The book deeply focuses on the epidemiology, diagnostics, therapy and molecular basis of canine and feline dementia or cognitive dysfunction syndrome. The aim is to provide a broad overview of the current knowledge on canine and feline dementia. Experiences of clinicians are appropriately linked with current scientific knowledge in a readily comprehensible form. In the first three chapters we describe the clinical pictures of canine and feline dementia, discuss the medical causes of the disease and its phenotypic variability. In the 4th chapter we introduce the dog as an appropriate animal model for human Alzheimer’s disease progression. Then we shed light on the neuropathological hallmarks of canine and feline dementia. For the first time we touch upon the modern diagnostic approaches based on the neuroproteomic technological progress. Last but not least, we address the current pharmacological and non-pharmacological approaches for therapy and risk and protective factors of feline and canine dementia. The book addresses clinicians, researchers, university teachers and graduate students in veterinary neurology and medicine.