Veterinary Medicine - July 2008 - (Page V2)

S-adenosylmethionine (SAMe) and cognitive dysfunction in dogs increase in repetitive activities or decreased overall activity). What are the most common signs associated with early cognitive dysfunction? Dr. Amanda Florsheim: Dogs are usually presented to me because of housesoiling or a disturbance in their sleep-wake cycle. These signs disrupt owners’ lives, so they are what general practitioners see. Landsberg: Owners don’t always report these subtle signs. Do you have any suggestions for identifying these signs as early as possible? Florsheim: At my clinic, we are implementing a standard questionnaire for dogs older than eight years. This form asks questions about these subtle signs, such as: Have you seen a decrease in play? Does your dog seem to sleep more during the day? We ask about subtle signs early, rather than waiting for the more dramatic signs to appear later. Dr. Valerie Dramard: As the disease progresses, disorientation becomes another sign of cognitive dysfunction. The dog gets lost in the garden or in its neighborhood. Or when you open the Florsheim: We run a complete blood count, serum chemistry pro le, urinalysis, and urine culture to rule out as many medical causes as we can. We also conduct a thorough neurologic exam. Landsberg: You should do a complete workup that is not more extensive than necessary. In some cases, an MRI or CT scan might be appropriate, whereas in cases with no neurologic abnormalities or with signs related to other organ systems, these tests might be unnecessary. Several years ago, I was on a panel of the American Animal Hospital Association that set up senior care guidelines. Those guidelines recommend annual examinations at middle age and twice-a-year examinations as pets reach their senior years. This is the time to take a good behavioral history. It is critical to talk with the owners at every year’s checkup—these are the pet’s caregivers. Dr. Teodoro Bottiglieri: In human medicine, the term dementia comprises many di erent types of cognitive dysfunction. The most common form is Alzheimer’s type dementia, which makes up 70% of all cases. The pathologic hallmark of this form of dementia is the deposition of beta-amyloid protein in the brain, which leads to the formation of senile plaques. Studies in dogs have shown that beta-amyloid protein and plaques are present in the brain and as in humans the amount of beta-amyloid burden is correlated with the degree of cognitive decline. The second most common form of dementia in humans is vascular dementia occurring in about 17% of all cases. In aged dogs cerebral vascular changes can also be present. Landsberg: Dogs do not progress to the full Alzheimer’s changes and don’t develop such irreversible or major changes like people do. That’s why they are used as models for early Alzheimer’s changes and why therapeutics might be more e ective in animals. Numerous vascular changes have been identi ed as well. A couple of the therapeutics available in Europe for dogs are directed at treating blood ow changes in the brain. Dr. David Mischoulon: It is striking how similar the presenting clinical signs are for cognitive dysfunction in dogs and people. In people, we see a lot of the same problems with sleep abnormalities, changes in activity, and disorientation. We also note a couple of di erences. First, soiling is usually not a problem in Alzheimer’s patients until very late in the disease. Second, people have a tremendous capacity for denial, which a dog doesn’t have. The dog cannot deliberately try to hide its de cits, compensate for them, or argue with you when you tell them something is wrong. Sometimes it is hard to convince families that this is a dementia and requires treatment. Are dog owners prone to denial when they start seeing problems in their pets? Florsheim: Many are and some don’t bring up problems with their veterinarian because they think the pet is just getting older. Pets and people Landsberg: Dogs have been used as models for aging in people for about 15 years. Dogs do not get Alzheimer’s disease per se; but they do undergo brain changes similar to the early changes in Alzheimer’s disease. Using “If we can get owners to understand the disease process, the signs to look for, and the fact that therapies exist, they might volunteer the information much earlier.” - Dr. Gary Landsberg door to let it outside, the dog is on the wrong side, standing next to the hinges. That is quite bizarre to owners. Diagnosis Landsberg: If a dog is brought in for housesoiling or night waking, how would you determine it has cognitive dysfunction, as opposed to some other problem? neuropsychological tests, researchers have found memory and learning de cits beginning as young as 6 years of age. Researchers have also examined the brains of older animals and have found increasing ventricular size, neuronal loss, and an increasing beta-amyloid deposition.2 How does that correlate with your knowledge of changes in the brains of people with Alzheimer’s? 2

Table of Contents Feed for the Digital Edition of Veterinary Medicine - July 2008

Veterinary Medicine - July 2008 Contents Leading Off Practical Matters Idea Exchange Clarification Dental Corner The Diagnostic Approach to Hematuria Guidelines for Evaluating Hypercalcemic Cats CE Form Advertiser Index Marketplace/Classifieds Mind Over Miller

Veterinary Medicine - July 2008

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