CONDITION
Steroid-Responsive Meningitis-Arteritis (SRMA)
Steroid-responsive meningitis-arteritis is an inflammatory condition in which the body's immune system targets the membranes surrounding the brain and spinal cord, and the blood vessels that supply them. It occurs most often in young dogs, usually between 6 months and 2 years of age, and certain breeds, including Beagles, Boxers, and Bernese Mountain Dogs, are seen more frequently than others. The inflammation tends to develop over hours to days, and can recur in waves even after treatment has begun. Owners often arrive at this page because their dog has developed neck pain that makes them reluctant to lower their head, along with fever and a general sense of being unwell. Some dogs also show stiffness, a hunched posture, or reduced appetite. The signs can look similar to other causes of neck pain or systemic illness, which is why the underlying cause needs to be identified through testing. This page explores what signs may be observed, what is happening in the nervous system and blood vessels, how the condition is investigated through blood tests and analysis of spinal fluid, and what approaches exist to manage the inflammation and reduce the chance of recurrence.
Why this matters now
SRMA most commonly affects young dogs between 6 months and 2 years of age, though it can occasionally occur in older dogs. The acute form often presents suddenly, with dogs appearing severely unwell within a short period.
The acute form typically develops over hours to a few days, with fever, marked neck pain and reluctance to move. Most dogs respond well once immunosuppressive treatment starts, and many recover fully. Where treatment is delayed, insufficient or stopped early, a protracted, relapsing form can develop, and in this form neurological deficits such as weakness, wobbliness or loss of use of the legs can appear. Inflamed vessels around the spinal cord and brain can bleed or become blocked; in recent MRI-based case series this was found in between about one in ten and one in five dogs with SRMA, and some of these dogs developed weakness or paralysis. Relapses were recorded in around a third of dogs in several treatment studies, which is why the response is monitored during and after the taper.
Signals & patterns
Early signals
Neck stiffness and reluctance to move
Affected dogs often hold their head low and resist bending their neck, showing obvious discomfort with movement.
Fever
Dogs frequently develop a high temperature. Feeling warm to the touch is not a reliable guide to fever in dogs; fever is confirmed with a thermometer.
Hunched posture
Dogs may adopt a rigid, arched stance suggesting spinal discomfort.
Lethargy and depression
Affected dogs typically appear dull, reluctant to engage, and less responsive than normal.
Later signals
Severe pain on neck manipulation
Any attempt to move the head or neck may provoke yelping or aggression due to pain.
Difficulty rising
The combination of pain and stiffness can make getting up from lying extremely difficult.
Complete reluctance to eat
Pain may prevent dogs from lowering their head to food bowls.
Neurological signs
Weakness, wobbliness, knuckling of the paws or loss of use of the legs can develop, particularly in the protracted, relapsing form or where inflamed vessels bleed around the spinal cord. These signs indicate spinal cord involvement, and they are also seen in look-alikes that can worsen over hours, such as a disc herniation in the neck.
Click to read about the biological mechanisms
How this is usually investigated
Diagnosis of SRMA typically involves analysis of cerebrospinal fluid alongside blood tests and imaging to rule out other causes of meningitis.
Cerebrospinal fluid analysis
Blood tests
MRI
Infectious disease testing
Options & trade-offs
Treatment centres on immunosuppression to control the aberrant immune response, typically requiring prolonged courses with careful monitoring.
Corticosteroid therapy
High-dose steroids are typically used initially, then gradually tapered, traditionally over around six months, as inflammation resolves. A 2024 trial found similar relapse rates with a six-week course.
Trade-offs: Steroid side effects include increased thirst, urination, appetite, and potential behavioural changes. Premature dose reduction risks relapse.
Additional immunosuppressants
Drugs such as azathioprine or mycophenolate may be used alongside steroids in some cases. Neither is authorised for dogs in the UK; both are human medicines prescribed under the veterinary cascade.
Trade-offs: Additional monitoring requirements and potential side effects. May allow lower steroid doses.
Pain management
Analgesics may be used initially to improve comfort while waiting for immunosuppression to take effect.
Trade-offs: Provides symptomatic relief but does not address the underlying inflammation. Non-steroidal anti-inflammatory drugs given together with corticosteroids increase the risk of stomach and intestinal ulceration, and pain relief given before diagnosis can mask signs.
