Peer-reviewed veterinary case report
Case report: Lympho-histiocytic meningoencephalitis with central nervous system vasculitis of unknown origin in three dogs
- Journal:
- Frontiers in Veterinary Science
- Year:
- 2022
- Authors:
- Isabel Zdora et al.
- Affiliation:
- Department of Pathology, University of Veterinary Medicine Hannover, Hannover, Germany · CH
- Species:
- dog
Plain-English summary
This report discusses three dogs that developed a serious brain condition called meningoencephalitis of unknown origin, which means there was no clear cause found for their illness. These dogs showed sudden and worsening signs of brain problems, like confusion and low energy. Advanced imaging tests revealed significant swelling in their brains, and further examination after death showed inflammation of the brain and blood vessels in the central nervous system. Despite thorough testing, no infectious agents were found that could explain their condition. This case suggests that this type of brain inflammation could be recognized as a new subtype of meningoencephalitis in dogs, but unfortunately, the outcome for these dogs was not positive.
Abstract
Meningoencephalitis of unknown origin (MUO) is an umbrella term for a variety of subtypes of meningoencephalitis of dogs and cats with no identifiable infectious agent. In dogs, granulomatous meningoencephalitis (GME), necrotizing meningoencephalitis (NME), and necrotizing leukoencephalitis (NLE) are the most commonly reported subtypes. However, sporadically there are reports about other subtypes such as greyhound encephalitis or eosinophilic meningoencephalitis. The following case series presents three dogs with peracute to acute progressive signs of encephalopathy. The magnetic resonance imaging (MRI) of two dogs (post mortem n = 1/2) showed severe, diffuse swelling of the cortical gray matter with increased signal intensity in T2weighted (w) and fluid-attenuated inversion recovery (FLAIR) and decreased signal intensity in T1w. Additionally, focal to multifocal areas with signal void in both dogs and caudal transforaminal herniation of the cerebellum in one dog was observed. Post mortem histopathological examination revealed lympho-histiocytic encephalitis and central nervous system (CNS) vasculitis in all dogs. No infectious agents were detectable by histopathology (hematoxylin and eosin stain), periodic acid-Schiff reaction (PAS), Ziehl-Neelsen stain and immunohistochemistry for Canine adenovirus-1, Parvovirus, Listeria monocytogenes, Parainfluenzavirus, Toxoplasma gondii, Herpes-suis virus, Pan-Morbillivirus, Tick born encephalitis virus, Severe acute respiratory syndrome coronavirus (SARS-CoV) 2. Furthermore, two dogs were tested negative for rabies virus. To the best of the authors' knowledge, this is the first report of a lympho-histiocytic encephalitis with CNS vasculitis with no identifiable infectious agent. It is suggested to consider this as an additional subtype of MUO with severe clinical signs.
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Search related cases →Original publication: https://doi.org/10.3389/fvets.2022.944867