Pain Medications

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Pain due to arthritis or after surgery can be treated with multiple drugs. Each drug class treats the pain in different ways and may have possible side effects associated with therapy. In general, it is a good idea to only use medications at the prescribed dosage, for the pet it is prescribed, and as directed. Many medications interact with each other and may cause an increased risk of side effects when combined (such as steroids and NSAIDs). Therefore, please contact your veterinarian prior to adding any medications (including over the counter) for your dog’s pain management.

At CSU, we have a veterinarian available 24 hours, and we would rather you contact us before adding any medications that you are unsure about. You may also email us at with questions or concerns. This website is intended to provide you with basic information about the most common pain medications we prescribe at CSU.

Non-Steroidal Anti-Inflammatory Drugs (NSAIDs)

Non-steroidal anti-inflammatory drugs are one of the most commonly used and most effective drug in the treatment of pain due to arthritis or after surgery in dogs and cats. Rimadyl®, Metacam®, Dermaxx®, and Etogesic® all belong to this class of drugs. These drugs act by inhibiting inflammatory substances called prostaglandins (PGEs), which cause pain, inflammation, and fever. Hence they are called “anti-inflammatory” but their main purpose is pain control (inflammation is how pain starts). Side effects can occur, with the most common being gastrointestinal (GI) disturbance (symptoms include vomiting, diarrhea, bloody or dark colored feces) from minor GI-ulcers. It is important to recognize these symptoms early since stomach or GI leakage from perforation can result if the medications are continued – which can be life-threatening. There is also risk of acute liver and/or kidney failure with all NSAIDs. The risk of developing a liver problem after NSAID administration in a healthy dog is small (1:10,000). However, if it is encountered it may be fatal and hence we recommend testing your pet for liver or kidney problems before starting NSAIDs. Blood tests before administration of NSAIDs cannot always predict a liver or kidney reaction but if a significant dysfunction is identified we do not recommend administering an NSAID. We recommend to monitor kidney and liver function if your pet is on these drugs for a prolonged period of time. Generally, we advise blood tests be performed prior to NSAID therapy, 7-10 days after administration and then every six months.

​Important things to consider when giving NSAIDs:

  • This drug should be given with food and water. If your dog is not interested in eating or drinking, please do not give the medication. Monitor water intake and urination as an indicator of kidney infection.
  • Never give Aspirin to your pet – there are much safer options than this drug for animals. Aspirin given together with any other NSAID dramatically increases the risk of adverse effects.
  • Never administer NSAIDs at a higher dose than the prescribed dose (this will increase the risk of adverse effects).
  • Stop the NSAID at the first signs of gastric upset, nausea, lack of appetite, vomiting or diarrhea and give your veterinarian a call to discuss the next steps.
  • Do not mix NSAIDs (i.e. two different NSAIDs) and do not give over-the-counter NSAIDs (eg. ibuprofen, naproxen).
  • Do not give NSAIDs with steroids like dexamethazone, prednisolone, Vetalog or Depomedrol.
  • Do not give NSAIDs in patients with known impaired gastrointestinal, kidney, cardiovascular, liver, or coagulation functions.
  • Do not give NSAIDs with Enalapril or other ACE inhibitors, Lasix, or with nephrotoxic drugs like aminoglycoside antibiotics or psychotropic drugs (Prozac, Clomiclam).
  • Contact a veterinarian immediately if your dog eats more than the prescribed amount of the dispensed tablets.


Tramadol is a synthetic opioid that does not share the common side effects of most natural opioids. Tramadol can be used separately or in combination with non-steroidal anti-inflammatory drugs and can also be used in cats. Side effects are considered rare but may include constipation, and mild sedation or bizarre behavior (if you notice these side effects, please reduce the dose by half). This drug has a bitter taste and likely will need to be hidden something tasty to prevent rejection. Unfortunately, Tramadol is much less efficient at controlling pain than NSAIDs.


This drug is useful in treating neuropathic pain (the burning and tingling sensations that come from damaged nerves) by an unknown mechanism. The drug has also been used successfully as an adjunct treatment for arthritis therapy. Response to therapy can take days to weeks as the drug reaches therapeutic concentrations. Side effects are few and include sedation or ataxia. Please do not discontinue Gabapentin abruptly. Please contact your vet if you notice any of these side effects.


This drug acts by modulating the pain response by antagonizing receptors in the central nervous system (N-methyl-d-aspartate (NMDA) receptor). Amantadine is considered an adjunct to the analgesic drugs by dampening or resetting spinal cord receptors so that other analgesics can work more effectively. Therefore, it is most commonly given together with NSAIDs. Side effects include diarrhea, flatulence and agitation. Please contact your vet if you notice any of these side effects.