Steroid Responsive Meningitis In Dogs
What is steroid responsive meningitis in dogs?
Steroid responsive meningitis (SRMA) is an autoimmune condition in dogs where the blood vessels that line the meninges, layers of the membrane that cover the spinal cord and brain – a vital part of the nervous system, become inflamed. There is no known cause.
It can affect any breed, but steroid responsive meningitis in dogs is most often found in Boxers, Weimaraners, Bernese Mountain Dogs and Beagles, particularly between six and 18 months old.
This condition is rare in the UK, but when it does occur, it’s often acute.
What causes steroid responsive meningitis?
Steroid responsive meningitis has no known cause, though it is most likely to develop as a result of environmental and genetic factors rather than any specific diseases.
It occurs when a dog’s immune system attacks a protein in the walls of the blood vessels within the meninges. This protein is harmless and is normally found within the dog’s body, so the resulting antibodies and inflammation are due to an autoimmune response.
Is steroid responsive meningitis in dogs contagious?
The condition is not caused by an infection, and it is not contagious, so your dog can’t pass it on to other pets or people.
Steroid responsive meningitis dogs symptoms
There are a number of symptoms associated with steroid responsive meningitis, with the most common being a fever and severe neck pain that often extends into the lower back. The pain will be most severe when your dog tries to touch its chin to its chest.
There are no other neurological issues associated with SRMA, but your pet may:
- Be hunched over
- Be lethargic
- Eat very little, or not at all
- Suffer with stiff, swollen joints as a result of the inflammation
- Have difficulty or stiffness when walking, or display unusual walking patterns
- Be reluctant or unable to exercise
Your dog’s heart may also fall into an abnormal rhythm as a result of inflammation of the pericardium, which is the sac that covers the heart. They also may suffer from effusion, which is where fluid collects in the abdomen and lungs, though both of these issues are rare.
How is it diagnosed?
It’s important that your pet is diagnosed and treated quickly, so your veterinary neurology specialists will work to uncover any other causes that could be contributing to your pet’s symptoms. This includes diseases such as:
- Bone infections
- Joint disease stemming from your pet’s immune response
- Soft tissue infections
Firstly, they will rule out infections or joint disease that can cause spinal pain. As part of this, they will undertake tests, including
- Blood tests
- Urine tests
- CSF (cerebrospinal fluid) taken from the neck or lower back
If necessary, your dog may also undergo veterinary diagnostic imaging, such as an MRI. However, this isn’t a usual procedure for steroid responsive meningitis, because it is used to rule out any other causes.
In order to confirm a diagnosis of steroid responsive meningitis in dogs, your vet will need to uncover inflammation and evidence of a particular inflammatory cell while examining your pet.
Steroid responsive meningitis treatment
As steroid responsive meningitis in dogs is an autoimmune condition, treatment usually involves flooding the immune system with high doses of prednisolone or other steroid and anti-inflammatory medication, which is either given via injection or orally. This usually continues for between five and seven months.
Where the condition is more severe, your dog may need to stay in hospital for a few days. While here, they may be given dexamethasone sodium phosphate, another anti-inflammatory treatment, intravenously.
It might also be necessary for your pet to take other oral medication, such as azathioprine or cyclosporine, which work to suppress the immune system further and can help prevent the condition returning when used in conjunction with a reduction in the dose of steroids. You should be able to give these to your pet at home.
Where your pet has been given steroids, they will start to improve within a few days, with their symptoms becoming less apparent or even disappearing completely. After a few weeks, their dosage can slowly start to be reduced until the autoimmune response has abated, which will take a few months.
It’s important that you make and keep appointments with your vet during this time, as they will need to check on your pet’s progress and see whether the treatment is having any affect on their organs.
Blood tests may be carried out to assess this, though this will depend on how your pet is responding to its treatment. Visits to your veterinary neurologist might also be needed during treatment, so that they can assess your pet’s progress.
While improvement can be rapid, there are some side effects to steroids, which include:
- Increased hunger and thirst, resulting in weight gain and more frequent urination
- Increased risk of respiratory and urinary infections, among other infections
Your vet will talk through any likely side effects, and will be able to advise you further on what to do should your pet experience any.
Steroid responsive meningitis in dogs prognosis
Though the prognosis is usually good, in order to effectively manage steroid responsive meningitis, it’s essential that your pet receives treatment as soon as possible. If you delay, or if the treatment isn’t suitable, the condition may become chronically ill, and your dog may develop additional symptoms, including:
- Paresis – muscle weakness
- Ataxia – degeneration of the nervous system that affects coordination and balance
- Cranial nerve defects – affecting vision, taste and smell
The sooner your pet is treated, the sooner they can go on to live a normal life, although they will be on medication for around six months.
However, around 20% of dogs can have a steroid responsive meningitis relapse, both during treatment or afterwards, so if your dog does fall into this category, they will need additional treatment. It’s therefore vital that you continue with veterinary appointments and monitor your pet for symptoms.
How long is recovery?
Most dogs start to make improvements after just two or three days, and many go into remission in two weeks.
After a few weeks, their steroid doses can start to be reduced, and this reduction can continue over the following five to seven months. Providing your dog doesn’t have a relapse during this time, their treatment can stop and they can resume a normal life with no lasting effects.