Steroid-Responsive Meningitis-Arteritis (SRMA)

Clinical signs

Steroid-responsive meningitis-arteritis generally affects young dogs that are less than 2 years of age; rarely, older dogs are affected. Any breed of dog can be affected, however, some breeds are predisposed, including beagles, golden retrievers, boxers, Bernese Mountain dogs and German shorthaired pointers. Steroid-responsive meningitis-arteritis is the most common cause of an elevated temperature and spinal pain in young dogs in the UK. Most often, affected dogs will have low head carriage, a stiff neck, and neck pain. Back pain is also possible. Some dogs will appear stiff while walking and have swollen joints.

Diagnosis

There is not a specific test for steroid-responsive meningitis-arteritis. Diagnostic tests are performed to rule out other causes of neck and back pain, and generally include blood tests, imaging of the neck and/or back (e.g. an MRI scan) and collection of the cerebrospinal fluid (CSF) under general anaesthesia. Often additional tests are undertaken to rule out an infection. A presumptive diagnosis of SRMA is made after ruling out other causes of neck and back pain, and by demonstrating the presence of inflammation and neutrophils (a specific type of inflammatory cell) in the CSF.

Treatment

Treatment of SRMA involves the administration of medication, most commonly a corticosteroid (i.e. prednisolone) to suppress the immune system. The duration of treatment is variable; in most cases, the dose of prednisolone is slowly reduced over several months. It is possible for relapses of the clinical signs to occur, resulting in longer treatment courses. In some cases an additional medication may be administered alongside prednisolone to aid immune system suppression and to enable tapering of the prednisolone. Common side effects of prednisolone may include depression or lethargy, increased appetite, increased thirst and urination, panting, hair thinning, muscle wastage, and an increased risk of infection.

Prognosis

The prognosis for dogs with SRMA is considered to be fair to good. Clinical signs generally start to improve within a few days of starting treatment. In many cases treatment can be stopped after several months and dogs go on to have a good quality of life. Relapses of the condition are possible however, reported to occur in up to 60% of dogs. Most dogs suffering from a relapse of SRMA demonstrate similar clinical signs to the original onset of the condition. A relapse of SRMA can
generally be treated successfully using the same or similar medications. Sadly, the mortality rate of SRMA is approximately 5-8%.

Follow-up

While undergoing treatment, frequent follow-up appointments are required to monitor for the recurrence of clinical signs and to modify the medication dosage. Blood tests may also be recommended to measure inflammatory markers and to assess the function of the organs (e.g. liver) which may be affected by treatment. The frequency of these recheck appointments will be dependent on the dog’s response to treatment.

If you are concerned about the health of your pet you should contact your veterinary surgeon.