If your dog has been prescribed gabapentin or pregabalin for chronic pain, you might be wondering how these drugs work and whether they are the right choice for your dog. We’ve taken a look at what the peer-reviewed science tells us, and where the gaps remain.
What are these drugs and how do they work?
Gabapentin and pregabalin are gabapentinoids, originally developed as anticonvulsants. They work by binding to a specific area of voltage-gated calcium channels in the nervous system, and this reduces the release of excitatory neurotransmitters that can amplify pain signals. This makes them particularly suited to neuropathic pain (pain arising from the nervous system itself) rather than straightforward inflammatory pain. In people, they are licensed for use in pain associated with diabetic neuropathy, and post-herpetic neuralgia.
Both drugs are used off-label in dogs in the UK, as neither holds a veterinary marketing authorisation for any indication.
What conditions are they used for in dogs?
In veterinary practice, gabapentinoids are used as part of a multimodal pain management approach for neuropathic pain arising from intervertebral disc disease, spinal cord injury, or peripheral nerve damage; Chiari-like malformation and syringomyelia; osteoarthritis where a central sensitisation or neuropathic component is suspected; cancer-associated chronic pain; and post-surgical pain as part of perioperative analgesia (Reader, R., et. al., 2021, Bell, A.M. et al., 2014)
What does the evidence actually show?
Despite being frequently prescribed, the veterinary evidence base is limited in terms of how effective the gabapentinoids are as pain medications.
Gabapentin
Ruel et al., (2020) studied 29 dogs with neuropathic pain treated with gabapentin, gabapentin & meloxicam, or placebo. Compared to baseline, dogs treated with either of the medications showed reduced pain burden, however the pain burden was not different to placebo. The study only employed a treatment time of 7 days, which is likely too short to see effects for many of the drugs used for chronic pain.
In a cross-over study of 33 dogs with Chiari-like malformation and syringomyelia, the investigators found no improvement in raw pain scores with gabapentin (nor another drug, topiramate), but did demonstrate a meaningful improvement in quality of life scores compared to baseline in gabapentin treated dogs (Plessas et al., 2023).
Of 10 dogs treated for lumbosacral disease with prednisolone and tramadol, 5 failed to respond and were administered gabapentin which was reported to be associated with subsequent improvements (Giudice, E. et al., 2019), no placebo group was included.
An abstract presented at a veterinary conference reported that, of 24 dogs recruited to a study utilising gabapentin or tramadol in conjunction with NSAID, 18 completed the study. Both groups showed improvements in weight bearing as measured by a pressure sensitive walkway but a high incidence of side effects was reported (details not given). Again, no placebo group was included (Miles et al., 2020)
Pregabalin
Evidence for pregabalin in dogs is even more limited.
A 2024 study comparing pregabalin to a herbal extract in dogs with cervical neuropathic pain found equivalent pain-relieving efficacy between the two treatment groups, with no placebo control (Petchnamthong et al., 2024).
Sanchis-Mora et al., (2019) performed a blinded placebo controlled crossover study to assess pregabalin combined with NSAID in 8 dogs with Chiari-like malformation, and identified lower pain scores and a reduction in skin sensitivity in the animals during pregabalin treatment.
These findings were supported in a placebo controlled study of 12 dogs with Chiari/syringomyelia (Thoefner, M. S. et al., 2020), although much higher doses were used.
What this means
It is important to be clear about what the limited evidence base does and does not tell us. Absence of robust evidence for efficacy is not the same as evidence that these drugs do not work. They may well be effective for some dogs in some circumstances, and the biological rationale is sound. The problem is that without well-designed randomised controlled trials in dogs, we cannot yet distinguish with confidence which dogs are genuinely benefiting from those who are appearing calmer due to sedation, or whose owners are perceiving improvement because they expect it. Clinical experience, including that of specialists, is a valuable guide but is known to be susceptible to bias.
Safety considerations
Both drugs are generally well tolerated in dogs, and most side effects are dose-dependent and reversible with dose adjustment.
Sedation and lethargy are the most commonly reported side effects with both drugs. This is clinically important: a dog that is quieter and less active after starting gabapentin may appear more comfortable, but may simply be too sedated to express discomfort. Sedation and pain relief are not the same thing, and owners and vets should be alert to this distinction.
Ataxia (unsteadiness and loss of coordination) can occur, particularly at higher doses or on initiation of treatment. Starting at a lower dose and titrating upwards may reduce this risk.
