Recognizing and controlling pain in dogs and cats are important parts of companion animal medicine. Nonsteroidal anti-inflammatory drugs (NSAIDs) are a mainstay of pain management, but these drugs can cause side effects, some of which can be serious. Veterinarians are in the best position to inform dog and cat owners about these side effects and should discuss the benefits as well as the risks of an NSAID with their client before prescribing it for a patient.
Dogs are living longer and healthier lives thanks to advances in veterinary medicine and pharmaceuticals. With active lifestyles that extend into advanced age, many dogs are diagnosed with osteoarthritis (OA). FDA has approved several NSAIDs for dogs to control pain and inflammation associated with OA. Additionally, dogs and cats of all ages undergo surgical procedures and FDA has approved several NSAIDs for dogs and two for cats to control postoperative pain and inflammation.
Inflammation—the body’s response to irritation or injury—is characterized by redness, warmth, swelling, and pain in the inflamed area. When cells are damaged, they produce several substances, including prostaglandins. The main mechanism of action of NSAIDs is to mediate the production or function of prostaglandins. However, clinical and experimental data suggest that NSAIDs also reduce inflammation through additional mechanisms of action, but they aren’t fully understood yet.
In the United States, currently marketed NSAIDs approved for dogs and cats include:
|Active Ingredient||Brand and Generic Names||Species|
|Carprofen||Marketed under multiple brand and generic names||Dogs only|
|Deracoxib||DERAMAXX, DOXIDYL*, DERACOXIB CHEWABLE TABLETS*||Dogs only|
|Firocoxib||PREVICOX, FIROX*||Dogs only|
|Meloxicam Injectable||Marketed under multiple brand and generic names||Dogs and cats|
|Meloxicam Oral||Marketed under multiple brand and generic names||Dogs only|
|Robenacoxib||ONSIOR (for a maximum of 3 days)||Dogs and cats|
*Indicates an FDA-approved generic animal drug.
Other NSAIDs are available in the United States for people but have not been approved for dogs or cats. Sometimes there may not be an approved animal drug available in the concentration or formulation needed for a specific patient. However, the Animal Medicinal Drug Use Clarification Act gives veterinarians the same kind of discretionary authority available to physicians, allowing veterinarians, under certain conditions, to prescribe an approved human or animal drug for “extra-label” uses, which are uses not listed on the label. However, a drug’s label does not include any safety and effectiveness information for extra-label uses.
Every year veterinarians prescribe millions of doses of NSAIDs for dogs and cats with good reason—but many side effects occur. As a group, NSAIDs may affect the kidneys, liver, and gastrointestinal tract. Reported side effects in dogs and cats include vomiting, diarrhea, loss of appetite, depression, and lethargy. Most side effects are mild, but some can become serious and require medical care, especially if the drug is not used according to the label. Serious side effects include gastrointestinal ulcers and perforations and kidney and liver problems. Death may result in some cases.
All NSAIDs approved for oral use in dogs and cats come with a Client Information Sheet (also known as the Information for Dog (Cat) Owner Sheet). Veterinarians should give these sheets to pet owners with every NSAID prescription. The Client Information Sheet provides the owner with important safety information in a user-friendly manner regarding potential side effects of the NSAID and when to seek veterinary attention if problems occur. The sheet also includes other valuable safety information and the drug company’s contact information.
Not all side effects can be predicted
As part of the approval process for an animal drug, FDA evaluates information submitted by the drug company to show that the drug meets the agency’s strict standards for safety and effectiveness, is properly manufactured, and is adequately labeled and packaged. This FDA pre-market review is integral to ensuring the drug is safe and effective for a specific use in a specific animal species. However, every drug has the potential for side effects, and sometimes, problems are detected only after approval when the drug is marketed and used in a large population of animals.
NSAID therapy can also unmask hidden disease that was previously undiagnosed due to the absence of apparent clinical signs. Dogs and cats with underlying kidney disease, for example, may experience worsening of their kidney function while on an NSAID. Dogs and cats at greatest risk for developing side effects from NSAID therapy are those that are dehydrated, on concomitant diuretic therapy, have recently been treated with a corticosteroid, or have pre-existing kidney, heart, or liver dysfunction.
