan:
- In our own 90-day study overseen by veterinary pain specialist Dr. Robin Downing, dogs stayed on their existing prescriptions while our oil was added, and every medication change was made by the supervising vet.
- Both NSAIDs and CBD can raise liver values, so a dog on both needs bloodwork. Every published figure is in our guide to hemp side effects in dogs, and the doses used in the dog trials are on one page.
Full-spectrum extract in cold-pressed hemp seed oil, grown and bottled on our own Colorado farm: the oil used in our 90-day joint study, where dogs stayed on their prescriptions. Not a replacement for Previcox. Tell your vet before adding it to an NSAID plan. Third-party tested every batch. $99
Shop 1,000mg Hemp Seed Oil → See the StudyWhat Is the Safest Anti-Inflammatory for Dogs?
There is no single safest one, and the 2022 perforation data are a reminder that selectivity on paper does not settle it. The safest choice is the one matched to your dog: the right drug for their kidneys, liver and stomach history, at the lowest dose that works, never combined with another NSAID or a steroid, and monitored with bloodwork. For dogs who cannot take NSAIDs, Librela is an option, and weight loss, controlled exercise, rehab, ramps and non-slip floors help every arthritic dog. Never use human painkillers; our guide to what you can give a dog for pain explains why.
Questions to Ask Your Vet
- What is my dog's dose in mg/kg, and are we rounding the tablet up or down?
- Do we need bloodwork and a urine test before starting, and when is the recheck?
- Why Previcox rather than carprofen, meloxicam or Galliprant for my dog?
- If we switch NSAIDs, how many days of washout?
- Which signs mean stop and call you?
Frequently Asked Questions
Is Previcox or meloxicam better for dogs?
Neither is clearly better for every dog. Both are FDA-approved NSAIDs with strong evidence for arthritis pain. Previcox is a once-daily chewable that is more COX-2 selective; meloxicam is a once-daily liquid that is easier to dose precisely in small dogs. In a 2022 hospital review of gut perforations on a single NSAID at the label dose, both appeared (meloxicam 8 dogs, firocoxib 5), so selectivity alone does not decide it.
What are the side effects of Previcox?
The most common are vomiting, diarrhea and poor appetite; in a 1,002-dog study, 2.9% stopped because of these. Serious but uncommon effects include stomach or intestinal ulcers and perforation (black or tarry stool, vomiting blood), kidney problems (changes in drinking and urination) and liver problems (yellow gums or eyes). The label's post-approval reports include deaths.
Are Previcox and Rimadyl the same?
No. Both are NSAIDs used for arthritis and post-surgical pain, but Previcox is firocoxib and Rimadyl is carprofen, different molecules with different dosing. In a 218-dog trial, 92.5% of firocoxib dogs and 92.4% of carprofen dogs improved. They must never be given together, and switching between them needs a washout period set by your vet.
How long can dogs take Previcox?
The label allows it once daily as needed for osteoarthritis, and many dogs take it for months or years. A 52-week study found 96% of the 25 dogs that completed it improved. Long-term use needs baseline bloodwork and urinalysis, a recheck after the first few weeks, and regular rechecks, often every 6 to 12 months.
Is Previcox a good painkiller for dogs?
Yes, for inflammatory pain such as arthritis and after surgery. It was at least as effective as carprofen and etodolac in head-to-head trials, with a greater reduction in lameness, and after surgery dogs on it needed rescue pain medication less often than dogs given a sham pill. It is not an opioid and does not treat nerve pain the way gabapentin does.
Will Previcox make dogs sleepy?
Not usually. Previcox is not a sedative, and most dogs are simply more comfortable and active on it. Lethargy and wobbliness do appear in post-approval adverse event reports, so a dog that becomes unusually tired or unsteady should be seen by a vet.
Are firocoxib and Previcox the same?
Yes. Firocoxib is the drug and Previcox is the dog brand, sold as 57 mg and 227 mg chewable tablets. The same drug is sold for horses as Equioxx, in different strengths. Do not give a horse product to a dog or a dog product to a horse unless your vet directs it.
What is the Previcox dose for dogs?
The label dose is 2.27 mg per pound (5 mg/kg) once daily, calculated in quarter-tablet steps of the 57 mg or 227 mg tablets. For example, a 25 lb dog takes about one 57 mg tablet and a 50 lb dog about half a 227 mg tablet. Dogs under 7 lb cannot be dosed accurately with these tablets.
Can dogs take Previcox and gabapentin together?
Generally yes, if your vet prescribes both. Gabapentin is not an NSAID and works on nerve pain, so the two are commonly combined for arthritic dogs. Gabapentin can cause sleepiness, so watch your dog closely for the first few days. Never combine Previcox with another NSAID or a steroid.
How long does Previcox stay in a dog's system?
Firocoxib's elimination half-life in dogs is about 7.8 hours, according to the FDA label, so most of a dose is cleared within about a day and a half. Blood levels peak about an hour after a dose on an empty stomach, or around five hours if given with food.
