Carprofen for dogs (Rimadyl): uses, side effects, safety

Carprofen is a prescription anti-inflammatory painkiller made for dogs. It is sold as Rimadyl and under generic brand names including Novox, Vetprofen and Carprieve. Vets prescribe it for the pain and stiffness of arthritis and for pain after surgery, and for many older dogs it makes a clear difference to how they move.

It is also a drug that needs respect. It can upset the stomach and, less often, harm the liver or kidneys, so the vet decides whether your dog can take it, sets the dose and checks blood tests along the way.

What is Rimadyl for dogs?

Rimadyl is the original brand of carprofen. Carprofen is a non-steroidal anti-inflammatory drug, or NSAID, the same broad family as ibuprofen in people, but developed and tested for dogs. It works by blocking the chemicals that drive inflammation, which reduces swelling, pain and fever.

Vets use it for:

• Osteoarthritis, including the arthritis that follows hip or elbow dysplasia. See our guide to arthritis in senior dogs.
• Pain after surgery, both soft-tissue operations and orthopedic ones.

It controls pain and inflammation. It does not repair a joint or slow arthritis down, which is why vets pair it with weight control, sensible exercise and changes at home.

How it is given

Carprofen comes as caplets and flavored chewable tablets given by mouth at home, and as an injection given at the clinic, usually around surgery. Vets often suggest giving it with food, which can reduce stomach upset.

The dose depends on your dog's weight, age, kidney and liver function and other medicines, and only the prescribing vet can set it. Give exactly what the label says. Do not give extra on a bad day, split it differently or carry on after the course has ended without asking.

The chewable tablets are flavored to be appealing, and dogs have eaten whole bottles. Store it where no pet can reach it.

How fast does Rimadyl work?

Carprofen is absorbed quickly, and many dogs are visibly more comfortable within a few hours of the first dose. For long-standing arthritis the full benefit can take longer to show, commonly several days to a couple of weeks, as the inflammation settles and the dog starts moving more freely.

If you see no improvement in the time your vet told you to expect, tell the clinic. Do not raise the dose yourself.

Side effects of carprofen

Most dogs take carprofen without problems. When side effects happen, the stomach and gut are the most common site, and the liver and kidneys the most serious. Serious side effects can appear with little warning and, in rare cases, have been fatal, which is why the signs below matter.

A rare, unpredictable liver reaction has been reported, most often in the first few weeks of treatment. It is one reason vets recheck blood tests soon after a dog starts.

The signs to stop for

If your dog vomits, stops eating, has diarrhea, passes black or bloody stool, develops yellow gums or eyes, or seems suddenly dull or unsteady, do not give the next dose and call your vet the same day. Problems caught early are much easier to treat.

Does carprofen make dogs sleepy?

Carprofen is not a sedative. Some dogs sleep more soundly once their pain is under control, which is a good sign if they are also eating well and brighter when awake.

Lethargy is also a listed side effect. A dog that is flat, uninterested in food or hard to rouse is not just resting. Stop the medicine and phone the vet.

What carprofen must not be mixed with

Most of the serious harm from NSAIDs comes from combinations. Carprofen should never be given alongside:

• Another NSAID. That includes other dog anti-inflammatories such as meloxicam, deracoxib, firocoxib and grapiprant.
• A steroid, such as prednisone, prednisolone or dexamethasone, in tablet or injection form.
• Human painkillers. Ibuprofen, naproxen, acetaminophen (paracetamol) and aspirin can seriously harm or kill dogs on their own, and with carprofen the risk of stomach ulcers, bleeding and kidney failure is higher still.

When a dog switches from one of these to another, vets leave a gap between them, called a washout period. How long depends on the drugs involved, and the vet sets it. If your dog was given anything else for pain in the last couple of weeks, including a single aspirin, say so before the first dose.

Other medicines call for extra care and sometimes extra monitoring, among them some heart and blood pressure medicines, diuretics, certain seizure medicines and anything else that is hard on the kidneys or liver. Give the vet a complete list, including supplements. Our page on what you can give a dog for arthritis pain covers the options to raise with your vet and the ones to avoid.