If a patient has a side effect to any animal drug, including to an NSAID, FDA encourages the veterinarian to work with the pet owner to report the problem to the drug company. By law, the drug company must submit all reports of problems with an approved animal drug that they receive to FDA.
Advice veterinarians should give to pet owners
Veterinarians are in the best position to advise pet owners on the safe use of an NSAID. Before administering an NSAID to a dog or cat, the veterinarian should recommend blood and urine tests. The results of these tests could be critical in deciding if the drug is safe to use in the patient. If the veterinarian prescribes an NSAID to a dog to control pain and inflammation associated with OA, which is typically a long-term use, regular check-ups and repeated blood and urine tests are recommended to determine if the drug is safe for continued use.
Veterinarians should advise pet owners to always follow the dosing instructions for an NSAID and to never adjust the dose on their own. Due to the risk of side effects, pet owners should always consult their veterinarian before increasing the dose or increasing the frequency or duration of administration. Veterinarians should also inform owners that giving certain prescription or over-the-counter drugs at the same time as an NSAID could be detrimental to a dog’s or cat’s health.
Choosing the right NSAID for dogs
Just as in people, the degree of pain control in response to an NSAID varies between dogs. Because the response is individualized, no one NSAID is considered more effective than another, and because every NSAID can cause side effects, none is considered safer than others.
It’s important to select the best NSAID for each dog. With the many approved NSAIDs available for dogs, the appropriate and careful use of these drugs can provide much-needed pain relief in most patients.
Sometimes, the process of finding the best NSAID for a specific dog can mean switching to another one. Only one NSAID should be administered to a dog at any given time. If at some point, the owner and veterinarian decide to try a different NSAID, a wash-out period is recommended. A wash-out period is a period of time during which the dog does not receive any NSAID. This allows the first NSAID to be completely cleared from the dog’s body before starting the new one. NSAIDs also should not be combined with a corticosteroid.
While postoperative pain is usually acute and short-lived, pain associated with OA is usually chronic and may wax and wane over time. The lowest effective dose should be used for the shortest duration depending on the dog’s response. If the dog seems to improve to the point of not needing the drug, the owner and veterinarian should discuss discontinuing the NSAID.
NSAIDs and cats
In the United States, only two NSAIDs are approved for short-term use in cats to control postoperative pain and inflammation after spays, neuters, and orthopedic surgeries: 1) meloxicam is given as a single subcutaneous (SC) injection before surgery; and 2) robenacoxib is given for a maximum of three days as either an oral tablet or SC injection. No NSAIDs are approved for long-term use in cats. More than one dose (repeated doses) of meloxicam in cats—which is an extra-label use—can cause kidney failure and death, and more than three doses of robenacoxib in cats have not been shown to be safe.
Because of the short-term duration of use, it’s not feasible to switch between NSAIDs in cats. Veterinarians should select the most appropriate NSAID based on their clinical experience and the particular cat.
Good client communication is key
The key to successful treatment with any drug, including an NSAID, is good communication between the veterinarian and client. NSAIDs are only available by prescription because a veterinarian’s expertise is required to determine if such therapy is appropriate for the pet and to monitor the pet’s health while he or she is on the drug. The veterinarian is the most reliable and qualified source of medical information about the pet.
An informed pet owner is the best defense against serious side effects from NSAIDs. Many side effects may be lessened if owners are aware of what to look for. What starts out as a minor problem can readily progress to an emergency. Veterinarians should encourage owners to ask questions and to call them with any concerns. It’s also important that veterinarians follow the directions for use on the NSAID’s label, as this helps minimize side effects.
Veterinarians should advise pet owners to stop administering the NSAID and call them immediately if a side effect is suspected. The veterinarian or owner can even call the drug company (both the label and Client Information Sheet list a toll-free number). Many drug companies offer customer service and technical support for questions or concerns about a drug. If a pet has a side effect from an NSAID, the drug company may talk with the veterinarian and recommend specific tests and treatments.
The labels, including the package inserts and Client Information Sheets, for many of the NSAIDs approved for dogs and cats may be found on the NSAID Labels page of Animal Drugs @ FDA. The labels for all NSAIDs that are approved for animals contain detailed information about the risks of these drugs.