Page 691 - Small Animal Clinical Nutrition 5th Edition

716 Small Animal Clinical Nutrition

of CDS has not been systematically examined. However, in
Table 35-1. Behaviors evaluated in dogs to assess some cases, a magnetic resonance imaging (MRI) scan might
VetBooks.ir 1. Confusion, awareness, spatial orientation be useful for differential diagnosis. Imaging might allow prac-
age-related cognitive decline.*
Gets lost in familiar locations titioners to rule out alternative explanations for changes in
Goes to wrong side of doors (e.g., hinge side) behavior, such as the presence of gliomas, tumors or damage
Gets stuck and cannot navigate around or over obstacles due to stroke. Note that a normal MRI scan cannot be used to
Less responsive to stimuli rule out CDS. However, with increased age, there is a tenden-
Decreased recognition of familiar people, pets or places
2. Relationships and social behavior cy toward ventricular dilatation and neuronal loss. (See macro-
Decreased interest in petting or contact scopic changes below.) Although these changes might be
Decreased greeting behavior expected to correlate with increasing cognitive dysfunction, this
Alterations or problems with social hierarchy
In need of constant contact (e.g., over dependent or “clingy”) has not been validated. Traditionally, the signs of canine CDS,
3. Activity: Increased, decreased or repetitive hypothesized to be caused by brain aging, were described by the
Decreased daytime sleep/increased wandering or pacing acronym DISH. (See above.) Alterations in activity levels in-
Decreased exploration (apathy)
Staring, fixation or snapping at objects cluding increased restlessness and pacing have also been iden-
Licking owners or household objects tified; therefore, an “A” for activity has more recently been
4. Agitation or anxiety added to the acronym (Landsberg and Araujo, 2005; Lands-
Inappropriate vocalization
Restless sleep berg et al, 2003; Neilson et al, 2001; Osella et al, 2007). These
Increased irritability/aggression signs, however, do not necessarily reflect all of those associated
Aimless pacing and wandering with CDS and brain aging.
Increased/new fears or phobias
Separation anxiety In a review of 50 recent Veterinary Information Network
5. Appetite (VIN) postings of behavioral signs in senior dogs (aged nine to
Increased interest (volume eaten or speed of eating) 17), many of the reported problems were related to agitation
Decreased interest
Anxiety–conflict behaviors at food bowl and anxiety including fear, excessive vocalization, salivation,
6. Decreased responsiveness to stimuli destructiveness, hypervigilance, over-attachment, separation
May seem to have a decline in vision, hearing or odor perception anxiety, night-time waking and anxiety, restlessness, wandering,
7. Decreased self-care
8. Sleep-wake cycle pacing, confusion, noise phobias, increased sensitivity to sound,
Restless sleep or awake at night compulsive licking and aggression (sometimes concurrent with
Increased daytime sleep and sometimes independent of other signs of DISH). Each
9. Learning and memory
a) House soiling: Indoor elimination at random sites or in case received the guidance of one or more of the VIN special-
view of owners ists in neurology, internal medicine or behavior. Seizures,
Decreased or no signaling hypertension, sensory decline, arthritis, pituitary-dependent
Goes outdoors, eliminates indoors upon return
Elimination in crate or sleeping area hyperadrenocorticism and cerebral disease were the most com-
Incontinence monly suggested rule outs. There was no identifiable medical
b) Works, tasks, commands cause in 24 of the 50 cases, and medical problems were deemed
Impaired working ability
Impaired responsiveness to known commands or tricks unlikely to have contributed to the behavioral signs in another
Decreased ability to perform tasks nine cases. Of the remaining cases, arthritis, hearing loss, renal
Inability or slow to learn new tasks (must retrain) insufficiency, lymphadenopathy, mild anemia and pharmaceu-
*Adapted with permission from Landsberg G, Hunthausen W,
Ackerman L. The effects of aging on behavior in senior pets. tical therapy such as phenylpropanolamine and prednisone
Handbook of Behavior Problems of the Dog and Cat. were considered as possible contributing factors. This under-
Edinburgh, Scotland: Elsevier Health Sciences, 2003.
scores the importance of ruling out medical problems that
might cause clinical signs, and the fact that anxiety and agita-
tion are commonly reported signs in senior pets.
wellness screening for healthy middle-aged pets and twice year- A number of cognitive disorders have been described in the
ly screening for senior pets (i.e., last 25% of predicted lifespan). French literature including confusional syndrome, dysthymic
At each visit, the pet should receive a physical examination and disorder and involutive depression (which may be associated
laboratory tests and the owner should be extensively questioned with compulsive and stereotypical behavior, hyper-attachment,
about changes in behavior and health (Epstein et al, 2005). vocalization and anxiety) (Landsberg and Araujo, 2005). In
Most of these changes would not be detected during a veteri- addition, laboratory studies indicate that there is a measurable
nary visit because they can be intermittent, subtle in onset and decline in learning and memory associated with brain aging.
only noticeable in other environments. Therefore a senior care Laboratory-based systematic studies of changes in behavior
program should include use of a screening questionnaire (Table and cognition also provide evidence that behavioral changes in
35-1). (Landsberg and Araujo, 2005; Landsberg et al, 2003; senior dogs observed clinically have a neurobiological basis.
Pfizer Animal Health) and/or allow sufficient time for interac- Thus the acronym DISHA may not sufficiently and accurately
tive history taking. If problems are identified, early intervention reflect all of the clinical signs associated with brain aging and
may improve quality of life and longevity. cognitive dysfunction in older pets.Because these signs are gen-
The reliability and usefulness of brain imaging for detection erally noticed by pet owners and seldom in the veterinary clin-