Aging Gracefully by Dr. Cindy Krane
It is widely accepted that dogs age more rapidly than people and on average have a shorter life span. It was thought that for each year that a human aged a dog aged seven years. We know now that way of measuring a dog’s age is inaccurate. A more accurate calculation of a dog’s age is as follows: the first and second years of a dogs life are each equivalent to 10 years of a humans life. The following years of a dog’s life are equivalent to 4–6 years of a human’s life depending on the size and breed of the dog. Thus an 8 year-old dog is equivalent in age to a 45–65 year old person.
The life expectancy of a dog is based on many factors. Prime factors include size (smaller dogs tend to live longer), sex (female dogs live long then male dogs; like women and men), and reproductive status (neutered dogs live longer than intact dogs). Other mitigating factors include, breed, genetics, lifestyle, diet, exercise, and quality of medical care they receive.
Dogs over the age of 7 or 8 are considered “senior”. As such they are prone to certain ailments. As your dog approaches or navigates through his/her senior years note any changes in weight, appetite, urination, or water consumptions. Note any loss of strength, agility, or development of weakness, tremors, shaking, and stiffness. Note any decreased in vision or hearing. Note any repetitive or compulsive behaviors like pacing, licking, vocalizing, or nighttime waking. Bring any of the above changes to the attention of your veterinarian immediately. Old age, in itself is not a disease. Sure, you can expect them to slow down, develop some graying fur around the face and some bluing of the eyes. Be careful not to fall into the trap of ignoring subtle changes or chalking them up to “old age”. Below are some diseases that become more prevalent with age.
Cognitive Dysfunction Syndrome, also known as canine cognitive dysfunction (CCD) is similar to senility and dementia in people. It affects elderly pets and progresses slowly over 18–24 months. Although not full understood it is though that the brain becomes less attentive to stimuli as it ages. The actual mass of the brain and the amount of oxygen it receives decreases with age. It can cause, in some cases, disorientation where dogs get lost in a familiar environment or on a familiar route. For example they get stuck under a table, in a corner, or on wrong side of the door. Other dogs become less interactive; show loss of interest petting, and human contact. Some dogs show alterations in daily activities, awareness, and ability to learn and remember things. Still another manifestation of CCD is house soiling in dogs that have been previously potty trained. Many affected dogs develop alterations in their sleep–wake cycle. Increased need for more frequent eliminations, pain and restlessness cause nocturnal wakefulness. Options to slow the progression CCD are 1) maintain exercise 2) maintain stimuli (novel toys, food puzzles, stuffed Kongs, training, playing) 3) modify diet by adding fatty acids to promote cell health, anti-oxidants to reduce toxic effects of free radical to the diet and 4) medications like Novifit and Anipryl to increase cognitive function.
Chronic Renal Failure (CRF) is one of the most common diseases of senior dogs; increasing in prevalence with age. Clinical signs include increase thirst, increased urination, vomiting, diarrhea, weight loss and inappetance. Secondary hypertension can occur with renal disease. While there are many causes of renal failure for the purpose of this article I am referring to the normal aging process where by renal function decreases with age. Before blood work shows elevation in renal values 75% of kidney mass is no longer functioning. CRF can progress over months to years and is ultimately fatal. It can be slowed down with the modification of diet (restrict protein and phosphorous, increase water intake) and administration of fluids. Diuresis (extra fluid beyond what the animal can drink) can be provided to help the kidneys get rid of toxic waste. Your primary care veterinarian can do this. Dialysis (hemodialysis) where waste products are actually cleansed from the blood is offered only at tertiary care facilities and is very invasive and expensive. The only definitive treatment or “cure” is renal transplantation, which are available only at large teaching hospitals.
Osteoarthritis (arthritis) commonly affects geriatric patients. Hips, knees and/or elbows are the most commonly affected joints. Most geriatric dogs, especially large breed dogs, have radiographic evidence of arthritis. Owners typically notice pain, lameness, and difficulty rising exasperated by long periods of recumbancy, cold weather, and exercise. Unfortunately this too is a progressive disease process. Treatment modalities are aimed at alleviating pain and slowing progression. Medications (vitamins, nutrapharmaceuticals, and prescription medications), diet, weight loss, physical therapy, modified exercise (20 minutes daily), harnesses, slings and comfortable bedding to alleviate pressure on joints, and surgical intervention are all options. Convert stairs to ramps, slippery tile floors to carpeted areas, and elevate food bowls to make navigating around their home more comfortable.
Many geriatric dogs suffer from loss of senses; hearing and vision. Owners may notice that their dog no longer responds to his/her name, or is difficult to wake from a sleep. This type of deafness is called presbycusis, a senile of degeneration of parts of the hearing apparatus. Dogs can be retrained to respond to hand signals and sense vibrations to compensate for their hearing loss. Likewise can be walked on a harness in a well-lit area and kept in familiar, consistent surrounds to help compensate for vision loss.
Cancer, cardiac, dental and endocrine diseases (thyroid, diabetes, Cushing’s) are all also over represented in occurrence amongst senior dogs. As such it is important for semi annual routine veterinarian examinations. Your veterinarian may recommend blood work (for organ and thyroid function), urinalysis, blood pressure, and imaging (radiographs and ultrasound) as part of a senior screening process. While many diseases that plague geriatric dogs can’t be “cured” early treatment intervention can help to extend their life expectancy while ensuring and maintaining an excellent quality of life.