Are NSAID Pain Relievers Dangerous for Your Dog?

One of the most common and useful class of medications available to veterinarians are the non-steroidal anti-inflammatories (NSAIDs). These treat pain and inflammation, and the evidence for their safety and effectiveness is robust (12). Like all medications that have any meaningful benefits, NSAIDs do have potential side effects. However, these are well-characterized, and in most cases with proper dosing and monitoring, NSAIDs can be used safely to treat pain in dogs and in cats.

Unfortunately, NSAIDs are also one of the most heavily demonized medications available, particularly by those who are critical of  science-based medical therapies or promote alternative medicine approaches. Despite the evidence for the safety of NSAIDs, and the successful use of these drugs to reduce suffering in tens of thousands of pets, some critics would have us believe they are pure poison and inevitably cause injury or death. The many alternatives recommended often have little or no evidence to show they are as safe or as effective as NSAIDs. The reality is that there are few other oral pain medications that have been demonstrated to work safely in dogs and cats, and the push for alternatives to NSAIDs has often led to widespread use of drugs that either don’t work (e.g. tramadol) or that we haven’t yet tested adequately to know if they work or not (e.g. CBD, gabapentin). 

I have reported on the safety and efficacy of NSAIDs several times in the past. It is clear from abundant studies that these drugs are very effective for pain, certainly the best oral analgesic we have for dogs and often a good choice for cats as well (34567). In terms of safety, one review found that the rate of adverse events was very low, with no significant difference in the rate of adverse events between the NSAID and placebo when placebos were used. Out of 1589 dogs in the studies reviewed, only 1 experience a severe reaction requiring hospitalization for treatment.

A more recent systematic review found that adverse effects were reported at rates from 0% to as high as 37.5% of dogs. However, the drugs, study characteristics, and patient populations different widely, so it was not possible to directly compare particular drugs or studies. 

Interestingly, when the highest quality studies were considered (randomized, placebo-controlled clinical trials), no difference in adverse effects was detected between dogs receiving NSAIDs and those on placebo. Though it is clear that such side effects do, of course, occur in some dogs on NSAIDs, and while real clinical patients are likely to respond differently than research subjects, this at least suggests that worries about common and severe harm from these medications are not justified.

Other evidence, including trials used to gain FDA approval, show that dogs on NSAIDs can experience minor problems, such as self-limiting vomiting and diarrhea, or potentially more severe problems such as stomach bleeding, worsening of pre-existing kidney disease, or liver failure. However, the rates of these problems are extremely low, and they must be balanced against the life-limiting pain caused by arthritis, the clear efficacy of NSAIDs in relieving this pain, and the great deal of uncertainty about the safety or benefit of alternative treatments.

There has recently been an increase in concerns about NSAID safety, instigated in part by Dr. Karen Becker, a prominent advocate for alternative therapies whom I have discussed here many times, and Rodney Habib, a social media influencer who misrepresents himself as a pet health expert. This centers on a new study that seems, at first glance, to support the notion that NSAIDs are dangerous and commonly cause patient harm. However, the reality is, as always, more complex and nuanced.

Mabry, K., Hill, T. and Tolbert, M. K. (2021) ‘Prevalence of gastrointestinal lesions in dogs chronically treated with nonsteroidal anti-inflammatory drugs.’, Journal of veterinary internal medicine. J Vet Intern Med. doi: 10.1111/jvim.16057.

This study involved comparing the findings of video capsule endoscopy (VCE) in dogs taking NSAIDs with dogs not on these medications and looking for signs of injury to the lining of the stomach or intestines. VCE is a procedure in which a dog swallows a very small automated camera that takes pictures of the gastrointestinal tract as it passes through and is eventually retrieved from the feces. It is a relatively new procedure, and while it is a useful way to visualize the GI tract, there is limited information available on what is normal or abnormal in different patient populations.

The study compared VCE images from 12 dogs who had been taking an NSAID for at least 30 days with the findings from 11 dogs evaluated for gastrointestinal disease who were not on this kind of medication. Two investigators assessed the pictures taken for signs of erosions, small defects in the lining of either the stomach or small intestines. NSAIDs can cause these erosions, as well as deeper and more serious lesions known as ulcers, so it would not be surprising to see some in a through look at the inside of the GI tract, and this is what the study found.

Of the 12 dogs on NSAIDs, 9 (75%) had erosions in the stomach and 6 (50%) in the small intestine, with 83% of the dogs having erosions identified in one or the other part of the system. This was compared to 3/11 (27%) of the control dogs not taking NSAIDs who had erosions on VCE examination. This finding might be disturbing if we could conclude that this means NSAIDs are harming 83% of the patients taking them. This is not however an appropriate conclusion, nor is it what the authors of the study are claiming.

