Dog study links rapamycin to reduced brain inflammation in dementia cases

A pilot study examined the effects of rapamycin on 12 dogs diagnosed with dementia. One group received the drug; the others received a placebo. After the dogs died, researchers counted microglial cells, which produce inflammation linked to dementia.

Julie Moreno, a molecular biologist at Colorado State University, conducted the analysis. She reported fewer microglial cells in the brains of dogs that had taken rapamycin. Ralph's brain showed a similar reduction compared with a placebo-treated dog.

Ralph's participation The Rowe family adopted Ralph in 2012.

In 2024 the dog began showing signs of confusion and anxiety. A February 2025 cognitive test led to a clinical diagnosis of dementia, after which Ralph joined the Dog Aging Project. Comparative psychologist Evan MacLean administered a short-term memory test in which Ralph repeatedly failed to locate a hidden treat.

MRI scans performed by McGrath later showed enlarged fluid-filled spaces consistent with brain shrinkage.

Post-mortem findings Ralph died in December.

His brain was examined alongside tissue from the other study dogs. Moreno presented images indicating lower microglial density in Ralph's sample than in the placebo case. Both species show neuron loss and cavity enlargement as the disease progresses.

The Rowe family stated that Ralph's contribution provides them comfort. They said his participation may help future research on dementia treatments for dogs and humans.