CPD ACCREDITED ARTICLE
Cognitive Dysfunction
in Geriatric Dogs and Cats
Van der Merwe L.L. BVSc Hons MMed(Vet) Small Animal Medicine, Department of Companion Animal Clinical
Studies (Outpatients), Faculty of Veterinary Science, [email protected]
Reviewed by: Dr Frederique Hurley BVSc, BVSc, MPhil, MANZCVS (Veterinary Behaviour)
Canine cognitive dysfunction is a neurodegenerative
disease very similar to Alzheimers in humans . It is
characterised by a gradual onset of cognitive decline
over a prolonged period (18 – 24 months).
The acronym DISHAAL has been used to describe the
categories of clinical signs shown:
D Disorientation (spatial disorientation and confu-
sion, increased anxiety or restlessness)
I Interactions are altered (decrease perception or
responsiveness)
S Sleep-Wake cycle alterations (night waking)
H House soiling (altered learning and memory)
A Activity level altered (purposeless, repetitive or
decreased activity)
A Anxiety level (vocalisation/fear)
L Learning and memory
Not all senior dogs develop cognitive deterioration
and in most they are mild but some pets do develop
overt cognitive dysfunction syndrome. Owners of af-
fected pets often find it increasingly difficult to cope
with the changes in their pets’ behaviour and the hu-
man-animal bond can be stressed or broken. Many
owners will need to make painful decisions based
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upon both their own and their pets’ quality of life. A
study showed that 28% of owners of dogs 10 – 11
years old report at least one sign of cognitive change
but this increases to 68% of owners of 15 – 16 year
old dogs. In pets which are trained - such as guide
dogs and working dogs - dysfunction may detected
at an earlier age. The most commonly reported signs
of cognitive dysfunction in dogs is aimless pacing and
wandering and staring blankly (91%) and avoiding be-
ing patted and difficulty finding dropped food (75%).
The typical age of onset of presentation of cognitive
decline in pets is traditionally set at about 11 years of
age, based on owner reports. When data from labo-
ratory animals studied with standardised assessment
tools are evaluated however, the decline is noted to
start at about seven years of age. This discrepancy em-
phasises the insidious nature of the change. Owners
do not usually present their animals to their veterinar-
ian vet for cognitive dysfunction as they assume the
changes are just unavoidable ageing.
It is thus imperative that veterinarians are proactive
in asking questions regarding changes in behaviour
during a consultation and also in educating their cli-
ents in this condition.