I stumbled on a great article today - thought I would share.  So appropriate for the zoo - my feline section is getting to the point that almost all of them are considered senior kitties:

Aging Changes In Cats

The Cat as a Senior Citizen
Age Conversion Chart
Common Changes in the Aging Cat
Detection of Geriatric Diseases

Aging is a natural process that we all experience. However, it brings with it some changes that are not particularly desirable. Forestalling and controlling certain aspects of the aging process are possible if appropriate intervention is undertaken in a timely manner. Our objective is to inform you of some of these methods for slowing the aging process.

The Cat as a Senior Citizen
back to the top

Cats age at a different rate than do humans. During the first year of life, a cat achieves adulthood. Therefore, that first year is equivalent to about 15 human years. The second year is equivilant to about 10 years. Each year then becomes the equivalent to about 4 human years. Based on that scheme, a comparison of feline and human years may be as follows:

Feline Age	Human Age
1 year	15 years
2 years	25 years
3 years	29 years
4 years	33 years
5 years	37 years
6 years	41 years
7 years	45 years
8 years	49 years
9 years	53 years
10 years	57 years
11 years	61 years
12 years	65 years
13 years	69 years
14 years	73 years
15 years	77 years
16 years	81 years
17 years	85 years
18 years	89 years
19 years	93 years
20 years	97 years

Based on this aging scheme, any cat over 12 years of age is deemed a “senior” cat.

Common Changes in the Aging Cat
back to the top

Many senior cats get a bit lazy in their grooming habits. They often begin to develop mats in their hair coat. Therefore, frequent brushing (1-3 times per week as tolerated by the cat) is important. Brushing collects the dead hair that would normally be removed by grooming, and it breaks down tangles before they become mats. However, occasionally it will be necessary to cut out a mat. Be very careful with scissors or clippers because many elderly cats have very thin skin that cuts or tears easily.

Senior cats also lose the desire or ability to sharpen their nails regularly. The nails become very thick because the dead nail tissue is retained. Failure to sharpen nails can also result in the nail curling backward into the footpad. This will be most uncomfortable and will result in lameness, bleeding, and possible infection. The key to preventing these problems is to cut your cat’s nails regularly (every 4-8 weeks).

Dental disease is common in older cats. The two most common forms of dental disease are tartar buildup, with resulting periodontal disease, and deep cavities near the gum line.

Tartar Buildup Tartar buildup is common in cats of any age, but older cats often have heavy tartar buildup due to years of dental neglect. The tartar irritates the gums, pushes the gums away from the roots of the teeth, and fosters growth of bacteria. Bacteria not only affect the mouth but they are also carried by the blood stream to other organs, most notably the kidneys (but also the heart and liver). Tartar buildup and periodontal disease are very treatable with proper cleaning and antibiotic therapy.

Feline Resorptive (Neck) Lesions, Cavities, that form at the gumline (gingiva) are called cervical line lesions or neck lesions. As they form, the gums may cover them; the gum then continues to proliferate over them. The cat’s mouth is very painful when that tooth is touched (even if done so under general anesthesia) and he or she may have difficulty eating. The only realistic treatment is extraction of the tooth. Attempts have been made to fill these cavities, but invariably these teeth undergo further deterioration and need to be extracted a few weeks to months later.

Eyes: Geriatric cats do not usually lose their eyesight, although it can become diminished, especially in dim lighting situations. However, the irises (the colored part of the eye that opens and closes) often begin to get a mottled appearance at about 15 years of age. This change alone does not affect vision.

Ears: The ears often are afflicted with two problems. Hearing loss and outright deafness occur in many cats over 16 years of age. It is permanent. Excessive wax production is the more common problem. Some older cats have very waxy ears that need periodic cleaning. A wax solvent may be used once weekly or as needed.

Arthritis/Musculoskeletal Problems: Arthritis occurs in the spine or legs of some geriatric cats. It causes them to become reluctant, or even unable, to jump on and off furniture; they may also be hesitant to climb stairs. They may be stiff when walking just after awakening, and/or at other times. Because simply moving around can be uncomfortable for these cats, the only outward symptom that an owner may observe is that the cat sleeps more, or does not seem to be moving around as much. We are limited in the drugs that can be used safely in arthritic cats, so a close examination and discussion of options are important. Food, water, and litter should be easily accessible for older cats, and especially when arthritis is present.

