Cognitive dysfunction syndrome

Cognitive dysfunction syndrome (CDS) in cats can be compared with Alzheimer’s disease in humans, although the conditions are not identical. Before diagnosing CDS, your vet may want to rule out other medical conditions that can cause similar clinical signs. Medications can help some pets with CDS and nutritional supplements may also help manage the problem.

Elderly cats develop a very similar condition to Alzheimer’s disease or dementia in people. This condition is known as cognitive dysfunction syndrome (CDS).

Researchers are still trying to understand all the changes that occur in the brains of pets with CDS, but studies have determined that deposits of a protein called beta-amyloid play a role. These deposits have an adverse affect on brain functioning.

The exact prevalence of CDS in cats is not well documented, but evidence suggests that the disease becomes more common as pets age.

Some of the subtle clinical signs of CDS can be difficult to distinguish from regular signs of aging. These include things like slowing down and becoming less active. However, cats with CDS also exhibit other signs, including the following:

• House soiling (“forgetting” how to use the litterbox or eliminating outside the box)
• Decreased activity and attention
• Disorientation
• Changes in sleep cycles (pacing or wandering and crying at night)
• Withdrawing from interactions with family members or conversely seeking to be closer or always with a family member

Some pets can seem to not know family members and even exhibit aggressive behavior toward other pets or members of the household, as if they are strangers. Pet owners may also report that a pet has “forgotten” tricks, behaviors, and regular routines that were well established earlier in life.

Your vet will likely begin by reviewing your pet’s medical history. Valuable information can include the duration of the observed abnormalities, the severity of the problem, and whether the problem seems to be getting worse over time.

The most important aspect of diagnosing CDS is to rule out other medical problems that can cause similar clinical signs. For example, an elderly cat that starts soiling outside the litterbox may have another illness such as a bladder infection, diabetes, thyroid disease, or a kidney problem; all of these conditions can cause increased frequency of urination. Similarly, a cat that has arthritis may have difficulty getting into and out of the litterbox and therefore be reluctant to use it. Senior pets can also begin to lose their vision and hearing, which may affect how they interact and respond to family members.

Your veterinarian may recommend a variety of diagnostic tests to rule out other medical issues before making a diagnosis of CDS. Preliminary tests may include the following:

• Blood tests, including a chemistry panel and complete blood cell count (CBC)
• Urinalysis and urine culture testing to evaluate kidney function and look for evidence of kidney or bladder infection
• Radiographs (x-rays) to look for evidence of arthritis and to check for cancer or other changes involving organs in the abdomen or chest
• Abdominal ultrasonography
• Specific blood tests to evaluate thyroid function and look for other medical conditions

There is no cure for CDS but treatment may help improve the signs and slow the progression of the disease. There is currently no licensed medication for cats with the condition.

It has been shown that exercise and mental stimulation can help slow the progression of CDS. Regular exercise that is appropriate for an older pet, combined with environmental enrichment with toys and play activities, may help keep pets more alert as they age.

If the problem becomes too severe and issues such as house soiling, aggression, and poor quality of life become intolerable, euthanasia can be a reasonable option to discuss. Your vet can help you and your family sort out these issues and try to help you make the best decision for you and your pet.