Cognitive Dysfunction Syndrome in Cats

Cognitive dysfunction syndrome (CDS), like Alzheimer’s disease and dementia in humans, occurs in aging cats as their brain and its subsequent functions begin to deteriorate.

Cognitive dysfunction syndrome affects a cat’s memory, their ability to learn, and awareness of their environment, which in turn causes a host of behavioral changes affecting sleep patterns, responses to stimuli, and anxiety levels.

The symptoms of CDS include several behavioral changes that can start to become noticeable as early as 10 years of age. Often, CDS goes undiagnosed as the signs can mimic those of general aging, or other medical conditions, but often become even more pronounced between the ages of 16 to 20 years. Signs of cognitive dysfunction syndrome include:

Spatial Disorientation

• Seems confused or lost in familiar places
• Gets trapped in corners, behind or under furniture, or is unable to move around objects
• Spends long periods staring at walls, at other objects, or off into space
• Gets lost more easily outside
• Aimless wandering

Memory

• Forgets where litter box is, and may eliminate in other areas, including sleeping or eating areas
• Forgets where food or water bowls are, or demands food just after they have eaten
• Doesn’t respond to verbal cues or commands
• Decreased recognition of familiar people or animals
• Difficulty learning new things

Changes in Relationships

• Decreased interest or affection with familiar people or animals
• Disinterested in being petted
• Increased clinginess or dependence on familiar people
• Increased aggression with new or familiar people and animals

Sleep Cycle

• Altered sleep cycles
• Excessive sleeping
• Sleeping more in the daytime
• Abnormal behaviors at night, including restlessness, pacing and vocalization

Changes in Activity

• Reduced activity
• Decreased interest in playing
• Decreased exploratory behaviors
• Decrease or loss of grooming habits
• Decreased appetite
• Decreased response to environment

Anxiety

• Increased anxiousness, restlessness or agitation
• Increased aggression
• Increased vocalization, sometimes with an urgent tone

While the chemistry behind the development of cognitive dysfunction syndrome is continuously being researched, scientists have found some reasons why the brain may experience changes that can lead to this disease. These may include:

• Oxidative stress to neurons- As the brain ages, the antioxidants that normally stop free radicals from damaging neurons begin to fail. The resultant oxidative damage to the neurons can kill them, and greatly reduce the number of neurons, which results in cognitive dysfunction and behavioral changes.
• Loss of Amyloid-beta precursor protein (APP)- This essential protein forms and repairs synapses, the parts of a neuron that pass information from one neuron to another. The reduction of APP may be a factor in age-related reduction of synapses that directly inhibits memory.
• Increase in Aβ plaques- Naturally occurring amyloid beta proteins can begin to misfold onto each other, creating plaques that physically cover the brain’s neurons. This accumulation affects neuron and synapse functions that lead to a loss of brain function, and is the currently accepted reason behind Alzheimer’s disease in humans. 

Since the symptoms of cognitive dysfunction syndrome can be similar to those of other medical issues, your veterinarian will need to know all the unusual behaviors or changes you have noticed in your aging cat. Be sure to tell them of any behavioral, sleep or appetite changes you’ve noticed, when they began, and if they have been increasing as your cat ages.

After a physical exam, your veterinarian may run a series of tests to rule out other medical conditions that could be causing the symptoms, such as arthritis, kidney disease, urinary tract disease, hyperthyroidism, high blood pressure, dental disease, cancer, decreased sight or hearing, or a neurological disorder. Tests can include blood work, urine tests, measuring blood pressure, imaging tests including X-rays, CT scans, MRIs and ultrasounds, oral exams, sight and hearing tests, and neurological functioning tests.

If your cat has been cleared of any other physical conditions, your veterinarian may ask additional questions to determine if there are other behavioral issues going on. CDS can occur in conjunction with other physical or behavioral issues. Once it has been determined that your cat is experiencing cognitive dysfunction syndrome, treatment can be prescribed. 

Since cognitive dysfunction syndrome cannot be cured, treatment aims at making your cat more comfortable by dealing with factors that contribute to their confusion and anxiety, while supporting their cognitive function. Treatments can include adapting the environment, as well as medicinal and nutritional therapies.

Adapting the Environment

• Avoid adding new animals to the household.
• Avoid changing your cat’s food and food placement.
• Make sure food, water and litter boxes are easy to access.
• If mobility is an issue, provide ramps or stairs for easier access to places.
• Add nightlights throughout the house to help your cat see better in the dark.
• If anxious around others, provide a separate, protected space for your cat with food, water and litter for easy access. Confine if necessary.
• If soiling is an issue, provide additional litter boxes in easy to access places, including one on each floor.
• Use a litter box with low sides.

Maintain Schedule

• Promote cognitive function with exercise, new toys and interactive toys.
• Increase your cat’s daytime and evening activity to promote restful sleep at night.
• Maintain the same daily schedule and routine.
• If you leave your cat with a cat sitter, be sure they feed and play with your cat at the same times each day.
• Make any changes gradually.

Medicinal Support

• Selegiline hydrochloride can be given to treat cognitive dysfunction syndrome.
• Anti-anxiety medications can help calm your anxious cat, reducing anxious behaviors such as excessive or nighttime vocalizations.
• Pheromone therapy can help calm your cat naturally, most commonly as a spray or room diffuser placed where your cat spends most of their time.

Supplemental Support

• Antioxidants can reduce oxidative damage to neurons supporting cognitive improvements.
• Omega-3 fatty acids and medium-chain triglycerides (MCTs) can improve cognitive function and reduce Aβ plaque deposits.
• S-adenosyl-L-methionine (SAM-e) reduces free radicals and improves cell function.

Cognitive dysfunction syndrome is a progressive disease without a cure. Treatments and environmental adjustments should be made throughout the rest of your cat’s life to keep them as safe and comfortable as possible. Expect to make adjustments to treatments as your cat ages and symptoms intensify.

Elderly cats should continue to have regular checkups with their veterinarian to address their progressing needs and symptoms of cognitive dysfunction syndrome, as well as to treat any other aging issue they may be experiencing.