Cognitive dysfunction syndrome


Cognitive dysfunction syndrome (CDS) is a progressive neurodegenerative disease that leads to a deterioration in the cognitive abilities related to age. It is characterized by changes in behavior for which no medical cause can be found.

Contrary to popular belief, the signs associated with CDS are not normally related to aging, but constitute a disease in itself. CDS is the canine equivalent to Alzheimer disease.

A study conducted at Davis University in California reported that 62% of dogs aged between 11 and 16 years of age demonstrate signs in at least one of the categories of CDS. Following a survey carried out by the pharmaceutical company Pfizer with dog owners, practically 1 dog on 2 aged 8 years or more presented at least one sign associated with CDS.

Manifestations of cognitive dysfunction syndrome

Here is a chart to evaluate if your dog presents signs related to CDS. It will be very useful for your veterinarian in the framework of a geriatric evaluation of your pet.

Disorientation (spatial or temporal)

  • Your dog appears lost or confused at home or outside?
  • Your dog wanders without purpose?
  • Your dog remains wedged behind a piece of furniture or in a corner?
  • Your dog does not recognize familiar people?
  • Your dog does not respond to his name or to familiar commands?
  • Your dog has difficulty finding the door to go outside or if he finds it, he tries to get out on the side of the hinges? Your dog does not ask for the door in the usual places?
  • Once outside, your dog seems to have forgotten why he asked for the door?

Change in social interactions

  • Your dog asks for less affection than before?
  • When you are petting your dog, he spontaneously leaves?
  • Your dog seems less happy to see you?
  • Your dog does not always greet you when you return home (he knows that you are back)?

Change in sleep/wake cycle

  • Your dog sleeps less at night?
  • Your dog sleeps more in a period of 24 hours?
  • In a period of 24 hours, your dog is less active?
  • In a period of 24 hours, your dog roams more?

Loss of elimination habits

  • Your dog urinates or defecates indoors?
  • Your dog urinates or defecates indoors shortly after being taken out?
  • Your dog forgets to ask you for the door so he can go outside to do his business?

The causes

  • Deposits of amyloid plaque which have a localized inflammatory effect and are neurotoxic.
  • Increase in oxidative damage following an increase in the number of free radicals combined with a decrease in the efficiency of antioxidant mechanisms.
  • Decrease in cerebral perfusion (arteriosclerosis, cerebral ischemia, chronic hypoxia secondary to anemia, a cardiomyopathy, hypertension, a coagulopathy…)
  • A decrease in the number of neurons (secondary to hypoxia and a neurotoxicity) as well as an increase in glial cells.
  • Decrease in the concentration of neurotransmitters (acetylcholine, serotonin and dopamine).
  • Increase in the concentration of oxidase B monoamines and a decrease in the concentration of dopamine.
  • Anemia.
  • Hypertension (due to a kidney problem, hyperthyroidism, diabetes, etc…)