Is Your Dog Senile?

Digg

Del.icio.us

Stumble

Is Your Dog Senile?

By: Dr. Nicholas Dodman

See Larger Image

There is nothing unusual about growing old. It happens to the best of us. Nevertheless, most of us don't enjoy watching the aging process occur in ourselves and in our loved ones. And similarly, we don't like to see our pets grow old.

As veterinary medicine has become more sophisticated, and careful nurturing of pets has become the rule rather than the exception, the population of geriatric small animal pets has grown steadily, mirroring the increase in the human elderly population. As an animal advances into the twilight years, inevitable aging changes take place in all organ systems, including the brain.

Dogs are considered geriatric when they reach 10 years of age, or when 75 percent of their anticipated life span has elapsed. This does not mean that when they have exceeded this arbitrary limit they will automatically show signs of senile dementia.

Some dogs appear normal cognitively long after the empirical cutoff, and some remain bright to the end of their life span. Such dogs are referred to as "successful agers," same as their human counterparts. Dogs that do not weather the aging process well and who show obvious signs of mental deterioration constitute the unsuccessful agers.

The Signs

Though variable in degree and expression, the classical signs of cognitive dysfunction (CD) in elderly dogs include:

Reduced activity

Increased sleeping

Reduced responsiveness to commands/apparent deafness

Lack of interest in surroundings/events

Confusion/disorientation

Inability to recognize familiar people

Increased thirst

Excessive panting

Difficulty eating and/or reduced interest in food

Loss of bladder and bowel control

Difficulty navigating the environment (e.g. stairs)

Not all dogs show all of these signs and some also show paradoxical behavior, such as agitation and/or barking for no particular reason. The clinical signs of CD are progressive and will eventually incapacitate the dog. It is interesting to note that the percentage of dogs affected at 10 years old, 12 years old, or 14 years old, mirrors the age-related demographic for cognitive dysfunction in humans.

Central Nervous System

Though not identical to the changes in human Alzheimer's disease, the changes in the brains of dogs with CD are similar to those in Alzheimer's and are found in proportion to the severity of the clinical syndrome. Many different neurological changes have been reported in canine brains, the most significant of which are deposits of beta-amyloid and its formation of plaques. These pathologic changes are thought to be responsible for the observed cognitive/behavioral deterioration.

The Cause

Changes in the brain may be responsible for CD but we don't know why they occur. Genetics probably play some role. However, an interaction between genetics and the environment cannot be dismissed, and management factors, such as excessive vaccination and environmental stress may also be part-responsible.

Treatment

There was no treatment for this degenerative condition until the advent of deprenyl (Anipryl®), a drug that has helped turn back the aging clock and buy affected dogs more quality time. Deprenyl is not a primary cure but reverses the clinical signs of aging by increasing brain concentrations of the neurotransmitter dopamine. Dopamine is a neurotransmitter that connects thought with action and increases cognitive awareness. In the Oliver Sack's movie, Awakenings, patients could not move because of the lack of dopamine. Dopamine is low in Parkinson's disease, a condition in which patients have difficulty moving, and who also eventually have cognitive impairment. In contrast, excessive dopamine levels produce racing thoughts, paranoia, increased anxiety and repetitive behaviors. If the canine aging theory is correct, CD patients have low dopamine, hence low activity and cognitive performance. Increasing dopamine by means of deprenyl reverses signs of CD in a good number of canine CD sufferers. One third of affected dogs respond extremely well to treatment with deprenyl, regaining their youthful vigor; another one third respond reasonably well; and one third do not respond at all (perhaps there is a variant of CD with different neuropathology). The bottom line is that for any dog that is slowing down to the point that problems become apparent, treatment with deprenyl is the logical route once other organic causes for reduced mental function have been ruled out.

Many people think that it is "normal" for their elderly dogs to lose energy and interest in life and tolerate the cognitive aging syndrome far longer than necessary. These folk either don't seek help or wait until bladder or bowel control is gone before seeking an opinion. The latter is the main cause for concern for owners of geriatric dogs, who can tolerate almost any amount of senile change in their pets before the indignity of incontinence finally causes them to seek help.

Deprenyl is marketed with the specific label instruction for the treatment of age-related cognitive dysfunction and age-related inappropriate urination and early treatment with the drug will buy impaired dogs extra quality time increasing their "health span." As a side effect, deprenyl also increases the life span of dogs over 10 years.

A new method for the prevention and/or treatment of CD in dogs is a dietary one. Hills Petfood has introduced a prescription diet called Hills BD (brain diet). The diet is rich in antioxidants and slows the progressions of CD by inhibiting the physical damage caused by the accumulation of "free-radicals" in susceptible dogs aging brains. Furthermore, this dietary treatment may also help reverse signs of CD in some affected dogs.