The most important thing to bear in mind when looking at this study is that none of the dogs taking NSAIDs had any clinical symptoms associated with the medicine. No vomiting, no weight loss, no diarrhea, no loss of appetite, absolutely no sign that the erosions seen on VCE had any meaningful effects. This contrasts from the very real orthopedic pain these dogs had, which is why they were taking NSAIDs in the first place. 

Apart from the important fact that the erosions seen by VCE didn’t cause any apparent symptoms, there are some other reasons to be skeptical of the significance of these findings. The dogs taking NSAIDs were not evaluated prior to starting the medications, so it is unknown how many of them might have already had erosions not related to the drugs. Almost 30% of the dogs not taking NSAIDs also had erosions on VCE, so it is likely that some of the dogs in the NSAID group would have had them before starting the medication. This is also a very small study, and there were differences in the breeds and health status of the dogs in the two groups that limit our ability to generalize the results to other patient populations.

The authors of the study were clearly aware of the limitations of the findings and also the potential for misinterpretation and misuse of their results. They state very clearly in the paper:

The clinical relevance of our findings is unclear, and we do not recommend withholding NSAIDs if dogs require pain control, or that all NSAIDs be administered concurrently with gastroprotectants. Lesions were subclinical in all dogs, and none were known to later develop clinical signs of ulceration…Ultimately, the presence of lesions might not have clinical relevance if none of the affected dogs ever go on to develop clinical signs of ulceration.

While it is worth investigating the issue of asymptomatic GI tract erosions associated with NSAIDs and identifying when these might cause actual clinical symptoms, how we might prevent them, and other ways in which this technique could help us make NSAID use even safer, this study does not undermine the already robust evidence that NSAID use in dogs and cats has significant benefit and rarely causes serious harm. Discontinuing NSAID treatment to avoid lesions detectable only by VCE and which caused no symptoms would mean taking away effective pain treatment for no clinical benefit, and this is not in the best interests of these dogs. 

Replacing NSAIDs with other treatments that have far less evidence to show safety and effectiveness is also not a reasonable response to these findings. Dr. Becker and others frequently recommend unproven supplements and alternative therapies for pain that have not been shown to work. The assumption that these treatments are safer than NSAIDs or can partially or fully replace these medications is simply another unproven claim, a roll of the dice based on opinion, anecdote, and little or no reliable scientific evidence.

The goal of all medical treatment is to maximize patient well-being and minimize risk, though such risk can never be completely eliminated. At this time, the evidence is clear that NSAIDs are still the most effective oral pain reliever we have for dogs and cats, and their risks when properly used are small compared to their benefits. Other and better treatments are certainly need, and these will eventually be developed through the slow, rigorous process of scientific research. It is unfortunate that some vets and other proponents of alternative therapies will use these findings to frighten pet owners and encourage them to reduce their use of proven safe and effective pain relief in favor of untested or unrpoven alternatives.

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10 Responses to Are NSAID Pain Relievers Dangerous for Your Dog?

  1. Kathryn says:

    Can you comment on T-Relief? The bottle says homeopathic, but lists actual dosages of the ingredients.

    Needless to say, I took my cat off it when I found out what it was and dumped my vet when told “Don’t believe everything you read on the internet” when i called her on the homeopathy part.

  2. skeptvet says:

    Looks like the ingredients are listed with a “x-factor” in front of them, which is a way of referring to homeopathic dilution. These are mostly low-potency (i.e. not very diluted) ingredients (3x, for example, means diluted by a factor of 10 three times), so there is some chance of some residual chemicals in the final product, though likely not enough to do much, for good or ill.

  3. Jazzlet says:

    I’d go further than you and say that witholding effective NSAIDs for ineffective alternatives is cruel. But I’ve had two dogs who were kept mobile and happy with an NSAID, both of whom would have had to be put down years earlier without that effective pain control, so I am definitely in favour of the use of NSAIDs when appropriate – anecdotal obviously.

  4. M A says:

    Fear is the most powerful weapon, once instilled near impossible to remove. It is tragic that members of vet proffession use their credentials to spread it, resulting in scores of pets living in pain. These people are not real vets IMO. They should be called for their actions

  5. Jen Robinson says:

    I’m on an NSAID for arthritis of the hip myself. (Helps, but hardly a miracle). The doc prescribed omeprazole to counter possible side effects. Is the equivalent available for dogs?

