Infectious meningitis / meningomyelitis
Meningitis (inflammation of the meninges) and meningomyelitis (inflammation of the spinal cord and the meninges) can cause severe spinal pain. Meningomyelitis, by definition, will also cause neurological deficits. Cerebrospinal fluid (CSF) analysis is the most reliable antemortem diagnostic test available for identifying CNS inflammation; it often reveals an increase in the white blood cell number as well as protein elevations. A complete discussion of the diagnosis, treatment and prognosis of infectious CNS disease is presented in site.
Clinical signs: SRMA, also termed necrotizing vasculitis, juvenile polyarteritis syndrome, corticosteroid-responsive meningitis / meningomyelitis, aseptic suppurative meningitis, panarteritis and pain syndrome, is a non-infectious inflammatory condition reported in Beagles, Bernese Mountain Dogs, Boxers and German Short-Haired Pointers (), and urobably occurs in other breeds.
Affected dogs are often young adults (8-18 months : d) but may be of any age, and are usually febrile and hyperaesthetic, with cervical rigidity and anorexia (). Neurological deficits can be seen in the chronic form of this disease. Some dogs (up to 46%) with immune-mediated polyarthritis, especially Bernese Mountain Dogs, Boxers and Akitas, may show similar clinical signs to dogs with SRMA and have concurrent meningitis (). Some dogs may have concurrent glomerulonephritis.
Pathogenesis: An immunological cause of this disease is suspected, resulting in a vasculitis.
Diagnosis: A marked blood neutrophilia with a left shift may be seen at the time of the clinical signs. Cerebrospinal fluid often reveals a marked neutrophilic pleocytosis and protein elevation; cell counts of >100 cells / μJ are common. Neutrophils are non-degenerative, unlike bacterial meningitis. In the majority of dogs with either acute or chronic disease, there are elevations of IgA levels in the CSF and the serum, although this is not specific for this disease.
Treatment recommendations for steroid-responsive meningitis-arteritis.
- 1. Prednisolone 4 mg / kg q24h orally or i.v. for 2 days
- 2. Prednisolone 2 mg / kg q24h orally for 14 days. If clinical signs have improved, a further reduction can be considered
- 3. Prednisolone 1 mg / kg q24h orally for 28 days. If clinical signs are normal, a further reduction can be considered
- 4. Prednisolone 0.5 mg / kg q24h orally for 28 days. If clinical signs are normal, a further reduction can be considered
- 5. Prednisolone 0.5 mg / kg q48h orally for 2 months. If clinical signs are normal, the medication can be stopped
- 6. Azathioprine 2 mg / kg q24h reducing to 1,5 mg / kg every other day orally if clinical signs are refractory to the steroid medication
Treatment andprognosis: The prognosis can be good if dogs are treated early and aggressively with immuno-suppressive doses of corticosteroids (Treatment recommendations for steroid-responsive meningitis-arteritis). Infectious diseases should be ruled out before this treatment is initiated. The treatment is long term, and has been reported to be required for over 2 years in some dogs; however, after this time, serum and CSF IgA levels were still elevated in some dogs (). Monitoring of CSF cell count in dogs with this condition is a sensitive indicator of success of treatment.
Granulomatous meningoencephalomyelitis (GME) is a non-suppurative CNS inflammatory disease of undetermined aetiology in dogs. It is suggested to be a T-cell-mediated delayed-type hypersensitivity (). It is most commonly seen in small-breed dogs, and often in terriers, toy breeds and Poodles, although any breed may be affected ().GME may involve the spinal cord at any level; however, lesions appear to be most severe in the cervical spinal cord (). Findings include apparent cervical pain, rigidity, reluctance to move, hyperaesthesia, cervical paraspinal muscle spasms and neurological deficits. Further information on the pathophysiology, diagnosis and prognosis of this disease is contained in site.
Infection of the CNS may result in an abscess or empyema in subdural or epidural locations. Epidural infections can follow skin disease, vertebral osteomyelitis, discospondylitis or a paraspinal abscess. Clinical signs may include fever, anorexia, lethargy and apparent spinal pain, as well as neurological compromise; however, there may not be a systemic reaction.
Polymyositis / polymyopathies
The main sign of a disease affecting the skeletal muscles is weakness; however, muscle pain (myalgia) may also be a feature, which may present as spinal pain. The weakness accompanying the muscle disease may be discrete, causing an abnormal posture such as neck ventroflexion, especially in cats, leading the clinician to focus on a cervical disease. For a complete discussion of muscle disease, the reader is directed to site.
Arthritis is generally classified as either non-inflammatory or inflammatory (Classification of arthritis). Inflammatory joint diseases can affect multiple joints (polyarthritis) and are either infectious or immune-mediated. Immune-mediated polyarthritides can be further classified as erosive or non-erosive, based on the presence or absence of joint cartilage destruction and typical bone erosion visible on radiographs. Polyarthritis can often present as a spinal pain syndrome, but there is commonly appendicular joint pain present as well. Typically, animals appear to be ‘walking on eggshells’, and are reluctant to lie down or to rise once down. All appendicular joints should be carefully palpated but the absence of a joint effusion does not rule out polyarthritis. The prevalence of spinal pain in dogs with non-infectious non-erosive idiopathic immune-mediated polyarthritis is approximately 30% (). The reader is directed to internal medicine and orthopaedic texts for a more complete discussion on the diagnosis and management of these conditions.
Classification of arthritis
- Degenerative joint disease
- Infectious (septic)
- Immune-mediated (non-septic):
- Canine rheumatoid arthritis
- Feline progressive polyarthritis
- Periosteal proliferative polyarthritis
- Polyarthritis of Greyhound
- Systemic lupus erythematosus
- Polyarteritis nodosa
- Polyarthritis / meningitis
- Lymphocytic-plasmacytic synovitis
- Amyloidosis of Shar-Pei
- • Type I (uncomplicated)
- • Type II (reactive)
- • Type III (enteropathic)
- • Type IV (malignant)