Side Effects in the Digestive Tract (Stomach and Intestines)
Nonsteroidal anti-inflammatory drugs can cause side effects in the digestive tract both directly and indirectly. The direct effects are related to the drugs’ physical properties. Many NSAIDs become trapped in the stomach and are slightly acidic, so they directly irritate the stomach lining.
The indirect effects are due to NSAIDs either preventing the body from making prostaglandins or blocking the protective activity of these substances. Remember, prostaglandins also protect the lining of the stomach and intestines. When fewer prostaglandins are produced or some of their activity is blocked, the entire digestive tract may be more prone to damage. This can lead to ulcers and perforations (holes) in the stomach and intestines.
Giving an animal two NSAIDs at the same time, or an NSAID with a steroid such as prednisone, increases the risk of side effects in the digestive tract and should be avoided.
During periods of decreased blood flow to the kidneys—such as when an animal is dehydrated, under anesthesia, or has kidney disease—prostaglandins cause the arteries going to the kidneys to open. This helps keep blood flowing to these vital organs.
Because NSAIDS prevent the production of prostaglandins or block some prostaglandin activity, these drugs can reduce blood flow to the kidneys, possibly causing kidney damage and leading to sudden-onset kidney failure.
NSAIDs should be used cautiously in animals that may already have kidney disease or other conditions that cause reduced blood flow to the kidneys, like dehydration and shock. If an NSAID is used around the time of surgery, intravenous (IV) fluids are generally recommended before, during, and after anesthesia to maintain blood flow to the kidneys, hopefully reducing potential kidney complications.
The side effects of NSAIDs on the liver can be divided into two categories: (1) dose-dependent; and (2) dose-independent.
As the name implies, dose-dependent side effects are related to the dose—the higher the dose of the NSAID, the worse the side effects and the liver damage. This type of liver damage is typically caused by a massive NSAID overdose, such as a dog eating an entire bottle of his owner’s ibuprofen. (The ASPCA Animal Poison Control Center receives hundreds of calls each year involving dogs and cats that accidentally eat nonsteroidal anti-inflammatory drugs.)
Remember to keep all medications—for both people and pets—in a secure location out of reach of children, dogs, cats, and other animals to prevent accidental ingestion or overdose.
Dose-independent side effects can occur at any dose of an NSAID, even the correct one, and is an unpredictable reaction where the patient’s liver has an abnormal sensitivity to the medication. Most liver damage that is associated with an NSAID occurs within the first three weeks of starting the medication.
NSAIDs should be used cautiously in animals that may already have liver disease.
The table below lists the currently marketed FDA-approved NSAIDs for dogs and cats. All of them are available by a veterinarian’s prescription only. No over-the-counter NSAIDs for dogs and cats are FDA-approved. Any NSAID marketed for dogs or cats online or in a pet store without the need for a prescription from a veterinarian is an unapproved animal drug, meaning FDA has not reviewed information about the drug. An unapproved animal drug may not meet the agency’s strict standards for safety and effectiveness and may not be properly manufactured or properly labeled.
| 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 |
| Grapiprant | GALLIPRANT | Dogs only |
| Meloxicam | Marketed under multiple brand and generic names | Dogs (injectable and oral) and cats (injectable only) |
| Robenacoxib | ONSIOR (for a maximum of 3 days) | Dogs and cats |
*Indicates an FDA-approved generic animal drug.
Several NSAIDs are FDA-approved for dogs to control pain and inflammation associated with osteoarthritis; and to control pain and inflammation after soft tissue and orthopedic surgery. [Orthopedic pertains to bones and muscles; soft tissue is everything else. Repairing a dog’s torn ACL (anterior cruciate ligament) in her knee is an orthopedic surgery; removing a ball from a dog’s stomach is a soft tissue surgery.]
Most of the NSAIDs for dogs listed in the above table are approved for both uses (for osteoarthritis and after surgery) with two exceptions: (1) robenacoxib (sold under the brand name ONSIOR) is only approved to control pain and inflammation after soft tissue surgery and should be given for a maximum of 3 days; and (2) grapiprant (sold under the brand name GALLIPRANT) is only approved to control pain and inflammation associated with osteoarthritis.
All NSAIDs for dogs are given either by mouth (oral) or by injection.
Because osteoarthritis is a long-term (chronic) condition that doesn’t go away, a dog may be on an NSAID for a long time. The lowest dose that provides adequate pain control should be used. Owners should always consult with their veterinarian before adjusting the dose, especially before increasing it.
For a dog taking an NSAID long-term for osteoarthritis, it’s good to check his or her liver and kidney function by doing blood tests before starting the medication and then repeating the blood tests on a regular basis.
Only two NSAIDs are FDA-approved for cats: meloxicam (sold under several brand and generic names) and robenacoxib (sold under the brand name ONSIOR).
Meloxicam is approved for cats as a one-time-only injection to control pain and inflammation after spaying, neutering, and orthopedic surgery. The injection is given under the cat’s skin before surgery.
Robenacoxib is also approved for cats to control pain and inflammation after spaying, neutering, and orthopedic surgery. The medication should be used once daily for no more than three days and is available as either a tablet given by mouth or an injection given under the cat’s skin.
Currently, no NSAIDs are approved for long-term use in cats. Cats are especially sensitive to the side effects of NSAIDs. More than one dose (repeated doses) of meloxicam in cats can cause kidney failure or death, and more than three doses of robenacoxib have not been shown to be safe in cats.
How can I tell if my dog is in pain?
With obvious injuries or after surgical procedures, it can reasonably be assumed that a dog will experience pain. Although the signs may be subtle, careful observation will often reveal signs of pain in most dogs. Most dogs experiencing pain alter their behavior in some way. A dog may be reluctant to climb stairs, jump into the car, show decreased activity, or resist being handled or picked up. Subtle signs may be our only clue that the dog is hurting.
Arthritic pain is common in older dogs. Anyone who has witnessed an older dog struggle to rise or be unable to stand after lying down can imagine the discomfort these dogs must endure.
Other signs of pain include (but are not limited to):
What’s the difference between spaying and neutering?
Spaying and neutering refer to surgical procedures that cause your pet to be unable to produce puppies. In many places, both surgeries may be referred to as neutering or being fixed.