Cognitive Dysfunction In Old Dogs

Updated November 10, 2021

The loss of mental function with age is one of the hardest parts of dog ownership. To some extent it’s unavoidable, but there’s also a lot you can do.

The most important thing is knowing when it isn’t likely. I see far too many dogs written off with ‘dementia’ who really have something else entirely. Usually something that can be treated.

Let’s start by naming it properly: it isn’t sundowners, or Alzheimer’s or even dementia. We call it Cognitive Dysfunction Syndrome or CDS.

Symptoms Of CDS

Signs of CDS do not normally appear until over 13 years of age. They include:

  • Wandering and unsettled behaviour at night
  • Getting lost or disoriented in the house or yard
  • Unexplained anxiety or stress
  • Loss of learnt behaviours like toilet training
  • Reduced interaction with people or other animals
  • Reduced activity and sleeping more

Any other symptoms such as seizures or aggression are more likely to be due to something other than CDS.

What Else Could It Be?

Many other diseases can mimic the signs of CDS. Therefore it’s often a diagnosis made by exclusion.

CDS should never be diagnosed without the assistance of a vet. I am always especially suspicious of another cause in any dog under 14.

So once you have a diagnosis, what can be done?

Treatment Of CDS

The most important aspects of treatment are:

  • Compassion: these dogs are often confused and just as unhappy as you about house soiling
  • Scepticism: while worth trying, many products fail to live up to their claims
  • Realism: although improvements can be expected, they are often small

Before discussing medications we should not overlook behavioural therapy. Examples include:

  • Promoting continued activity
  • Maintaining established routines
  • Practising previously learnt training commands
  • Use of puzzle feeders (appetite is usually good in CDS)
  • Use of a crate or den for night sleeping (if it was used as a puppy)

Then, before medication we need to rule out all the other diseases that could be mimicking CDS. This means we’re likely to recommend:

  • Fixing any bad teeth
  • A short trial of pain relief for arthritis
  • A blood test

Nutritional Supplements & Natural Remedies For CDS

All of these treatments have at least some evidence of efficacy and should be reasonably safe. Those marked with an asterisk (*) are not available in Australia but may be available online. The first four are used for cognitive impairment. 

  • Antioxidants (Hills Prescription diet b/d)
  • Medium chain triglycerides (Purina One Vibrant Maturity*)
  • Phosphatidylserine (Senilife*, Aktivait*)
  • S-adenosyl-L-methionine (Novifit* & Denosyl)

Read a detailed update of the nutritional treatments of CDS here. The next three are treatments for anxiety and sleep disturbances with very low levels of evidence.

While there’s no good rationale, I also give my old dog a dose of fish oil every day. It’s cheap, easy and harmless, and has been shown to help many other diseases of old age.

Medications For CDS

Of the drugs, Selegiline (Anipryl) and Propentofylline (Vivitonin) claim to improve the signs of CDS. My personal experience with these has however been disappointing, despite reasonable evidence for selegiline.

The remaining drugs are for treating anxiety or sleep disturbances. All of these can achieve success at times. 

  • Melatonin
  • Fluoxetine
  • Benzodiazepines
  • Gabapentin, Tramadol
  • Trazodone

CDS and Life Expectancy

Unlike similar diseases in humans, CDS almost never causes loss of vital functions such as the ability to eat. Therefore, a dog with cognitive dysfunction or dementia has a similar lifespan to unaffected dogs and can live indefinitely.

Consequently, it’s important to keep an eye on your dog’s quality of life. Unless another problem appears, it’s very unlikely your dog will just pass away in their sleep. Instead they can go for years, and be at risk of suffering.

As upsetting as it can be, at some time in the future you may want to talk to your vet about end of life decisions. I promise that if you do, your vet will not only give the best advice they can, but also have helped many dog owners before. We all want the same thing: the best life we can give them, for as long as we can without causing harm.

Have something to add? Comments (if open) will appear within 24 hours.
By Andrew Spanner BVSc(Hons) MVetStud, a vet in Adelaide, Australia. Meet his team here. The information provided here is not intended to be used as a substitute for going to the vet. If your pet is unwell, please seek veterinary attention.

14 Replies to “Cognitive Dysfunction In Old Dogs”

    1. Hi Vivi. I’m afraid it’s just a matter of searching for it as I don’t think it has a distributor here.

  1. Andrew,

    My little guy PONCHO has Cushings and Dementia.. He is
    on 5mgs. of Anapryl for a few months now, he seemed at first
    to be better however, he is now starting all over again to stare at
    wall, tuck in corner etc. Is there anything else I can give him?


    1. Hi Catherine. I mentioned quite a few other options in the article. I suggest you can talk to your vet about whether there are appropriate in your case.

  2. This information is excellent. Our 16 year old tenterfield commenced with dementia like symptons shortly after 2 other events. One was a tooth infection which led to gum issues and many extractions and the second was from pulling muscles in his lower back leadinf to an odd gait when walking( but not when running). He was put on selegiline. He vomited quite a bit and could have absolutely no dairy on this drug. We had to half the dose then slowly build it up to 3/4. Not seeing much improvement after 8 weeks. Taking him out to swim in the ocean seems more beneficial. I will now look into a potential underlying arthritis issue which has not been considered re his back injury.! I also clean his teeth daily to prevent further deteriation. Thank you for holistic approach!

  3. Our 14+ year old silky x became blind in January (cataracts) and was already deaf. How do you distinguish blindness disability from cognitive function problems? She tends to go round in circles unless she bumps against my leg while walking. Walking is very slow but sniffing is popular. On her own in the garden she eventually finds her way back. She absolutely loves her food. Blood tests were OK. Quality of life good enough???

    1. Hi Simone. Unfortunately, quality of life is impossible to judge from appetite alone, as even dogs with advanced CDS still seem to eat well. Your issue with blindness and cognitive decline occurring simultaneously is very common and each tends to make coping with the other worse. It’s a bad combination. Judging quality of life in these situations is very hard and probably relies a lot on how well they interact with their owners.

  4. Out of selegiline and vivitonin however, which would you opt for first. Or can they be used together?

  5. I wanted to thank Andrew for his information on Cognitive Dysfunction. It is very well written and has given me more insight than several trips to my own Vet has achieved. I understand now that end of life is probably the kindest thing to do for my 16 year old Griffon who has not improved with any of the treatments tried. He has very simply hit on the perfect wording in this article. I am very grateful.

  6. Great page.
    Thank you.
    I have a gorgeous little dog who has a grade 4 heart murmur and is on heart tablet from my vet. I would like to know if there is anything I can give her when she has to go to the groomer to keep her calm so she doesn’t have a ‘faint’ or ‘seizure’.

    1. Yes there is – I would talk to your vet about either of clonidine, trazodone or gabapentin as options.

  7. Im pretty certain that our boy 13 turning 14 is suffering with dementia. He presents with all the signs, and now the night restlessness is happening, he is pacing, barking and howling.. I have not taken him to the vets but I will be making an appointment asap. Im hoping that some medication will help relief him.

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