Though many scientific studies use genetically modified mice to replicate what the effects of Alzheimer's disease would be in a human brain, there are several species of animals that naturally develop brain changes that resemble Alzheimer's in humans, namely dogs.
Like people, when dogs age, some develop learning and memory problems, while some remain sharp and as capable of learning as younger dogs. Dogs even have symptoms of cognitive decline that are very similar to those in humans, such as disrupted or irregular sleeping schedules and difficulty recognizing family members and friends.
Elizabeth Head, PH.D, of the Sanders-Brown Center on Aging, said their lab began studying beagles in the early 1990s due to interest in developing a drug to treat "dog dementia", using observations from pet owners about behavioral changes in their older dogs. Not much was known then about cognitive changes in aging dogs (the study group being beagles over eight years old), and the center's research began with finding ways to record and measure these changes.
Read more: What can beagles teach us about Alzheimer’s disease?