The Short Version
Previcox (firocoxib) is an FDA-approved, once-daily NSAID for dog arthritis and post-surgical pain at 5 mg/kg (2.27 mg/lb), given in quarter-tablet steps. It works about as well as carprofen, with a greater drop in lameness in one large trial, and dogs have taken it for a year with good results. Being COX-2 selective does not make it gut-proof, so give one NSAID at a time, never with a steroid, leave a washout when switching, and keep up with bloodwork.
Full-spectrum hemp from our own Colorado farm: alongside your vet's plan, not instead of it
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Meloxicam for Dogs · Carprofen for Dogs · Rimadyl Side Effects · Galliprant · Librela · Gabapentin · Arthritis in Dogs · Equioxx for Horses
Marc co-founded HempMy Pet in 2016 with his business partner Natalie Mondine, the company's COO. HempMy Pet breeds its own hemp genetics, grows them on its own Colorado farm, and formulates every batch in-house under human-grade standards — seed to sale, nothing sourced overseas. Every batch is third-party tested and the certificates of analysis are published. More about us.
HempMy Pet ran its own 90-day study of 37 dogs with chronic joint discomfort. Of the 32 that completed it, 30 (93%) showed a benefit, and 94% of owners reported their dog's quality of life had improved. It was overseen by Dr. Robin Downing, DVM, MS of the Downing Center for Animal Pain Management, with Lori Kogan, Ph.D. and Peter W. Hellyer, DVM of Colorado State University's College of Veterinary Medicine & Biomedical Sciences, and published in the Journal of the American Holistic Veterinary Medical Association. Read the methodology.
Why Dr. Downing: in 2005 she became only the third veterinarian in the world credentialed as a Diplomate of the American Academy of Pain Management. She founded the International Veterinary Academy of Pain Management, is a Diplomate of the ACVSMR, a Certified Veterinary Pain Practitioner and a Certified Canine Rehabilitation Practitioner, and was the AVMA's 2020 Bustad Companion Animal Veterinarian of the Year. Read the published paper (PDF).
This article is general information for dog owners, not veterinary advice. It is reviewed and updated as new peer-reviewed evidence is published, and where the evidence is thin or negative we say so.
How We Sourced This Article
Every claim above traces to one of these.
- US Food and Drug Administration / Boehringer Ingelheim. PREVICOX (firocoxib) Chewable Tablets, label: indications, 2.27 mg/lb dose in quarter-tablet steps, 7 lb minimum, puppy warning, washout advice, pharmacokinetics (38% bioavailability, 7.8-hour half-life, 1–5 hour peak), field studies, 180-day safety study and post-approval adverse events.
- Pollmeier M, Toulemonde C, Fleishman C, Hanson PD. Clinical evaluation of firocoxib and carprofen for the treatment of dogs with osteoarthritis. Vet Rec. 2006;159:547–551. PubMed.
- Hanson PD, Brooks KC, Case J, Conzemius M. Efficacy and safety of firocoxib in the management of canine osteoarthritis under field conditions. Vet Ther. 2006;7:127–140. PubMed.
- Ryan WG, Moldave K, Carithers D. Clinical effectiveness and safety of a new NSAID, firocoxib: a 1,000 dog study. Vet Ther. 2006;7:119–126. PubMed.
- Autefage A, Palissier FM, Asimus E, Pepin-Richard C. Long-term efficacy and safety of firocoxib in the treatment of dogs with osteoarthritis. Vet Rec. 2011;168:617. PubMed.
- Pfeifer JM, Levy NA, Carter DL, Beal MW. Gastric or duodenal perforation and secondary septic peritonitis following therapeutic nonsteroidal anti-inflammatory drug administration. J Vet Emerg Crit Care. 2022;32:764–768. PubMed.
- Steagall PV, et al. Evaluation of the adverse effects of oral firocoxib in healthy dogs. J Vet Pharmacol Ther. 2007;30:218–223. PubMed. Also Wooten JG, et al. Am J Vet Res 2009;70:1243–1249, PubMed.
- Sanderson RO, Beata C, Flipo RM, et al. Systematic review of the management of canine osteoarthritis. Vet Rec. 2009;164:418–424. PubMed. Safety review: Monteiro-Steagall BP, et al. J Vet Intern Med 2013, PubMed.
- Veterinary references. FDA, Get the facts about pain relievers for pets · PetMD, Firocoxib.
- Kogan L, Hellyer P, Downing R. The Use of Cannabidiol-Rich Hemp Oil Extract to Treat Canine Osteoarthritis-Related Pain: A Pilot Study. J Am Holist Vet Med Assoc. 2020;58:35–45. Our disclosure: HempMy Pet supplied the hemp extract and reimbursed clinic costs; we had no involvement in any other study cited here.
Spot something that conflicts with your veterinarian's advice? Email support@hempmypet.com and we will correct it.
These statements have not been evaluated by the Food and Drug Administration. Our products are not intended to diagnose, treat, cure, or prevent any disease. This article is general information, not veterinary advice. Never start, stop or change your dog's medication without your veterinarian.
