Nondegenerative Myelopathies & Exercise Restriction in Dogs

In the Literature

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;39(4):e70135. doi:10.1111/jvim.70135

The Research …

Acute noncompressive nucleus pulposus extrusion (ANNPE), fibrocartilaginous embolism (FCE), and hydrated nucleus pulposus extrusion (HNPE) are nondegenerative conditions with acute to peracute onset of myelopathic signs in dogs. Treatment is usually medical, and a period of strict rest has historically been recommended to reduce risk for progression or recurrence of neurologic signs.

This retrospective study evaluated whether an increased chance of relapse was associated with a lack of explicit exercise restriction counseling for pet owners of affected dogs. Forty dogs met the inclusion criteria (ie, presentation with peracute- or acute-onset static or improving myelopathy; MRI confirmation of ANNPE, FCE, or HNPE; minimum 4-week follow-up after discharge). Dogs with owners given specific instructions to provide rest and restrict activity were assigned to the rest group (n = 17); dogs with owners not specifically instructed to provide rest or restrict activity were assigned to the exercise group (n = 23). Neurologic grade did not worsen for any dogs in either group at the time of follow-up, and no disease recurrence was noted.

The study authors concluded that allowing exercise after a confirmed diagnosis of ANNPE, FCE, or HNPE did not predispose patients to a relapse in clinical signs; however, caution is recommended when interpreting these findings for dogs with HNPE, as there were few cases of HNPE in the exercise group and fewer in the rest group.

… The Takeaways

Key pearls to put into practice:

• ANNPE, FCE, and HNPE differ from Hansen type I intervertebral disc disease (IVDD) in that these diseases are noncompressive and/or nondegenerative myelopathies that occur mostly in nonchondrodystrophic dogs, and type I IVDD involves herniation of degenerative disk material that typically causes compression of the spinal cord, most commonly in chondrodystrophic dogs.^1,2

• A tear in the annulus fibrosus is present in conditions of disk extrusion, and rest may be recommended to decrease recurrence risk until healing has occurred.³ Disk material is nondegenerate and hydrated (ie, liquid) in cases of ANNPE and HNPE and degenerate and mineralized in cases of type I IVDD.¹ ANNPE and HNPE are typically nonprogressive and have a low recurrence risk compared with type I IVDD, which has a high risk for recurrence^2,3; therefore, rest is still recommended for patients with IVDD but may not be indicated for patients with nondegenerative myelopathies.

• MRI is the preferred imaging for these conditions and should be used for diagnosis.^3,4 If MRI cannot be performed and a presumptive diagnosis must be made, ANNPE, FCE, and HNPE can be suspected in dogs that are nonchondrodystrophic and have a nonprogressive myelopathy.

• Studies evaluating activity recommendations on outcomes in dogs with myelopathies are lacking. Future studies should evaluate large patient populations, compare a uniform disease process, and be prospective in nature so specific activity protocols can be developed to guide owners of dogs with these conditions.