Metacam is a brand-name anti-inflammatory painkiller (meloxicam) used in cats exclusively as a single injectable dose before surgery. It controls pain and inflammation after orthopedic procedures, spay surgeries, and neutering. Unlike in dogs, where Metacam can be given repeatedly as an oral liquid, its use in cats is tightly restricted because repeated doses have been linked to sudden kidney failure and death.
How Metacam Works
Metacam belongs to a class of drugs called NSAIDs, similar in concept to ibuprofen or naproxen in humans. It reduces pain and swelling by blocking enzymes called COX-1 and COX-2 that your cat’s body uses to produce inflammation. In cats, meloxicam inhibits both of these enzymes. COX-2 suppression, which drives the pain relief, lasts up to about four hours after a dose, while COX-1 suppression persists for roughly 24 hours. That broad enzyme suppression is part of why cats are more vulnerable to side effects than dogs.
What It’s Approved For
The FDA has approved only the injectable form of Metacam for cats, and only as a single, one-time dose given by a veterinarian before surgery. The approved uses are controlling postoperative pain and inflammation from orthopedic surgery, spay (ovariohysterectomy), and castration.
The oral suspension of Metacam is approved for dogs but not for cats. The FDA labeling explicitly states: do not give oral Metacam to cats after the single injectable dose. No additional injectable or oral doses should follow.
The FDA’s Black Box Warning
Metacam carries the most serious type of safety warning the FDA issues for animal drugs. The boxed warning states that repeated use of meloxicam in cats has been associated with acute kidney failure and death. The FDA arrived at this warning after identifying numerous cases of cats developing sudden kidney failure after receiving more than one dose.
This is a critical distinction from how the drug is used in dogs. Dogs can safely take Metacam daily for chronic conditions like osteoarthritis. Cats cannot. Any use beyond the single pre-surgical injection is considered off-label, and the FDA has flagged it as dangerous.
Side Effects to Watch For
Even after a single approved dose, some cats experience side effects. In a clinical study of 72 cats receiving the meloxicam injection, about 8% developed elevated markers of kidney stress (blood urea nitrogen levels that rose above normal after treatment), and 12.5% showed post-treatment anemia. The most common reactions owners may notice include vomiting, diarrhea, decreased appetite, lethargy, and behavioral changes.
More serious complications reported after the drug reached the market include kidney failure (marked by elevated creatinine and phosphorus levels), gastrointestinal bleeding, and depression. Death has been reported as an outcome of these reactions. Transient pain at the injection site has also been noted in some cats.
Cats at Higher Risk
Certain cats face greater danger from any NSAID, including Metacam. Cats that are dehydrated, have existing kidney, liver, or heart problems, or have recently been treated with a corticosteroid (such as prednisolone) are at the highest risk for serious side effects. Cats on diuretic medications are also more vulnerable. Your veterinarian should know about all medications and health conditions before administering Metacam.
Combining Metacam with other NSAIDs or corticosteroids increases the risk of gastrointestinal ulcers, perforations, and kidney damage. These drugs should never be given together or in close sequence.
Why Vets Sometimes Prescribe It Off-Label
Despite the FDA’s warnings, some veterinarians in certain countries (particularly in Europe, Australia, and Canada) prescribe very low doses of oral meloxicam for cats with chronic pain from conditions like osteoarthritis. In those regions, regulatory agencies have approved low-dose oral meloxicam for longer-term feline use under close veterinary monitoring, including regular blood work to check kidney function.
In the United States, this remains off-label. If your vet recommends ongoing meloxicam for your cat’s chronic pain, they’re making a clinical judgment that the benefits outweigh the risks for your specific cat. This typically involves the lowest possible dose and frequent kidney function testing. It is not something to attempt on your own, and you should never give your cat a dog-formulated Metacam product or adjust dosing without veterinary guidance.
What This Means Practically
If your cat is scheduled for surgery, your vet may administer a single Metacam injection beforehand to manage post-surgical pain. That one dose is the full extent of approved feline use. You will not be sent home with an oral follow-up prescription of Metacam the way a dog owner might be. Your vet will likely use a different pain management approach for your cat’s recovery at home.
If you find leftover Metacam oral suspension prescribed for a dog in your household, never give it to your cat. The concentration is formulated for dogs, and even a single oral dose in a cat falls outside FDA-approved use. Cats metabolize this drug differently than dogs, and what seems like a small amount can cause irreversible kidney damage.