• Cognitive dysfunction is an age-related neurodegenerative disease that impairs memory and learning.
• Clinical signs and immuno-histopathological findings of CDS resemble forms of dementia seen in Alzheimer patients (Dementia Alzheimers Type (DAT)).
• CDS can manifest itself in multiple unspecific clinical signs that increase in quantity and severity over time in affected cats. Print off the owner factsheet on Cognitive dysfunction Cognitive dysfunction syndrome to give to your client.

Presenting signs

• Summary: changes in cell function and neurotransmission in the brain of the CDS patients lead to malfunctions of short term memory, loss of learned behavior, impairment of the processing of sensory information, reduction in cognitive capacity, and alterations of mood. Taken together these create typical patterns of signs that owners recognize.
• Progression: the progress of CDS is related to the general rate of aging in the feline. Quite significant changes can occur in the space of weeks or months. Worsening of the condition may be precipitated by stressful events such as hospitalization, kenneling, surgery or a house move. Ideally, cats should be behaviorally assessed before these events.
• Emotional changes: mild emotional changes may be the first signs of the onset of dementia. Signs include depression (reduction in activity, play and interest in activities the cat formerly enjoyed). A depressed mood is also a common sign of chronic pain and ill health. Increases in anxiety and fear leading to irritability and aggressiveness.
• Defects of short-term memory: the cat repeatedly performs certain actions such as asking for attention, food and other rewards. These behaviors may also be learned as a result of owner reinforcement. Malfunction of short-term memory is at the root of many of the problems seen in CDS.
• Disorientation: the cat has trouble recognizing people, locations, or objects. This may lead to secondary problems, such as house soiling and trouble to find locations in the home, eg door to outside, cat flap, water and food dish.
• Changes in sleep-wake cycle: the cat tends to sleep mostly during the day and appears restless at night, often waking up and crying out loudly. Pain and illness are also significant factors in night time restlessness in cats, eg chronic arthritic pain may make rest uncomfortable, and deafness can result in the cry becoming loader than previously.
• Loss of learned behaviors: failure to respond to commands and social signals that inhibit unwanted behavior. This contributes to loss of social inhibition and alterations in relationships with people and other animals in the home.
• Loss of house training  Indoor toileting (example of a learned behavior): a previously house trained cat will suddenly urinate and/or defecate inside the house and/or outside its litter box. This clinical sign can be caused by numerous medical and behavioral problems that have to be ruled out, especially osteoarthritis, hyperthyroidism and hypertension. Once the underlying cause of CDS has been treated the cat may need to be re-housetrained from scratch.
• Changes in interaction with the environment: reduced greeting of the owner, familiar persons or pets, decreased response to commands. A depressed mood and lack of interaction tends to isolate cats from their owners, who may not instigate play or give attention. Through a loss of stimulation and reward of normal activity the degradation of the human-animal bond leads to social isolation that contributes to worsening signs of CDS.
• Neurological Neurological examination: in the latter stages of CDS, neurological impairment may be seen. These include ataxia, apparent sensory loss (loss of vision/hearing) and changes in locomotor reflexes. Cats can occasionally progress to this stage quite rapidly (within a few weeks). Any neurological signs must be investigated thoroughly as there are numerous other potential medical causes.

Age predisposition

• The onset of clinical signs is seen in older cats, with as many as 28% of pet cats aged 11-14 years developing at least one geriatric-onset behavior problem.
• This increases to over 50% for cats of 15 years of age or older.

Breed/Species predisposition

• All breeds are equally affected.