Certain diseases can also develop in senior cats with increasing frequency. The most common of these are diabetes, chronic kidney insufficiency, hyperthyroidism, high blood pressure, and cancer. Each will be described briefly.

Diabetes (more correctly called diabetes mellitus) is a disease caused by the failure of the pancreas to produce adequate insulin or by failure of the cells in the body to recognize and utilize the insulin (insulin resistance). Insulin is required to move blood sugar (glucose) from the blood into the cells. It results in excess urine production, increased thirst, weight loss, and a ravenous appetite. Although these signs should be present in all diabetic cats, some of them may be missed. This is especially a problem when cats go outside because they may eat, drink, and urinate outdoors. If you have several cats and they all eat and drink together, increased thirst or urine production in one cat may easily be missed. Longhaired cats, especially, can lose a substantial amount of weight without detection, so weight loss can also be overlooked. If you suspect that any of these signs are occurring, your cat needs a blood test to determine his or her blood glucose level. It is most accurate if your cat has not eaten for at least 6 hours. This is a treatable disease, though it often requires both a time and financial commitment on the part of the owner.

Chronic kidney insufficiency (or chronic kidney failure) is the result of many years of slow deterioration in kidney function. Kidney infections, certain toxins, and congenital diseases may be part of this deterioration process, but aging is the major factor. Something has to wear out first, and in many cats it is the kidneys. Cats with chronic kidney insufficiency actually produce an excessive amount of urine because the kidneys lose their ability to concentrate the urine by absorbing water back into the body through the kidneys. Thus the cats lose a lot of water via their urine, and their urine will appear less yellow or more “watery”. This results in increased thirst. Gradual weight loss is also common, and loss of appetite occurs as the disease progresses. It can be diagnosed with some simple blood and urine tests. It is manageable if treatment begins before the kidney insufficiency is advanced. While the process can be slowed and some of the symptoms can be alleviated with timely and appropriate care, the kidneys will continue to deteriorate, although this often occurs over the course of several years.

Hyperthyroidism is due to an enlargement of the thyroid gland. This gland controls the body’s rate of metabolism so metabolic functions are accelerated. The first sign is often weight loss followed by an increase in appetite as the cat tries to “catch up.” As the disease progresses (over several weeks to months), increased thirst and urination, vomiting, diarrhea, hyperactivity, and lack of sleep may also occur. It is diagnosed by feeling for thyroid gland enlargement and some simple blood tests. The good news is that 99% of the time, the enlargement is not due to a cancer; therefore, this is a very treatable, and curable, disease.

High blood pressure, more accurately called hypertension, is seen in some senior cats. Most of the time it is secondary to either chronic kidney insufficiency or hyperthyroidism. However, it appears that a few cats may have “essential” or “primary” hypertension. This means that there is not an underlying disease. Essential hypertension is common in humans. This disease is suspected in cats with the two underlying diseases and is diagnosed by measuring the cat’s blood pressure. Because the cat’s arteries are so small, a special instrument is required. The most common one used is based on the Doppler principle. Hypertension is very treatable.

Cancer is another common disease in senior cats. There are so many forms of cancer that it is impossible to list specific clinical signs. The signs will be determined by the parts of the body that are affected. Therefore, weight loss, anemia, lethargy, loss of appetite, vomiting, diarrhea, difficulty breathing and coughing are all possible. However, it is unlikely that all of those would occur in any one cat.

Detection of Geriatric Diseases
back to the top

Early detection is the key to successful treatment of all of these diseases. Many of them can be controlled or cured if diagnosed early enough. We recommend that a panel of tests for our senior patients be run at least annually. These tests begin with a thorough history of your cat’s past and present health. Next, a good physical examination is performed. Finally, we perform a blood and urine panel that includes specific tests for diabetes, chronic kidney failure, and hyperthyroidism. Blood pressure is determined. If any of these tests have questionable results, other tests are added including chest x-rays (radiographs), ultrasound studies, and possible biopsies of suspected abnormal organs. If you wish for your cat to have this Geriatric Panel of tests, please schedule it with one of our patient care coordinators.