Cognitive Dysfunction In Old Dogs

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. 

  • Unsettled sleep can be caused by pain or anxiety
  • Mental deterioration occurs with many illnesses such as diabetes, hypothyroidism, Cushing’s syndrome, liver or kidney problems
  • CDS is very hard to tell apart from vision or hearing loss
  • Severe dental infections can cause reduced activity or sleeping more

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. Not all are available in Australia or certain countries but you may want to try the few that are. The first four are used for cognitive impairment. 

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

The next three are treatments for anxiety and sleep disturbances with very low levels of evidence.

  • Theanine (Anxitane®)
  • Alpha casozepine (Zylkene®)
  • Pheromones (Adaptil®)

While there’s no evidence, 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 are welcome below and will appear within 24 hours of lodging.

By Andrew Spanner BVSc(Hons) MVetStud, a vet in Adelaide, Australia. These blogs are from a series regularly posted on Facebook and Twitter. Subscribe via email here to never miss a story!

Andrew

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