Monitoring protocols
Regular rechecks, blood C-reactive protein measurement and sometimes repeat CSF analysis may be used to guide treatment duration and identify relapse.
Trade-offs: Involves repeated procedures and costs. C-reactive protein can remain raised after signs have resolved, so it is interpreted alongside the clinical picture.
Common misconceptions
"SRMA is caused by an infection that needs antibiotics."
SRMA is immune-mediated, not infectious. While infection must be ruled out, the treatment is immunosuppression rather than antibiotics.
"Once symptoms resolve, treatment can stop."
Insufficient or prematurely stopped treatment is associated with relapse and with the protracted form of the disease. Protocols taper the dose gradually, traditionally over around six months.
"SRMA always causes permanent neurological damage."
With prompt, appropriate treatment, most dogs recover fully. The condition responds well to immunosuppression in the majority of cases.
Related conditions
Granulomatous Meningoencephalomyelitis (GME)
Granulomatous meningoencephalomyelitis is another inflammatory condition of the central nervous system that can produce similar signs, including neck pain, altered behaviour, and neurological changes, though the pattern of immune cells involved and the typical course differ. Distinguishing between the two often requires analysis of cerebrospinal fluid and sometimes imaging.
Necrotising Meningoencephalitis (NME)
Necrotising meningoencephalitis is also a non-infectious inflammatory disease of the central nervous system, but it destroys brain tissue and mainly affects small breeds such as Pugs, often causing seizures, behaviour change or circling. SRMA centres on the membranes and vessels around the spinal cord and typically causes neck pain and fever rather than seizures, and spinal fluid analysis and MRI help separate the two.
Syringomyelia (CM/SM)
Syringomyelia can produce neck pain and reluctance to lower the head in a way that may resemble the presentation of steroid-responsive meningitis-arteritis, though the underlying cause, disrupted cerebrospinal fluid flow rather than inflammation, is quite different. Imaging of the brain and spinal cord can help clarify which process is at work.
Discospondylitis
Discospondylitis is an infection of the spine that can cause severe neck or back pain, fever, and a hunched posture, overlapping with the signs often seen in steroid-responsive meningitis-arteritis. Blood tests, imaging, and sometimes analysis of spinal fluid are used to distinguish infection from immune-mediated inflammation.
Immune-Mediated Polyarthritis
Immune-mediated polyarthritis can occur alongside steroid-responsive meningitis-arteritis in some dogs, both reflecting misdirected immune activity. When both are present, stiffness and reluctance to move may be more pronounced, and joint fluid analysis can help identify inflammation in the joints as well as the nervous system.
Intervertebral Disc Disease in Dogs
A disc herniation in the neck can cause severe neck pain, a low head carriage and reluctance to move that closely resemble SRMA, although fever is not usually part of the picture. A herniated disc can compress the spinal cord and progress to weakness or loss of use of the legs, and MRI or CT is used to tell the two apart.
The page on this condition is being checked again and is offline for now.
Atlantoaxial Instability
Atlantoaxial instability, seen mainly in young toy-breed dogs, can cause neck pain that resembles SRMA. Movement of the unstable joint can injure the spinal cord and lead to weakness in all four legs, which is one reason imaging is used before the neck is flexed for spinal fluid sampling.
Neck pain with fever in a young dog is not specific to SRMA. Bacterial meningitis (which can be life-threatening), discospondylitis, a disc herniation in the neck and, in small breeds, atlantoaxial instability can look very similar, and these cannot be told apart at home; blood tests, spinal fluid analysis and often imaging are what separate them. A wobbly or weak gait, knuckling of the paws, difficulty standing or loss of use of the legs suggest that the spinal cord itself is affected, and conditions producing these signs can worsen over hours. Painkillers or steroids given before an assessment can mask signs, and several human painkillers are toxic to dogs. Once SRMA has been diagnosed, attention turns to the length of treatment, the side effects of steroids, and recognising a relapse. A return of neck pain, fever or dullness during or after the taper can mark a relapse, and blood C-reactive protein is commonly used alongside the clinical picture to track it.
Last reviewed: 9 October 2026 · Dr Alastair Greenway MRCVS