What is Steroid Responsive Meningitis?
Steroid Responsive Meningitis (SRMA) is an autoimmune condition which affects dogs and is characterised by inflammation of the blood vessels lining the nervous system.
It typically affects 6 to 18 month olds and is often acute.
Although any breed can get SRMA, it is most common in Bernese mountain dogs, Weimaraners, Beagles and Boxers.
What causes Steroid Responsive Meningitis?
The exact cause of SRMA is not known although studies have looked at various triggers such as demographic, social and environmental factors, as well as other concurrent diseases.
It is most likely to be caused by a mix of genetic and environmental factors.
The condition most often occurs in young puppies when their immune system produces antibodies and an inflammatory response against a harmless protein found in the walls of the blood vessels in the meninges. Meninges are the membrane coverings of the spinal cord and brain.
What are the symptoms?
Dogs with SRMA can exhibit a range of symptoms, including:
- Severe neck pain which may extend to the lower back. This is worst when touching the chin to chest
- Hunched posture
- Lack of appetite
- Swollen and stiff joints
- Stilted walking
- Abnormal heart rhythm in rare cases
- Accumulation of fluid in the lungs and abdomen (effusion) in rare cases
Diagnosis starts by excluding other causes of spinal pain like a joint disease or an infection.
This involves doing blood and urine tests to look for an infection. They are also likely to do x-rays and cerebrospinal fluid for analysis.
An MRI scan is not usually recommended but it could be used to rule out other similar conditions.
CSF sampling and MRI scans are done under general anaesthetic.
SRMA is usually treated by suppressing the immune system with high doses of corticosteroids like prednisolone, which is administered orally or by injection.
They may also be given dexamethasone sodium phosphate which may be administered intravenously in hospital in the first few days – in more severe cases.
Once treatment starts you are likely to notice an improvement in a matter of days. After a few weeks the dose can slowly be reduced over several months.
Corticosteroids often produce side effects such as increased thirst and hunger which manifests as urinating more often and gaining weight.
During treatment they often need to visit the vet to check how their organs are being affected.
They may need to take more medication such as cyclosporine and azathioprine to further suppress the immune system or prevent a relapse.
Early treatment is important for the long-term management of SRMA.
Delayed or inadequate treatment can make the condition become chronic. In such cases they may develop further neurological symptoms, such as paresis (muscular weakness), ataxia (affects coordination and balance) and/or cranial nerve deficits which affect smell, taste and vision.
With prompt treatment they can go on to live a normal life after about six months on medication.
About 20% of dogs will relapse and need further treatment.