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One common recommendation for conditions like acute non-compressive nucleus pulposus extrusion (ANNPE), fibrocartilaginous embolism (FCE), and hydrated nucleus pulposus extrusion (HNPE) has been strict exercise restriction—think cage rest for 4-6 weeks—to prevent relapse or worsening. But what if that long-held practice isn't as critical as we thought? A recent retrospective study from the Queen's Veterinary School Hospital at the University of Cambridge challenges this norm, suggesting that allowing exercise post-diagnosis doesn't lead to poorer outcomes in the short term. Let's check out the details and explore what this means for our rehab protocols.

The Study at a Glance

Published in the Journal of Veterinary Internal Medicine in 2025, Phillips and Freeman analyzed 40 dogs diagnosed with ANNPE, FCE, or HNPE via MRI. These conditions typically present with sudden, often non-painful myelopathic signs, like paresis or plegia, following vigorous activity or trauma. The standard approach? Conservative management with rest to avoid further nucleus pulposus (NP) extrusion through a ruptured annulus fibrosus (AF).

The study's hypotheses were straightforward:

1.     Allowing exercise after diagnosis doesn't reduce recovery chances or increase short-term relapse risk (within 4 weeks post-discharge).

2.     No difference in outcomes between rested and exercised groups.

Methods and Grouping

This was a retrospective review of cases from 2012-2023. Dogs were included if they had acute onset myelopathy, MRI confirmation, and at least 4 weeks of follow-up. Exclusions covered concurrent conditions, incomplete records, or surgical interventions.

•     Rest Group (n=18): Owners were explicitly instructed to enforce rest (e.g., cage/crate confinement or restricted exercise).

•     Exercise Group (n=22): No specific rest instructions—dogs could resume normal activity.

Neurological grading used a modified Frankel scale (0=normal to 5=plegic with no deep pain). Follow-up involved re-evaluations, vet records, or owner phone calls to check for improvement, relapse, or full recovery.

Key Results

•     No Relapses or Deterioration: Across both groups, zero dogs relapsed or worsened in the 4-week window post-discharge.

•     Similar Outcomes: No significant differences in recovery rates. About two-thirds improved by at least two grades, and 47% fully recovered (grade 0).

•     Diagnostics Breakdown: ANNPE was most common (22 cases), followed by FCE (11) and HNPE (7). The rest group had more HNPE cases, while exercise had more FCE—something to note for interpretation.

•     Other Insights: Triggering events (e.g., jumping) were reported in 38%, lateralization in 61%, and spinal pain in 35%. Hospital stays averaged 4.2 days, with 7.5% not surviving to discharge due to progressive myelomalacia.

Statistically, presentation grades were comparable between groups (p=0.5), ruling out bias there.

What Does This Mean for Canine Rehab?

This study flips the script on mandatory strict rest. Traditionally, we've advised cage confinement to minimize spinal movement and prevent further NP extrusion, drawing from concerns in compressive disc diseases. But for these non-compressive or minimally compressive conditions, the extruded NP is often non-degenerate and liquid-like, potentially reducing the risk of additional contusive injury once the initial event occurs.

Practical Implications

•     Earlier Integration of Rehab: If exercise doesn't heighten relapse risk, we could start gentle, controlled activities sooner—think hydrotherapy, passive range of motion, or low-impact exercises tailored to the dog's grade. This might accelerate recovery, especially since a prior study (Gouveia et al., 2022) showed benefits from early neurorehab in ANNPE cases.

•     Owner Compliance and Welfare: Strict rest is tough on dogs (boredom, muscle atrophy) and owners (logistics, guilt). Easing restrictions could improve adherence and quality of life, particularly for active breeds like Staffordshire Bull Terriers or Labradors, which dominated this cohort.

•     Diagnosis-Specific Caution: Results are strongest for ANNPE and FCE. With fewer HNPE cases in the exercise group (and potential mild compression in HNPE), the same recommendations could not be ‘officially’ made. 

•     Incontinence Management: 15% had urinary issues at discharge, with mixed resolutions. Rehab professionals should prioritize bladder expression techniques and monitoring in protocols.

Limitations to Keep in Mind

Retrospective studies aren't perfect—small sample size (40 dogs), no standardized exercise protocols, and reliance on owner-reported compliance. Diagnoses lacked histopathology, and follow-up was sometimes phone-based rather than clinical. Plus, longer hospital stays might have given "exercise" dogs inadvertent rest. A prospective, randomized trial would strengthen these findings.

Final Thoughts: Time to Evolve Our Approach?

This research supports a more flexible mindset: for stable ANNPE/FCE/HNPE cases, immediate exercise might not be a bad thing. As rehab specialists, let's use this to advocate for individualized plans—balancing rest with early mobility to optimize outcomes. Of course, we need to always monitor closely in those first 4 weeks to spot a relapse.

Have you shifted away from strict rest? I hope so!

I was ahead of the curve!  For proof, check out these previous blogs:

May 20, 2018  IVDD Back Pain & the Crate Rest Fairy!

https://www.fourleg.com/Blog?b=354  

Nov 13, 2021  Conservative Management  of IVDE

https://www.fourleg.com/Blog?b=539  

Dec 30, 2023  Conservative Management of IVDH and Disc Resorption or Regression

https://www.fourleg.com/Blog?b=651  

So, until next time, Cheers!

Laurie

Reference: Phillips K, Freeman P. Exercise Restriction Does Not Change Outcome in Dogs After Diagnosis of Acute Non-Compressive Nucleus Pulposus Extrusion, Fibrocartilaginous Embolism, or Hydrated Nucleus Pulposus Extrusion. J Vet Intern Med. 2025.