Carprofen for Cats: Dosage and Injection Risks
By Dr. Zubair Khalid, DVM, MS, PhD ·
Carprofen dosage for cats per kg is not something you can calculate at home from a dog's dose. In the United States, carprofen is not approved for cats, and the injectable form has been used by veterinarians only as a single dose in limited situations. Repeated oral dosing in cats carries a real risk of serious harm.
This article is educational and is not a substitute for veterinary diagnosis or treatment.
Quick Answer
- Do not give your cat carprofen tablets at home. There is no safe, owner-managed oral carprofen dose for cats.
- Injectable carprofen has been used by veterinarians as a one-time dose, not as a take-home medicine for cats.
- Cats clear this drug much more slowly than dogs, so repeated dosing can build up to toxic levels.
- If your cat swallowed carprofen, call your veterinarian or a pet poison hotline right away, even if your cat looks fine.
- Safer feline pain options exist, including drugs approved for cats and other NSAIDs your veterinarian selects.
What Carprofen Is and What Veterinarians Use It For
Carprofen is a nonsteroidal anti-inflammatory drug, or NSAID. It reduces pain, swelling, and fever by blocking certain enzymes involved in inflammation. In the United States, carprofen is approved for dogs, not for cats.
Veterinarians still sometimes use a single injectable dose of carprofen in cats around surgery or a painful procedure. This is called extra-label use, and it happens under direct veterinary supervision. It is not the same as sending a cat home with a bottle of carprofen tablets.
The reason for the caution is simple. Cats process NSAIDs differently from dogs. Their livers use different pathways to break these drugs down, and those pathways are easy to overwhelm. A dose that helps a dog can harm a cat.
If your cat has long-term joint pain, your veterinarian has other choices. Feline osteoarthritis is often managed with drugs designed for cats, such as the injectable monoclonal antibody described in this guide to Solensia Injection for Feline Osteoarthritis: Safe Joint Pain Relief Guide. Your veterinarian can also discuss other NSAIDs, gabapentin, or joint support.
How Carprofen Works in a Cat's Body
Carprofen blocks cyclooxygenase enzymes, which are involved in producing prostaglandins. Prostaglandins drive inflammation and pain, but they also protect the stomach lining and help maintain blood flow to the kidneys. Blocking them too much, or for too long, can damage those organs.
The drug stays in the body longer as the dose goes up. In a study of intravenously administered carprofen in goats, the elimination half-life at 0.7 mg/kg was about 44 hours, and the effect of the drug appeared to be prolonged as the dose increased [1]. Goats are not cats, but the finding shows a pattern seen across species: higher doses mean longer exposure.
That long exposure is the core problem for cats. If a cat receives repeated doses, the drug can accumulate instead of clearing. The result can be stomach ulcers, kidney injury, or liver damage.
Carprofen Dosage for Cats Per Kg: Who Decides and How It Is Given
Your veterinarian decides the dose, not a conversion chart
There is no published carprofen dosage for cats per kg that you should use at home. A veterinarian who uses injectable carprofen in a cat calculates a single dose based on the cat's weight, health status, and the procedure being performed. That decision happens in the clinic, with monitoring available.
Do not try to convert a dog's carprofen dose to your cat. Dogs and cats are not small versions of each other when it comes to NSAIDs.
Carprofen injection for cats
Carprofen injection for cats is given by a veterinarian, usually as a single dose. It is not sent home for you to inject. If your cat received an injection at the clinic, ask your veterinarian what was given, how much, and what to watch for over the next few days.
Carprofen tablets for cats
Carprofen tablets for cats are not recommended for home use. This includes the common tablet sizes owners ask about.
If you have leftover carprofen from a dog in the house, store it where your cat cannot reach it. Cats are curious, and a dropped pill is easy to find.
What if you miss a dose?
If your veterinarian somehow sent you home with carprofen for your cat, which is unusual, do not double up after a missed dose. Call your veterinarian for instructions. Never give a second dose to make up for a missed one.
What about a carprofen equivalent for cats?
Owners often search for a carprofen equivalent for cats because they want the same pain relief in a safer form. The closest equivalents are other NSAIDs approved for cats, such as meloxicam at a veterinarian-set dose, or non-NSAID options like gabapentin, buprenorphine, or tramadol. A study of oral tramadol combined with dipyrone in cats after spay surgery used tramadol at 2 mg/kg and dipyrone at 12.5 mg/kg every 12 hours for 5 days, and the combination was evaluated for pain control and safety [2]. That does not mean you should use those drugs on your own. It means your veterinarian has several feline-specific paths to choose from.
For cats with other chronic conditions, pain control has to fit the whole picture. If your cat also has diabetes, for example, review Insulin Glargine for Cats: Feline Diabetes Dose and Glucose Curve and Cat Diabetes: How to Tell If Your Cat's Insulin Dose Is Too Low before adding any new medication.
