What is cognitive dysfunction?
Cognitive Dysfunction Syndrome (CDS) is a progressive, age-related neurodegenerative condition in dogs and cats. In some ways, it’s similar to dementia or Alzheimer’s disease in humans.
CDS affects brain function. It changes the way our pets remember, learn and adapt to changes in their home environment and routines. They may get lost or confused easily and struggle to remember routines they’ve had for years. Their behaviour and personality can also change.
IMPORTANT: There are many diseases that can look like Cognitive Dysfunction Syndrome, but their causes and treatments are different. If you suspect your older pet has signs that appear to be CDS, it’s important to get them checked out by a vet to rule out other issues.
How do we diagnose cognitive dysfunction?
It’s difficult to do this. There is no single test we can run to confirm CDS.
Typically, we make the diagnosis by ruling out other medical conditions, and by observing the behavioural changes over time.
Because there are many diseases that can look like CDS, a thorough veterinary examination (including physical exam, bloodwork, and urine testing) is essential.
What should you look out for as a pet owner?
We’re looking out for DISHA – Disorientation, Interaction changes, Sleep-wake cycle changes, House soiling, and Activity level changes.
D – Disorientation
- Getting lost in familiar places.
- Going to the wrong side of doors.
- Staring off into space for long periods.
- Not recognising familiar people or environments.
I – Interaction changes
- Altered social behaviour with owners or other pets.
- Increased clinginess, wanting to be around you all the time, or
- Being more withdrawn and keeping away from people.
- Irritable when approached or petted.
S – Sleep-wake cycle changes
- Sleeping more during the day.
- Restlessness or waking at night – pets with CDS can be distressed and seem lost and confused at night.
- Disrupted or irregular sleep patterns.
H – House soiling
- Peeing or pooing indoors, or in unusual places.
- Loss of previously learned toilet habits.
- Not letting you know they need to go outside.
A – Activity level changes
- Decreased activity or play.
- Increased restlessness, wandering, or repetitive behaviours (e.g., pacing around, licking).
Some other common signs that we see in CDS cases:
- Anxiety and agitation (vocalisation/crying, fearfulness, increased dependence)
- Learning and memory decline, this can look like:
- Difficulty learning new tasks.
- Forgetting previously learned behaviours.
- Slower adaptation to routine or environmental changes (e.g., getting lost/confused after you’ve moved furniture around).
At what age does cognitive decline begin?
It can begin quite a bit earlier than you expect. The signs are often very hard to notice at first. Over time, they become more obvious.
In dogs:
- Declines in learning and memory can start to be seen around 7 years of age, with clinical (noticeable) signs often appearing later.
- In older dogs (11–16 years), studies show a high proportion of dogs have at least one sign of CDS.
In cats:
- Around 35% of cats aged 11–15 years show signs of CDS, and this increases to
- Up to 50% of cats over 15 years show signs
It’s not always CDS
What makes CDS tricky to diagnose is that there are a number of diseases that have similar signs.
For example, a cat with pain from arthritis can pee/poo in inappropriate places (it’s hard to get into the litterbox or outside), they may sleep more, and be less active (because moving is harder and painful).
A dog with hearing issues may struggle to learn new tasks or not respond to you in the normal way (they’re not confused, they just can’t hear you the way they used to).
It’s important to rule out other conditions, including:
- Pain (e.g., arthritis, dental disease)
- Sensory decline (hearing or vision loss)
- Infections (e.g., urinary tract infections)
- Organ disease (e.g., liver or kidney disease)
- Hormonal disorders (e.g., Cushing’s disease)
- Changes in household routine or environment
A thorough veterinary evaluation is necessary to distinguish CDS from these conditions.
Can CDS be treated?
There is no cure for cognitive dysfunction, but early intervention can slow the progression and improve quality of life.
Management typically involves a combination of approaches, including:
Grade and monitor the severity of the signs
This gives a baseline to refer back to.
Medication
Certain medications may improve brain function or slow decline; these are prescribed by a veterinarian.
Manage any other diseases that can make CDS signs worse.
Some common ones we see are:
• Obesity
• Hypertension (High blood pressure)
• Dental disease
• Osteoarthritis
• Chronic inflammatory diseases
Specialised diets and supplements
Research has shown that diet can slow and even reverse cognitive decline – especially in dogs. The current research indicates that there are supplements and diets that can support brain health by increasing particular nutrients used by the brain.
So far, the following has evidence to support use in pets with cognitive decline.
DHA
This is a lipid that is used in repairing brain tissue, and it helps to reduce inflammation. It’s an omega-3 fatty acid found in fish oil.
A mix of antioxidants
There’s a range of antioxidants that have shown benefits in brain health. Some of these include Vitamins C and E, selenium, lycopene, and curcumin, which is a polyphenol found in turmeric. The benefit seems to be found in the mix of these antioxidants rather than one over another.
For more information about this, we recommend you talk to a veterinary nutrition specialist about your pets specific needs.
Feeding schedule changes
Changing dogs to a once-a-day, limited-time feeding diet has also shown benefits. The quantity of food given doesn’t change, but you effectively put your dog on an intermittent fasting diet.
For cats:
There’s very little research available for cats with CDS, but based on what we do know, we suggest talking to your vet about DHA and antioxidant supplements.
Once-a-day feeding has NOT shown any benefits in cats. We do not recommend reducing the frequency of feeding your cat.
It’s important to get your pet checked out by a vet BEFORE changing their diet if you suspect any cognitive decline. These diet changes aren’t suitable for all pets. Your vet can advise on diet changes and recommend supplements and foods with evidence behind them.
Increasing Mental and physical stimulation for your pet
This is a critical recommendation. All the medication and diet changes in the world cannot help a pet that isn’t getting enough mental stimulation.
You can help your pet by:
- Regular exercise (adjusted to your pet’s physical ability)
- Play sessions and interactive toys
- Continued training and learning activities
- Social interaction with owners and other pets
For cognitive function, “use it or lose it” very much applies.
Managing specific signs
Signs like anxiety, sleep disturbances, or restlessness may require behavioural strategies or medication. This is a discussion to have with your vet.
Adjustments to routines can also help stabilise behaviour.
Supporting your pet at home
Practical adjustments can greatly improve quality of life:
For dogs:
• More frequent bathroom breaks
• Dog doors or easy outdoor access
• Indoor toileting options if needed
• Dog nappies in some cases
• Changes to diet and/or feeding schedule (if advised by your vet, with proper monitoring)
For cats:
• Additional litter boxes
• Larger or low-sided litter boxes for easy access
• More frequent cleaning
• Easy access placement
• Changes to diet through new food or supplements (if advised by your vet, with proper monitoring)
Mobility and sensory support:
• Ramps or assistance for stairs
• Comfortable, easily accessible resting areas
• Improved lighting if your pet also has vision loss
• Consistent layout to reduce confusion
Can cognitive dysfunction be cured?
CDS cannot be cured, BUT early detection and a combination of:
• Veterinary care
• Diet and supplements (when appropriate)
• Medications (when appropriate)
• Environmental and behavioural support
• Management of other underlying diseases
Can help slow progression and improve your pet’s quality of life and daily functioning. The research shows that it is the combination of changes, which includes both diet and mental stimulation, that has the greatest effect on pets with CDS.
If you have any concerns about an older pet, make an appointment with your vet, and let them know what you’ve seen.
Early intervention can significantly improve the quality of life and help pets remain comfortable and engaged in their senior years.
