Natalie Stilwell, DVM, MS, PhD
Cognitive impairment in cats is tricky—there’s just not much information on the topic for veterinary teams. At the 2018 American Association of Feline Practitioners conference, held in Charlotte, North Carolina, Margaret Gruen, DVM, MVPH, PhD, provided clarity on the complex etiology of feline cognitive dysfunction syndrome (fCDS). She also offered tips for veterinarians on diagnosis and management.
What is feline cognitive dysfunction syndrome?
Cognitive changes are common in cats aged 10 years and older. However, many of these signs, including decreased activity and social interaction, are subtle and may be mistaken by owners as a normal part of aging. In fact, according to one study, cat owners reported at least one behaviour problem in 28% of cats aged 11 to 14 years and in more than 50% of cats aged 15 and older.1 Many of the reported issues in that study, such as excessive nighttime vocalisation and house soiling, were consistent with fCDS, also called “feline dementia.”
Pathophysiology of fCDS
Although our understanding of cognitive dysfunction in animals frequently is extracted from human medicine, the exact aetiology of neurobehavioural syndromes remains poorly understood. Cognitive dysfunction likely has genetic, nutritional and environmental components.
Dr. Gruen explained that high oxygen demand and lipid content make the brain particularly susceptible to the “cascade of damage” resulting in cognitive dysfunction. Known neuropathologic changes in the brain that lead to cognitive dysfunction include compromised blood flow, chronic inflammation, oxidative damage, and inefficient free radical scavenging. Across species, these processes cause plaques of beta-amyloid protein to surround neurons, ultimately resulting in neuronal dysfunction and death.
Tau protein hyperphosphorylation, another pathologic change, is also documented in humans with Alzheimer disease and in cats, although its role in fCDS remains unknown.