Domestic Dementia
Animals that live long enough to develop tooth decay or gray hair are rare in the natural world. Functionally, it is unknown whether there are any animals that can develop Alzheimer's and its analogues. Animals who already have worn-down teeth and hip issues are unable to continue living in nature when they have significantly lost their memory and instinct.
In order to find animals that live long enough to have this ailment, which is prevalent and thoroughly studied in dogs, you must seek to pets. This condition is officially known as canine cognitive impairment (CCD). Changes in sleep habits, strange routes taken when strolling around the house, incontinence, anger, and a lack of interest in family members are all warning signals.
Thankfully, CCD can be effectively treated to some extent. One such approach is providing them with foods high in fatty acids and antioxidants rather than just plain kernels. For another, exposing them to novel surroundings, allowing them to interact with others, and receiving other types of stimulation will maintain their cognitive function. It appears that teaching an aging dog new tricks is not only possible but also neurologically sound.