Journal Scan: How common are NSAID side effects in dogs?

Why they did it

The true incidence of adverse effects associated with the nonsteroidal anti-inflammatory drugs (NSAIDs) used in veterinary medicine is unknown. The authors of this report conducted a systematic literature review to critically evaluate the quality of evidence surrounding NSAID-related adverse event data in dogs.

What they did

The authors conducted a review of NSAID studies conducted between 1990 and 2012 and ranked studies according the Food and Drug Administration scientific data ranking system for quantity and consistency. Strength of evidence was classified as high, moderate, low, or extremely low and was based on how applicable the conclusions were to the target population.

What they found

The researchers included 35 research studies and 29 clinical trials that evaluated 14 NSAIDs overall. Studies evaluating carprofen, firocoxib, and meloxicam had the highest strength of evidence. Deracoxib, robenacoxib, and ketoprofen were assigned moderate strength of evidence based on the small number of patients in these studies. Etodolac was assigned a low strength of evidence rating. Adverse effects were reported in 35 of the total studies and trials (55%), but the number of affected dogs relative to treated dogs was not reported in all cases, and only three studies reported a power analysis related to adverse effects.

Side effects included vomiting, diarrhea, anorexia, lethargy, and melena. In 39% of the studies the incidence of adverse effects was not statistically different between treated and control dogs, but most studies were not designed to evaluate NSAID safety and were conducted in healthy research dogs. The researchers found that the strength of evidence regarding the incidence of adverse events was variable among studies and between individual NSAIDs.

Take-home message

While the actual incidence of adverse effects related to NSAIDs could not be determined from this review, “estimates for the most serious adverse effects suggest that they occur at a very low frequency.” It is important to note, however, that most of the studies were conducted in young, healthy dogs and may not accurately represent the population that would most likely be treated with NSAIDs (e.g. older dogs with underlying illness).

Monteiro-Steagall BP, Steagall PVM, Lascelles BDX. Systematic review of nonsteroidal anti-inflammatory drug-induced adverse effects in dogs. J Vet Intern Med 2013;27:1011-1019.

Link to abstract: onlinelibrary.wiley.com/doi/10.1111/jvim.12127/abstract