The blood–brain barrier (BBB) is a critical protective system that regulates the movement of molecules between the bloodstream and the brain. Dysfunction of the BBB has been linked to cognitive decline in both human neurodegenerative conditions and the normal aging process. In this study, Merbl and colleagues (2025) assessed whether MRI subtraction enhancement analysis (SEA) could be used to detect and quantify BBB dysfunction in dogs with canine cognitive dysfunction (CCD).
The research involved MRI scans of 13 dogs with CCD (10 from the Koret Veterinary Teaching Hospital and 3 from Washington State University) compared to 15 control dogs. Using SEA, the team measured “positive-permeable” voxels and generated a BBB dysfunction score (BBBD) for each subject.
The results showed that mean BBBD scores did not differ significantly between CCD and control groups. While some CCD dogs exhibited evidence of BBB dysfunction, it was not consistent across all cases. Interestingly, SEA has proven more effective in detecting BBB breakdown in dogs with other conditions such as neoplasia or seizures, suggesting that either CCD-related BBB dysfunction occurs only in a subset of affected dogs or that SEA may not be sensitive enough for this application.
These findings highlight the complexity of detecting BBB dysfunction in dementia-like conditions in dogs. The study suggests that alternative imaging or molecular methods may be required to better understand how the BBB contributes to canine and human cognitive decline.
Source: Merbl, Y., Mondrus, E., Hanael, E., & Shamir, M. H. (2025). Blood–brain barrier permeability changes in dogs with suspected canine cognitive dysfunction using magnetic resonance imaging subtraction enhancement analysis. Frontiers in Veterinary Science, 12, published May 13, 2025.
