Pregabalin linked to slower MRI anaesthetic recovery in horses
Bottom line
Pregabalin given before general anaesthesia appears to lengthen recovery time in horses undergoing elective MRI, according to a retrospective Equine Veterinary Journal study of 128 cases. Investigators compared 52 horses that received oral pregabalin with 76 controls and found that pregabalin was associated with a significantly longer time to standing — 60 minutes versus 53 minutes — but not with worse overall recovery quality scores. The authors also identified other contributors to longer recovery, including older age, acepromazine use, xylazine given during recovery, longer time to first movement, and longer time to extubation. (pmc.ncbi.nlm.nih.gov)
Why it matters: For equine veterinary teams, the finding is less about a dramatic safety signal than about planning. Recovery is the highest-risk phase of equine anaesthesia, and even modest delays can affect staffing, stall use, monitoring intensity, and decisions around pre-anaesthetic medication in horses scheduled for MRI. The study adds to a growing body of MRI-focused recovery research: a recent retrospective study found pre-anaesthetic trazodone did not significantly change recovery time or scores in horses undergoing orthopedic MRI, suggesting sedative and analgesic choices may not affect recovery in the same way. (pmc.ncbi.nlm.nih.gov)
What to watch: Prospective studies will be needed to confirm whether pregabalin itself is driving the longer recoveries and whether protocol changes can preserve analgesic benefit without extending time to standing. (pmc.ncbi.nlm.nih.gov)
A new equine anaesthesia study suggests oral pregabalin may slow recovery after isoflurane anaesthesia in horses undergoing elective MRI, even if it doesn’t appear to worsen the quality of that recovery. In the retrospective cohort, published in Equine Veterinary Journal, horses that received pregabalin before anaesthesia took longer to stand than matched controls, with a median recovery time of 60 minutes versus 53 minutes. Recovery quality scores, however, were not significantly different between groups. (pmc.ncbi.nlm.nih.gov)
That distinction matters because recovery remains the most dangerous part of general anaesthesia in horses. Reviews of the literature and more recent retrospective analyses continue to describe the recovery phase as the period of greatest risk, with complications such as fractures, myopathy, and neuropathy carrying outsized consequences even in elective cases. MRI cases are especially relevant because they often involve otherwise stable horses anesthetized for diagnostic imaging rather than surgery, making medication effects on recovery easier to scrutinize. (pmc.ncbi.nlm.nih.gov)
In the new study, investigators evaluated 128 horses undergoing elective MRI of the appendicular skeleton, including 52 treated with pregabalin and 76 controls. Based on the study summary and available full-text details, pregabalin administration was associated with a statistically significant increase in time to standing, while overall recovery scores were unchanged. The authors’ model also linked longer recovery to increasing age, acepromazine administration, xylazine use during recovery, delayed first movement, and delayed extubation. In practical terms, the study points to pregabalin as one contributor within a broader recovery profile rather than a standalone explanation for every slow recovery. (pmc.ncbi.nlm.nih.gov)
There doesn’t appear to be a press release or broad industry response tied to the paper, but the result lands in a clinically active area. Recent equine MRI recovery research has focused on how commonly used behavior-modifying or analgesic drugs shape the post-anaesthetic period. One 2025 retrospective study from North Carolina State University reported that pre-anaesthetic trazodone did not significantly affect recovery scores, recovery duration, or sedative use in horses undergoing orthopedic MRI, underscoring that different pre-anaesthetic drugs may carry different recovery tradeoffs. (mdpi.com)
Why it matters: For veterinary professionals, this is a workflow and case-selection story as much as a pharmacology story. A seven-minute increase in median time to standing may sound modest, but in equine recovery, extra time on the ground can mean prolonged supervision, more recovery sedation decisions, delayed turnover of MRI and recovery facilities, and potentially more concern in horses already carrying risk factors for neuropathy or myopathy. The absence of a drop in recovery quality is reassuring, but it doesn’t fully neutralize the operational impact of a slower recovery in a species where the recovery window is already high stakes. (pmc.ncbi.nlm.nih.gov)
The study also raises a broader question about balancing pre-emptive analgesia against recovery efficiency. Pregabalin may still offer value in multimodal pain management, but this paper suggests teams should weigh that potential benefit against a measurable delay in standing recovery for MRI cases under isoflurane. Because the study was retrospective, it can show association, not causation, and unmeasured confounding is still possible. Even so, the findings are actionable enough to inform pre-anaesthetic discussions among anesthesiologists, internists, surgeons, and referring veterinarians. (pmc.ncbi.nlm.nih.gov)
What to watch: The next step is prospective, protocol-standardized work that can test pregabalin dose, timing, case selection, and interaction with other recovery drugs to determine whether the recovery delay is consistent, clinically meaningful across settings, and avoidable without giving up analgesic goals. (pmc.ncbi.nlm.nih.gov)