Side Effects of Carprofen in Cats
Cats can have a bad reaction to an NSAID even at a dose a veterinarian chose. Cats can also develop NSAID poisoning if they take too much of the medication [3]. Signs can be life-threatening when the dose is high [3].
| Side effect | How common or serious | What to do |
|---|---|---|
| Vomiting, diarrhea, reduced appetite | Common early signs, can signal stomach irritation | Call your veterinarian the same day |
| Lethargy or hiding | Common, but can be an early sign of organ stress | Call your veterinarian the same day |
| Black or tarry stools, vomiting blood | Serious, suggests stomach bleeding | Emergency visit now |
| Increased thirst and urination | Serious, can signal kidney problems | Emergency visit now |
| Yellow gums, skin, or eyes | Serious, suggests liver injury | Emergency visit now |
| Seizures, collapse, trouble breathing | Life-threatening | Emergency visit now |
Clinical signs of NSAID poisoning include stomach and intestinal problems, kidney problems, and neurologic signs, and life-threatening signs can occur if the dosage is high [3]. Do not wait for your cat to look sick before calling for help.
Who Should Not Take Carprofen and What Interacts With It
Cats with kidney disease, liver disease, stomach ulcers, bleeding disorders, or dehydration should not receive carprofen. Very young kittens, pregnant or nursing cats, and cats already on another NSAID are also poor candidates.
Drug interactions matter. Carprofen should not be combined with another NSAID, with steroids such as prednisolone, or with blood thinners. If your cat takes a steroid for an immune condition, review Prednisolone for Cats: Feline Safe Steroid Dose and Autoimmune and tell your veterinarian about every medication and supplement your cat receives.
Some cats need injectable vitamins or other supportive care during illness. If your cat is on a schedule for Vitamin B12 Injections for Cats: Cobalamin Deficiency and Dosing Schedule, mention that too. A complete medication list helps your veterinarian avoid a dangerous mix.
Overdose: When to Call a Veterinarian or Poison Control
Call for help immediately if your cat ate carprofen, even one tablet, and even if your cat seems normal. Signs can take hours to appear, and early treatment works better than waiting.
Call your veterinarian first. If they are closed, call a pet poison hotline. Have the tablet strength, the number of tablets, and your cat's weight ready. Do not induce vomiting unless a veterinarian tells you to.
If your cat received an injection at a clinic and then shows vomiting, lethargy, or appetite loss at home, call the clinic that gave the injection. Report the timing and the signs.
Limitations and When to Contact a Veterinarian
This article cannot tell you the right dose for your cat. Every cat needs an individual assessment by a veterinarian who can examine your cat, review bloodwork, and weigh the risks.
Contact your veterinarian the same day if your cat vomits, has diarrhea, stops eating, or seems more tired than usual after any NSAID.
Go to an emergency clinic now if you see black stools, blood in vomit, yellow gums or eyes, increased thirst and urination, seizures, collapse, or trouble breathing. These signs suggest organ injury and need immediate care.
Schedule a routine visit if your cat has ongoing pain and you are relying on leftover medication. Your veterinarian can build a safer plan.
Frequently Asked Questions
Can I give my cat carprofen tablets?
No. Carprofen is not approved for cats in the United States, and home oral dosing is not considered safe. Even a single tablet can be too much for a cat. Ask your veterinarian for a feline-appropriate pain plan instead.
Is carprofen injection for cats safer than the pills?
A single injectable dose given by a veterinarian is a different situation from repeated oral doses at home. The risk rises with repeated dosing because the drug clears slowly in cats. Any injectable use still requires direct veterinary supervision.
What is the carprofen equivalent for cats?
There is no direct equivalent you can swap in at home. Veterinarians choose from other NSAIDs approved for cats or from non-NSAID pain drugs such as gabapentin, buprenorphine, or tramadol. The right choice depends on your cat's health and the type of pain.
What happens if my cat eats a carprofen 25mg or 100mg tablet?
That is an overdose and needs immediate veterinary care. Call your veterinarian or a pet poison hotline right away, even if your cat looks fine. Do not wait for symptoms, because serious signs can develop hours later.
How long does carprofen stay in a cat's system?
It depends on the dose and the individual cat. In one species, the elimination half-life at a low intravenous dose was about 44 hours, and higher doses prolonged the drug's effect [1]. That slow clearance is one reason repeated dosing is risky in cats.
Related Articles
- Solensia Injection for Feline Osteoarthritis: Safe Joint Pain Relief Guide
- Prednisolone for Cats: Feline Safe Steroid Dose and Autoimmune
- Insulin Glargine for Cats: Feline Diabetes Dose and Glucose Curve
- Cat Diabetes: How to Tell If Your Cat's Insulin Dose Is Too Low
- Vitamin B12 Injections for Cats: Cobalamin Deficiency and Dosing Schedule
- Onsior Robenacoxib for Cats: Feline NSAID Safe Dosing Protocol
- Carprofen for Cats: Side Effects and Safety
- Novox (Carprofen) for Cats: Is It Safe?
- Aspirin for Cats: Dosage, Risks, and Side Effects
References
- Pharmacokinetics of Carprofen Administered Intravenously at Different Doses in Goats. Veterinary sciences, 2025.
- Analgesic efficacy of oral tramadol-dipyrone combination in cats undergoing ovariohysterectomy. Frontiers in veterinary science, 2026.
- Nsaids for Cats. Pet Poison Helpline.