Page 428 - Cote clinical veterinary advisor dogs and cats 4th

188 Cognitive Dysfunction

Cognitive Dysfunction Bonus Material
Online
VetBooks.ir Etiology and Pathophysiology

BASIC INFORMATION
• Dogs, like humans, develop amyloid plaques MRI (p. 1132) may be indicated. If MRI
shows only increased ventricle size and all
Definition in the brain, the density of which appears to other laboratory and physical findings are
The decline in behavioral condition with roughly correlate with the level of impairment. unremarkable, a presumptive diagnosis of
advanced age, in the absence of causative • Unlike humans, dogs/cats/rodents do not cognitive dysfunction may be made.
physical or medical conditions appear to develop neurofibrillary tangles • Activity monitors may show changes in
associated with the tauopathy Alzheimer’s patterns of recent activity (more starting
Synonyms disease. and stopping, more ritualized behaviors)
Senility, cognitive dysfunction syndrome • Cats and dogs experience a decrease in and altered sleep patterns.
(CDS), brain aging brain cortical mass and a relative increase
in ventricular volume with aging. These TREATMENT
Epidemiology changes may be more extreme in patients
SPECIES, AGE, SEX with cognitive dysfunction. Treatment Overview
• Cats: typically > 10 years old Goals of treatment are a decrease in the rate
• Dogs: typically > 6 years old (large breeds), DIAGNOSIS at which the animal appears to mentally fail
> 12 years (small breeds) and relieving pain and distress associated with
Diagnostic Overview changes in physical and mental status. Early
GENETICS, BREED PREDISPOSITION Cognitive dysfunction is an insidious-onset, intervention (e.g., nutritional/nutraceutical
Dogs and cats, like humans, may have suscep- slowly progressive disorder that is almost always support to combat effects of reactive oxygen
tibility genes for the development of lesions suspected based on history and signalment species (ROS), routine aerobic exercise and
associated with clinical cognitive syndromes. (geriatric patient). Emphasizing problem solving cognitive and olfactory stimulation) may have
The understanding of tauopathies that exists and cognitive tests, including the emphasis on a protective effect as for humans and mice. All
for human medicine does not currently exist nosework, offers an opportunity for diagnostic treatment modalities (behavioral, nutritional,
for veterinary medicine. insight. Routine tests are indicated to identify medication, environmental) should be used
confounding systemic metabolic abnormalities, concurrently.
ASSOCIATED DISORDERS if any. Confirmation using brain imaging and
Concurrent anxiety-related conditions are cerebrospinal fluid (CSF) analysis is undertaken Acute General Treatment
common. only if the clinical picture suggests a different • Avoid exposure to stimuli known to cause
disorder is possible (e.g., cranial nerve or other distress.
Clinical Presentation deficits are more consistent with a disorder • Early rewarding of any normal, preferred,
HISTORY, CHIEF COMPLAINT other than cognitive dysfunction). Nonspecific or good interactive or elimination behaviors
• Disorientation (confusion at doors/ brain shrinkage is the absence of other notable and encouraging normal locomotion
accessways), changes in social and interactive lesions on MRI and may be linked to cognitive • There should be absolutely no punishment—
behavior (becoming needier or, conversely, changes. physical, verbal, deprivational, or mental—
more aloof), changes in locomotor (nonfunc- for any undesirable behavior that occurs as
tional repetitive movement) and sleep cycle Differential Diagnosis a result of this condition. Such actions will
(disrupted sleep cycles and Diehl behaviors) • Generalized anxiety disorder render the patient more anxious.
behaviors, and loss of housetraining • Anxiety: usually transient; associated with • Protect the patient from wanderings or odd
• In early cognitive dysfunction, animals may changes in physical capabilities (e.g., behaviors while keeping it comfortable. The
have only slightly altered sleep cycles and diminished or changing sensory or locomotor latter may involve containing it in an area
appear more anxious. capabilities) with an absorbent surface when left alone.
• Separation anxiety: old-age onset • Mental stimulation in the early stages is
PHYSICAL EXAM FINDINGS • Panic disorder important and may delay clinical progres-
• May be unremarkable • Attention-seeking behavior sion. Treat balls, food toys, games involving
• Possible abnormalities include worn claws or • Meningoencephalitis puzzle solving, safe exercise, interactive tasks
acute superficial erosions of the nasal planum • Hepatic encephalopathy (e.g., “get the mouse,” “bring the ball”), and
if trapped in corners or if exhibiting ritualistic • Brain neoplasia olfactory stimulation are useful.
locomotor behavior. • Hyperthyroidism (cat), hypothyroidism (dog) • Omega-3 fatty acids (1500-2000 mg/day)
• Weight loss (from excessive locomotion and/ may aid in protection from neurocytotoxic
or inappetence due to anxiety) Initial Database damage.
• When examined on video, the behaviors • CBC, serum biochemistry profile, and
exhibited by an animal with CDS often seem urinalysis: generally unremarkable Chronic Treatment
without purpose; in extreme cases, animals • Neurologic examination (p. 1136): generally • Physically and mentally stimulating exercises,
appear to be moving as if they cannot stop unremarkable such as swimming, massage, range-of-motion
or staring blankly. • Thyroid profile: rule out hyperthyroidism exercises
• Frank mentation changes may be apparent (cats) or hypothyroidism (dogs) • Encourage relaxation.
when asked to solve problems/puzzles or • Starting at middle age, screening for deficits • If loss of housetraining occurs, ensure that the
orient. Physical aging affects speed, not should occur at every visit. animal is taken out frequently and reward as
accuracy, of problem/puzzle solving. Cogni- for a young pup; if needed, clip and diaper
tive dysfunction affects accuracy and interest. Advanced or Confirmatory Testing dog to decrease client and dog distress.
• May have testable changes in response to • If neurologic signs are present, a full neu- • Encourage re-establishment of daily cycles
olfactory stimuli that would have caused a rologic evaluation, including CSF analysis by feeding at regular hours and at least a
response earlier in life. (pp. 1080 and 1323) and brain CT or few hours before bedtime, and administer

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