Neuroinflammatory diseases of the central nervous system of dogs: A retrospective study of 207 cases (2008-2019).

In this study we describe 207 cases of neuroinflammatory diseases of the central nervous system (CNS) in dogs autopsied at the Athens Veterinary Diagnostic Laboratory (University of Georgia, United States) from 2008 to 2019. Idiopathic and infectious diseases were diagnosed in 111 cases (53.6%) and 96 cases (46.4%), respectively. Idiopathic diseases consisted of granulomatous meningoencephalomyelitis (n = 42; 37.8% of idiopathic cases), nonspecific lymphoplasmacytic meningoencephalomyelitis (n = 39; 35.1%), necrotizing meningoencephalomyelitis (n = 22; 19.8%), presumed steroid-responsive meningitis-arteritis (n = 6; 5.4%), and necrotizing leukoencephalitis (n = 2; 1.8%). Infectious diseases consisted of bacterial infections (n = 49; 51% of infectious cases), viral infections (n = 39; 40.6%), fungal infections (n = 5; 5.2%), and parasitic infections (n = 3; 3.1%). Our study provides an overview of the most frequent neuroinflammatory diseases of the CNS of dogs in our diagnostic routine; indicates that a comprehensive diagnostic approach, including a thorough evaluation of the pathology findings and ancillary laboratory testing results, is important for an adequate diagnosis of neurologic diseases in dogs; and underscores the problems associated with the variability in tissue sample collection methods among cases. The great number of nonspecific lymphoplasmacytic meningoencephalitis also highlights the need for development of molecular laboratory tests to identify potential infectious agents in these cases.