Dogs who may not be able to take it

• Dogs that have reacted badly to carprofen or another NSAID before
• Dogs with stomach or intestinal ulcers, or a history of them
• Dogs with kidney or liver disease. See kidney disease in senior dogs
• Dogs with bleeding or clotting disorders
• Dogs that are dehydrated, vomiting, off their food or have low blood pressure
• Dogs with heart disease, depending on the medicines they take
• Pregnant, nursing or breeding dogs

The vet weighs these risks against the pain and may choose a different medicine or closer monitoring.

Never give a dog's carprofen to a cat. Cats are far more sensitive to NSAIDs, and the canine tablets are not made for them.

Carprofen for older dogs: the blood tests

Older dogs are the ones most likely to need carprofen and the ones most likely to have kidneys or a liver that are quietly below par. That is why vets usually ask for:

• Blood tests, and often a urine test, before starting, to check liver and kidney function and give a baseline
• A recheck in the first weeks, to catch an early reaction
• Regular rechecks during long-term use, at intervals the vet sets for your dog

Between tests, your part is to watch appetite, thirst, stool and energy, and to make sure your dog always has water. If your dog stops eating or drinking, gets a stomach bug or becomes dehydrated for any reason, ask the vet before giving the next dose.

Many senior dogs do well on the lowest dose that keeps them comfortable. Vets often reach that by adding other measures: weight loss, physical therapy, joint injections or other pain medicines. Our guide to managing arthritis in older pets covers the home side.

Tramadol vs Rimadyl

They are different kinds of drug. Carprofen is an anti-inflammatory. Tramadol is an opioid-type pain medicine that has no effect on inflammation. Studies have questioned how well tramadol works on its own for arthritis pain in dogs, and it is usually an add-on, not a replacement.

Vets sometimes prescribe the two together, or use another pain medicine for a dog that cannot take an NSAID. That is the vet's decision. Do not give a human tramadol prescription to a dog.

Novox vs Rimadyl

Novox is a generic carprofen. It contains the same active ingredient as Rimadyl and is prescribed for the same uses. Products can differ in form, flavoring and price. If you are supplied a different brand from last time, check that the strength on the label matches what your vet prescribed.

Is carprofen the best NSAID for dogs?

There is no single best dog anti-inflammatory. Several NSAIDs are approved for dogs, with broadly similar benefits and risks, and individual dogs do better on one than another. The vet chooses based on your dog's age, blood results and other medicines. What matters more than the name is one dog-specific NSAID at a time, at the dose prescribed, with monitoring.

Missed dose, double dose or a chewed bottle

If you miss a dose, call the clinic and ask what to do. Do not give two doses together to make up for it.

If your dog has had an extra dose, has got into the bottle, or another pet has eaten the tablets, call your vet, an emergency clinic or an animal poison control line straight away. Do not wait for signs. Early treatment makes a large difference with NSAID overdoses.

Questions to ask the vet

• Does my dog need blood and urine tests before starting, and when should they be repeated?
• Should I give it with food?
• How soon should I see a difference, and how will we judge whether it is working? Our list of signs of pain in senior pets can help you track it.
• Is it safe with my dog's other medicines and supplements?
• What should I do if my dog skips a meal or has an upset stomach?
• What else can we do so my dog needs less medicine?

Call the vet today if

Stop the carprofen and call your vet the same day if your dog:

• Vomits or has diarrhea
• Eats much less or refuses food
• Passes black, tarry or bloody stool, or vomits blood
• Has yellow gums, skin or whites of the eyes
• Drinks or urinates far more or less than usual
• Is unusually tired, weak, wobbly or behaving strangely
• Develops itchy, red or sore skin

Go to an emergency clinic now if your dog has pale gums, collapses, has a seizure, has swallowed more than the prescribed dose, or was given carprofen together with another anti-inflammatory, a human painkiller or a steroid.

This page is general educational information about carprofen, not veterinary advice, and it does not endorse any brand. Whether carprofen is suitable for your dog, the dose and the monitoring it needs are decisions for the veterinarian who prescribes it. Never give it without a prescription for that dog, never combine it with other painkillers unless your vet has directed it, and never give a dog human pain medicine.