Printable Version

Digg

Del.icio.us

Stumble

Share this Article with a Friend Email To:

Have a Pet Question?

Send Your Pet Question to Dr. Jon
and His Staff of Veterinarians

Dr. Jon's Newsletter

Yes! Send Me the Latest Health Information, Pet Tips, Pet Stories and more...

Search Over 15,000 articles

1 Like a Thief in the Night – Caring for Your Elderly Dog
They say old age creeps up on a person like a thief in the night. This is especially true of your dog. Dogs seemingly race through adolescence and adulthood, and suddenly at around 12 years of age, they...
Read More
2 How Old is This Dog?
Determining the age of an adult dog is not an exact science, even among veterinarians. But there are some physical clues that will help you determine your dog’s age.
Read More
3 Feeding Your Adult Dog
Good nutrition and a balanced diet are essential elements for good health in your dog. That means watching your canine’s caloric intake carefully.
Read More
4 How Age Affects Your Dog
From cancer and deteriorating thought processes to arthritis and diabetes, geriatric dogs develop diseases similar to those that befall humans. Here is what you might encounter.
Read More
5 Keeping Your Senior Dog Healthy
Your dog's breed and size determine when he enters his senior years. You can't hold back the clock, but there are many things you can do to help keep him healthy and active as long as possible.
Read More
6 How Long Will My Dog Live?
Just like people, dogs slow down as they grow older. Their hair turns gray, their eyes dim, their bodies lose tone. The old rule that one dog year equals seven human years is not exact. The ratio is higher...
Read More

Over 10,000 Veterinarian Approved Articles

Dogs & Puppies

Dog Breeds

labrador retriever, golden retriever, yorkshire terriers, german shepherds, beagle, boxers

Dog Medication

dog allergy medication, dog pain medication, dog anxiety medication, dog flea medication

Dog Products

dog bowls, dog crates, dog toys, dog beds, dog ramps, dog food storage, dog tags

Dog Symptoms

dog vomiting, dog limping, dog diarrhea, dog bad breath, dog coughing, dog seizures

Dog Health

dog cancer, dog diabetes, dog epilepsy, dog hip dysplasia, dog health, sick dog

Dog Care

dog vaccination, dog microchipping, dog grooming, dog neutering, dog spaying, dogs mating

Dog Training

dog aggression, dog barking, dog chewing, dog behavior, dog jumping, dog whisperer

Dog Pictures

puppy pictures, funny dogs, cute dogs, dog breeds, sleeping dogs, silly dogs, small dogs

Cats

Cat Breeds

persian, siamese cats, devon rex, ragdoll cats, sphynx, maine coon cat

Cat Medication

cat flea medication, cat heartworm control, cat tick medications

Cat Products

cat litter box, cat food, cat bed, cat flea collar, cat carrier, cat urine odor

Cat Symptoms

cat vomiting, cat limping, cat diarrhea, cat bad breath, cat coughing

Cat Health

cat health, cat liver cancer, cat diabetes, cat scratch fever, cat aids, sick cat

Cat Care

cat vaccination, cat grooming, cat microchipping, cat neutering, cat spaying

Cat Behavior

cat urine marking, cat furniture scratching, cat litterbox training, cat toilet training, cat fears

Cat Pictures

cute cats, funny cats, playful cats, fat cats, jumping cats, lazy cats, sleeping cats, cute kittens

1Like a Thief in the Night – Caring for Your Elderly Dog
They say old age creeps up on a person like a thief in the night. This is especially true of your dog. Dogs seemingly race through adolescence and adulthood, and suddenly at around 12 years of age, they...
Read More
2How Old is This Dog?
Determining the age of an adult dog is not an exact science, even among veterinarians. But there are some physical clues that will help you determine your dog’s age.
Read More
3How Age Affects Your Dog
From cancer and deteriorating thought processes to arthritis and diabetes, geriatric dogs develop diseases similar to those that befall humans. Here is what you might encounter.
Read More
4How Long Will My Dog Live?
Just like people, dogs slow down as they grow older. Their hair turns gray, their eyes dim, their bodies lose tone. The old rule that one dog year equals seven human years is not exact. The ratio is higher...
Read More
5Keeping Your Senior Dog Healthy
Your dog's breed and size determine when he enters his senior years. You can't hold back the clock, but there are many things you can do to help keep him healthy and active as long as possible.
Read More
6Feeding Your Adult Dog
Good nutrition and a balanced diet are essential elements for good health in your dog. That means watching your canine’s caloric intake carefully.
Read More

Is Your Dog Senile?

Is Your Dog Senile?

Related Articles

Over 10,000 Veterinarian Approved Articles