Canine meningitis and meningoencephalitis in eastern Australia

Area of Science:

• Veterinary Neurology
• Immunology
• Infectious Diseases

Background:

• Meningoencephalitis presents diverse neurological signs in dogs, stemming from infectious and non-infectious origins.
• Steroid-responsive meningitis arteritis (SRMA), meningoencephalomyelitis of unknown origin (MUO), and eosinophilic meningoencephalomyelitis (EM) are key differentials.

Purpose of the Study:

• To retrospectively evaluate and compare clinical findings, diagnostic results, treatments, and outcomes for dogs diagnosed with SRMA, MUO, and EM on Australia's east coast.

Main Methods:

• Retrospective analysis of 89 dogs diagnosed with SRMA, MUO, or EM.
• Data included signalment, clinical signs, MRI/CT findings, laboratory results (CRP, CBC, CSF), and treatment protocols.
• Patient outcomes, treatment duration, and relapse rates were assessed.

Main Results:

• Cervical pain was prevalent in EM and SRMA (100%) and 50% of MUO cases.
• SRMA dogs had higher serum CRP levels (P<0.01) and were less prone to paresis (vs. EM) or ataxia (vs. MUO).
• Eosinophilic pleocytosis indicated CNS infections (angiostrongyliasis, cryptococcus) in 12 dogs.

Conclusions:

• Eosinophilic meningoencephalomyelitis (EM) cases demonstrated the most favorable prognosis, characterized by shorter treatment durations and longer survival times.
• While varied treatments were employed, immunosuppressive medications formed the cornerstone of therapy.
• Distinguishing between SRMA, MUO, and EM is crucial for predicting patient outcomes in canine meningoencephalitis.