  6. skeptvet says:

    Omeprazole can be used in dogs and does raise gastric pH (unlike famotidine, which works in humans but not much in dogs). However, it is unclear if this is useful for preventing gastric ulcers from NSAID use, which is related to blood flow in the stomach rather than acidity of stomach contents. Here is the statement on this issue from the expert consensus guideline on gastroprotectants:

    It is common to prescribe PPIs in patients at risk for upper GI injury from nonsteroidal anti?inflammatory drugs (NSAIDs), but PPIs can alter the SI microbiome, increasing the risk of injury to the intestinal epithelium caused by NSAIDs. This effect is acid?independent and unrelated to gastric mucosa injury caused by NSAIDs. Inhibition of intestinal cyclooxygenase 1 and 2 (COX?1, COX?2) enzymes injures the SI mucosa. Enterohepatic recycling of NSAIDs likely plays a role whereby high concentrations of NSAIDs in bile are secreted into the duodenum in close proximity to the major duodenal papilla. Some of the most serious intestinal lesions in dogs caused by NSAIDs occur in this region.10, 95, 96 Small intestinal injury may be caused by increased numbers of gram?negative facultative anaerobic bacteria that flourish in the SI of patients treated with PPIs. Lesions are characterized by loss of villi, erosions, and multifocal ulcers distributed throughout the small bowel. Anemia also may occur. Whereas some bacteria play a protective role against intestinal mucosal injury by NSAIDs, the intestinal dysbiosis arising from PPI administration increases the risk of NSAID?induced intestinal injury.94 Administration of antibiotics or probiotics may mitigate injuries caused by this drug combination,94 but such studies have not been conducted in dogs or cats.

  7. Danny says:

    My senior rescue dog has hip dysplasia, arthritis, and a hyperextended tendon, for which he has had two surgeries in the little more than a year that I’ve had him. I suspect that he was hit by a car years ago. He currently takes Metacam. Due to the current shortage of Metacam, my primary care vet has recommended Galliprant. It seems promising, from what I’ve read so far on this new medication. What are your thoughts on Metacam v. Galliprant? Thanks for your help!

  8. skeptvet says:

    Meloxicam (Metacam) is a well-established traditional NSAID with lots of published data on safety and efficacy. There are. both risks and benefits, as with all treatments but, dosed and monitored properly,in most dogs it works well. Grapriprant (Galliprant) is a new NSAID with a different mechanism of action. There is clinical trial evidence showing good safety and efficacy, but the amount of research is fairly limited as it is a new drug. It is FDA licensed for use in dogs. I have used both often and both seem to work well and have limited adverse effects, but the overall evidence is less robust for Galliprant since it has not been around as long. I think both are reasonable choices in your situation, with the usual need for monitoring.

  9. Lisa says:

    Our vet took our greyhound off Metacam a few months ago following GI issues that led to a presumptive diagnosis of IBD (ultrasound, but no biopsy as yet). She struggles with pain and reduced mobility (no surprise given her background – still racing at 7 and she turns 10 tomorrow) so has been put on gabapentin, amantadine and paracetamol (also still on omeprazole). Having read this piece and the gabapentin article I am left wondering how we can best help her. I know our vet wants to control pain as much as possible, and reluctantly stopped the metacam on advice from an internal medicine colleague, but I am wondering whether I should be discussing the current prescriptions with her? It seems as though there isn’t a lot else that does have solid evidence of being effective, but that isn’t a good reason for giving Velvet drugs that are maybe not helping in the way we hope (I find it very hard to tell!). Not expecting a solution, but would be interested in your thoughts 🙂

  10. skeptvet says:

    Definitely, a tough situation. IBD, and more importantly the medications she will likely need if this is confirmed are reasonable justification for stopping NSAIDs, so I don’t think it wrong to do so. The evidence for gabapentin and amantidine is poor, which doesn’t mean they don’t work, just that we haven’t tested them well enough to know for sure. acetaminophen probably is helpful, though it has be dose very carefully since the dosing range is very narrow. The most important thing is whether you feel like her discomfort is meaningfully affective her quality of life, and then balancing that against the risks and uncertainties of the treatment options. We often try things with poor evidence in tough situations (e.g. fish oil, CBD), and that’s not inappropriate so long as we think carefully about the uncertainties and potential risks and benefits.

    As you say, I can’t give you an answer, but I would definitely keep talking to your vet about the level of discomfort you see and the options for treatment. It is sometimes helpful to assess her symptoms in a regular and consistent way to evaluate when therapies are or are not helping. Here are some tools you could use to do this.

    Good Luck!

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