Hepatic disease gabapentin is partially excreted by liver metabolism (Radulovic L et al., 1995), therefore liver dysfuction can lead to accumulation of the drug.
Drug interactions. Both drugs can increase sedation when combined with opioids, tramadol, tricyclic antidepressants, or other drugs acting on the central nervous system. Always inform your vet of all medications your dog is receiving.
Do not stop abruptly. After prolonged use, gabapentin should be tapered gradually rather than stopped suddenly, to avoid rebound effects.
What does this mean in practice?
Both gabapentin and pregabalin are recommended as adjuncts within a multimodal pain management approach by the 2022 American Animal Hospital Association Pain Management Guidelines. They are not intended to be used alone, but alongside other treatments including NSAIDs, physical therapies, and lifestyle modifications.
If your dog is currently taking gabapentin or pregabalin, it is worth asking a few questions at your next appointment.
Is the dog actually responding? Has there been an objective improvement in mobility, engagement, and quality of life, or does the dog simply seem quieter? A structured assessment using a validated pain scoring tool is more reliable than general impression.
Is the dose appropriate? Given the pharmacokinetic considerations, particularly the need for eight-hourly dosing of gabapentin in dogs, it is worth confirming that the current regimen is likely to be achieving adequate plasma levels.
Is there a neuropathic component to the pain? Where pain assessment suggests significant central sensitisation or a neuropathic element (which is more common in severe or long-standing arthritis) there is a more coherent rationale for a gabapentinoid as part of a multimodal approach than in straightforward inflammatory osteoarthritis.
Are other treatments being optimised? For osteoarthritis pain in dogs, NSAIDs remain the best-evidenced pharmacological option for most patients. Newer options including monoclonal antibodies such as Librela and targeted interventional treatments may also be worth discussing.
A broader point about evidence in veterinary medicine
The gabapentin situation is not unique. Tramadol, similarly, has been widely used in dogs for chronic pain despite evidence that its bioavailability in dogs is poor and that it is unlikely to achieve meaningful analgesia at typical doses. The pattern of adopting human medicines into veterinary practice based on biological plausibility, and then continuing their use based on clinical habit rather than robust evidence, is a recurring one.
This is not a criticism of individual vets. It reflects the reality that the evidence base for veterinary pain management is significantly less developed than for human medicine, and that vets are doing their best within those constraints. It is, however, a reason to consider specialist pain assessment for dogs with complex or inadequately controlled pain, rather than assuming that the current regimen is optimal.
If your dog is on gabapentin or pregabalin
Do not stop any medication without speaking to your vet first. If you have questions about whether your dog’s pain management could be improved, or would like an independent specialist review, a pain assessment can provide a structured and evidence-based evaluation.
References
Bell, A., Helm, J. & Reid, J. Veterinarians’ attitudes to chronic pain in dogs. Veterinary Record 175, 428–428 (2014).
Giudice, E. et al. Clinical findings in degenerative lumbosacral stenosis in ten dogs—A pilot study on the analgesic activity of tramadol and gabapentin. J Vet Behav 33, 7–15 (2019).
Miles J., et al., Tramadol and gabapentin improve peak vertical force in osteoarthritic dogs already receiving non-steroidal anti-inflammatory drugs BSAVA Congress abstract 2020.
Petchnamthong, S., Krambunlue, T. & Suwanna, N. Macleaya Extract versus Pregabalin Therapeutic Effectiveness for Neuropathic Pain in Dogs. Vet. Med. Int. 2024, 9939754 (2024).
Plessas, I. N., Volk, H. A., Rusbridge, C., Vanhaesebrouck, A. E. & Jeffery, N. D. Comparison of gabapentin versus topiramate on clinically affected dogs with Chiari-like malformation and syringomyelia. Veterinary Record 177, 288–288 (2015).
Radulovic, L. L. et al. Disposition of gabapentin (neurontin) in mice, rats, dogs, and monkeys. Drug Metab. Dispos. 23, 441–448 (1995).
Reader, R., Olaitan, O. & McCobb, E. Evaluation of prescribing practices for gabapentin as an analgesic among veterinary professionals. Vet Anaesth Analg (2021) doi:10.1016/j.vaa.2021.06.007.
Thoefner, M. S., Skovgaard, L. T., McEvoy, F. J., Berendt, M. & Bjerrum, O. J. Pregabalin alleviates clinical signs of syringomyelia-related central neuropathic pain in Cavalier King Charles Spaniel dogs: a randomized controlled trial. Vet Anaesth Analg 47, 238–248 (2020).
