Senior Dogs Are Being Diagnosed with Dementia, A Cognitive Dysfunction Syndrome That Can Be Treated

As dogs live longer, veterinarians are seeing more cases of dementia and other cases of Cognitive Dysfunction Syndrome (CDS) in various parts of the country. For example, around 10 percent of the senior pets examined by Barbara Eichler, DVM, in Missouri have dementia, a disease that has recently been identified in companion animals, and treated with the drug Anipryl. Eichler, owner of Community Animal Hospital in Missouri, questions whether dementia in dogs is a new disease or something that has simply been overlooked by the veterinary community.

“When you’re doing an exam on an older pet you should find at least four things that are not right,” Eichler said. “If not, you’re not spending enough time with them. The ones who are interested in older pets see the signs.”

Eichler believes that dementia is underreported by pet owners and doctors with dogs that present with symptoms that are attributed to old age or stubborn behavior. Signs of confusion or dementia may include wandering off while an owner is petting the dog, going to the wrong side of the door to greet an owner or go outside, and soiling inside after being outside.

Owners may attribute signs of dementia - like getting lost in the house - to old age, said Melissa Bain, DVM, a clinical veterinary behaviorist at UC Davis, who interviewed 150 owners of senior dogs in 2001 for a cognitive dysfunction syndrome study that she conducted with colleagues. "There is no definitive way to diagnose it until theyre dead," she said. However, a physical exam, blood panel, urinalysis, and neurological exam can rule out other medical conditions, such as brain tumors, diabetes, cataracts, and cardiac and kidney disease before treatment is initiated. "In humans dementia is also diagnosed by ruling out other diseases," Bain said.

Dementia in dogs is caused by a plaque formation in the brain that decreases the production of the neurotransmitter dopamine, Eichler explained. Anipryl, which is given in tablet form once daily, delays the breakdown of dopamine and allows the message from the brain to be received, she added. In addition to Anipryl, Bain noted that there is a brain diet produced by Hills Pet Nutrition that "slows down decline in elderly dogs." She also just completed a new study of how antioxidants can influence dementia, and hopes to share those results soon.

Time is of the essence with diagnosis and treatment since dogs can quickly slip into a zone that is more difficult to treat. That analysis is echoed by the research Bain and colleagues published in 2001.

Once other medical issues have been ruled out, Eichler has used Anipryl, a drug introduced by Pfizer Animal Health and approved by the Food and Drug Administration (FDA) for age-related behavioral issues. Anipryl was originally formulated for Cushing’s disease, but is used effectively at a lower dosage for dementia, Eichler said.

For some dogs, a prescription of Anipryl, marketed as Eldepryl for human use, can halt the progression of dementia, Eichler said.

“It’s been a miracle drug for patients whose owners thought they were beyond hope,” she explained. The only other behavior-altering drug for pets that has been approved by the Food and Drug Administration (FDA) is Clomicalm, though that drug is marketed for use with separation anxiety and urine spraying issues, according to Novartis Animal Health materials.

Eichler recommends that pet owners give an Anipryl tablet regularly at the same time of day – preferably in the morning. Depending on the size of dog, it costs about $80 for a one-month supply, which can be cost prohibitive. “Usually older dogs belong to older folks, who are sometimes on fixed incomes,” she added.

Anipryl is only available for dogs though Eichler has seen similar symptoms in cats.

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