Peer-reviewed veterinary case report
Brain Atrophy in Dogs With Meningoencephalitis of Unknown Origin.
- Journal:
- Journal of veterinary internal medicine
- Year:
- 2025
- Authors:
- Gonçalves, Rita et al.
- Affiliation:
- Department of Veterinary Science · United Kingdom
- Species:
- dog
Plain-English summary
This study looked at 23 dogs diagnosed with meningoencephalitis of unknown origin (MUO), a serious brain condition, to see if their brains showed signs of shrinking over time and how that might affect their chances of recovery. The dogs had two MRI scans about a year apart, and the results showed that most of them had changes in their brain structure, with only one dog having a normal scan the second time. Thirteen of the dogs had a relapse of their symptoms, and four sadly passed away during the study. The findings suggested that dogs with more brain volume had a better chance of surviving, while those with new or worsening brain lesions were more likely to relapse. Overall, the study indicates that brain atrophy is likely in these dogs and is linked to poorer outcomes, suggesting that more aggressive treatment may be needed for those showing new lesions.
Abstract
BACKGROUND: Information regarding repeat magnetic resonance imaging (MRI) findings in dogs with meningoencephalitis of unknown origin (MUO) is sparse and it is unknown whether brain atrophy occurs. OBJECTIVES: To determine whether brain atrophy occurs in MUO and evaluate if there is an association between atrophy and survival or relapse. ANIMALS: Twenty-three dogs diagnosed with MUO that underwent MRI of the brain on two occasions at least six months apart. METHODS: Retrospective study. Interthalamic adhesion thickness to brain height ratio (ITr), lateral ventricle to brain height ratio (LVr), interthalamic adhesion thickness/brain height to lateral ventricle/brain height (ITr/LVr), bicaudate ratio (BCR) and total parenchymal brain volume (TPBV) were measured on both MRI studies and compared. RESULTS: Thirteen dogs relapsed and four died during the study period. Median time between MRIs was 12 months, and only one imaging study (1/23) was considered normal on the second scan. All MRI variables measured significantly changed between imaging studies, but only higher TPBV was associated with increased survival (OR = 1.59, CI = 1.006-2.51, p = 0.047); no variables were found to be associated with relapse. New lesions were identified in six dogs (four of which also showed contrast enhancing lesions), with 5/6 of these dogs subsequently relapsing. CONCLUSIONS AND CLINICAL IMPORTANCE: Brain atrophy likely occurs in dogs with MUO and is associated with worse outcomes. Clinical relapse might be likely in dogs with new or contrast-enhancing lesions on repeat MRI, so more aggressive treatment should be considered in these dogs.
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Search related cases →Original publication: https://pubmed.ncbi.nlm.nih.gov/40476772/