Photo shows an epidural injection.

Degenerative lumbosacral stenosis (DLSS) is a progressive condition in dogs characterised by the narrowing of the spinal canal at the lumbosacral junction. This narrowing compresses nerves, leading to pain and, less commonly, neurological issues.

The condition’s exact causes are not entirely clear, but may involve factors such as congenital abnormalities, past infections, breed predisposition and high-impact physical activities.

DLSS presents primarily as pain, with common symptoms including pelvic limb lameness (in one or both legs) and back pain. Since neurological deficits such as weakness are rare, the condition can be difficult to diagnose accurately. This variability often results in over-diagnosis or under-diagnosis, complicating treatment plans.

Despite these challenges, one certainty is the condition’s progressive nature, requiring long-term management, often through pain relief techniques.

Non-invasive treatment

A common and relatively non-invasive treatment for DLSS is the epidural injection of methylprednisolone acetate, a long-acting corticosteroid.  This injection reduces inflammation around the nerves compressed at the lumbosacral junction. The technique involves delivering the medication into the epidural space, typically between the L7 and S1 vertebrae, where it diffuses around the affected nerves, ligaments and joint capsules.

Epidural injection of pain medications (other than corticosteroids) is carried out daily at Bristol Vet Specialists by the anaesthesia team, and this is a well-known and safe technique that has been used in humans and dogs alike for a long time.

Studies

A couple of studies have explored the effectiveness of long-acting corticosteroid epidural injections: Janssens et al (2009) developed a protocol involving multiple injections at set intervals, finding that 79% of dogs improved, with 53% considered pain free by their owners over a median follow-up period of 46 months.

However, the study excluded cases with severe neurological symptoms or concurrent orthopaedic conditions, which could affect the outcomes.

In contrast, a study by Gomes et al (2020) investigated the impact of a single injection. Their findings showed that 84.4% of dogs improved after just one injection, with a subset of dogs experiencing long-term relief without the need for additional injections.

For dogs that experienced a relapse, surgery was an option, so this approach suggests that for some dogs, a single injection may provide lasting relief.

Conclusion

In conclusion, epidural injections of methylprednisolone acetate can provide an effective and minimally invasive treatment option for DLSS in dogs.

Some dogs benefit from a single injection, while others may require multiple treatments.

It certainly offers an alternative for managing this challenging condition in cases where surgery may not be straight away an option for various reasons.

• A more detailed paper can be found at tinyurl.com/bddmzdsj