Heterogenous deposition of β-amyloid in the brain of aged dogs

Dogs have been used as animal models for human diseases in which there is beta-amyloid (A beta) deposition in the central nervous system (CNS), such as Alzheimer's and cerebral amyloid angiopathy (CAA). However, many aspects of A beta deposition in the CNS of dogs still remain unknown. This study aimed to evaluate the deposition of A beta in different areas of the CNS of aged dogs from different breeds. A beta was detected in the brains of aged dogs, forming either senile plaques in the neuropil of cortical gray matter or within the walls of parenchymal or leptomeningeal blood vessels. There was a positive correlation between aging and senile plaques or CAA. In dogs older than 8 years, there was no correlation between the area of A beta plaques and age, with frontal, temporal, and occipital cortices being affected with approximately equal frequency. There was a positive correlation between A beta deposition in vessel walls and age. Importantly, CAA was associated with the occurrence of microperivascular hemorrhages in the brains of aged dogs. In conclusion, this study demonstrated that A beta deposition as plaques or within vessel walls are extremely heterogenous in dogs from different breeds and sizes. Although many features of this disease in dogs are similar to those observed in humans, the choice of dog breed and size as a model for human disease will substantially affect the pattern of A beta deposition. (C) 2020 Elsevier Inc. All rights reserved.

Automated summary

The study found that Aβ deposition in the brains of aged dogs is positively correlated with age and is associated with senile plaques or CAA. There is no correlation between the area of Aβ plaques and age in dogs older than 8 years, but Aβ deposition in vessel walls is positively correlated with age. Aβ deposition as plaques or within vessel walls varies greatly among dogs of different breeds and sizes.