Caring For Your Older Pet

Ron Hines DVM PhD 6/9/03 - second.chance2@verizon.net

Most pets and people are born with a healthy body. Their bodies begin with extra capacity to make up for the wear and tear of time. Some systems slow down while others loose their “ fine tuning”.

The kidneys, for example begin with four times as much filtering capacity, as your pet needs to cleanse its blood. So does the liver. But as time goes by organs slowly and steadily loose their ability to function.

This is called the aging process. Eventually one organ’s ability to function decreases past a critical point and we see a degenerative disease. It may be the kidneys, heart, lungs, joints or another organ system, which is the first to break down. All older pets and people have some partial organ loss.

There are treatments available for most of the problems of old age. We need to determine what they are in your pet and treat them to maximize the pet’s quality of life and life expectancy.

Our pets age more quickly than we do but not at the same rate. A three-year-old dog or cat approximates a twenty-seven year-old person. A six-year-old dog or cat approximates a forty-two year-old person. An eleven-year-old dog or cat approximates a sixty-year-old person and a twenty-year-old pet approximates a one hundred year old person.

Obesity

The most common problem I see in senior dogs and cats is obesity. They are just too plump. Feel your pet’s chest. Can you feel the ribs? Is his back nicely curved or flat like a table? Does he have a waist or a barrel-shaped belly?

Is he trim and active or lumbering around under signing under a heavy load of fat? There is a simple explanation for the second answers; they are receiving more food and less exercise than God designed them to. Welcome to the Club.

About four in ten dogs and cats that I see in my practice weigh too much. Food contains calories and when the number of calories eaten is greater than the calories used up during the day, the pet gains weight. Many clients tell me their fat dog or cat is a picky eater. Some do have sluggish thyroid glands but the majority do not.

There are two ways to control obesity in your pet. Give him only the amount of food his body needs or feed him a food, which is bulky, and less caloric. The second option is the one my clients usually choose.

Bulky, less caloric diets all have things in common. They are low in fat (3-4%) and are high in carbohydrate and roughage. Pets burn more calories digesting carbohydrates than fats so fewer calories are left at the end of the day. The extra fiber or roughage in the diet gives the pet the feeling of fullness without the calories.

Here are some things you can do:
1) Have blood work and a physical examination done on your pet to rule out medical causes for his obesity. Some middle-aged pets have medical conditions like hypothyroidism, adrenal problems or heart conditions that can mimic simple obesity.

2) Choose a diet low in calories but high in fiber. Some must be purchased through a veterinarian (Hill’s w/d, CNM’s OM diet, High Factor by IVD). These diets have recommended amounts to feed printed on the bag.

3) You can cook for your pet as well. Some recipes for weight-loss diets should be on this website.

4) Feed your pet several small meals instead of one large one or instead of food out throughout the day. Small meals burn more calories in digestion than do infrequent large meals.

5) Alternate small meals of your pet’s favorite dog food with meals of less caloric items such as cooked cabbage, carrots, string beans and peas. As with the commercially prepared weight loss diets, your pet will defecate more frequently and in greater volume. Do not worry about this.

6) Give your pet more exercise by taking walks, joining a dog club, fencing your yard, or babysitting a younger pet.

7) You can keep feeding the diet your pet is now on if you can bring yourself to feed only two-thirds of the amount you are presently feeding. Weigh your pet weekly. This should result in about a one percent weight loss per week.

8) Put your pet on a good multivitamin/multimineral supplement.

What we would like is a trim dog weighing no more than the average for its breed. Aim for a one percent weight loss each week. If weight loss is too rapid, good muscle will be lost with the fat. It is very psychologically hard on owners to do these things.

We love our pets and want to please them. And pets love to eat. Remember, pet snack treats are also highly fattening. Focus on the fact that the pet will be just as happy with a small bite of snack food as a large one.

I try not to send my clients on a guilt trip about their dog or cat’s weight. This is a very emotionally charged issue as it is in people and a lot of non-food factors are involved. I bring it up once or twice but never a forth or fifth time.

I eventually admit that no one has proven that fat pets live shorter lives than sleek pets and that they should enjoy each others company while they can rather than turning their home into a diet boot camp.

Do not feed semi-moist diets to cats. These diets contain propylene glycol, which, over time, can cause anemia and other problems in cats. I prefer to feed senior cats a dry “dental” diet low in ash.

Fat content of feline diets must be higher than the 3-4% used in low-cal dog foods. Healthy cats just need more fats in their diet than dogs do. Many older cats suffer from gum disease. This can lead to other health problems. There are diets such as Friskie’s Dental Formula that lessen the buildup of dental plaque. You can also extend the life of your cat’s teeth by brushing them with feline dentifrice.

2) Special Care

Older pets do not handle extremes or stress well. They are less tolerant of hot weather and cold. They need opportunities to relieve themselves more frequently and more rest periods during exercise. They are more dependent on you to compensate for poor vision, hearing and locomotion. Senior pets often do not groom as well as they did. Their skin and coats will benefit from medicated shampoos every week or two. Because they are less mobile, their toenails need more frequent clipping. This is also the reason old pets have more lick-associated skin inflammation. Obese pets often do not express their anal sacs normally and need assistance in this from you, your groomer or veterinarian.

3) Heart Lungs and Circulation

Old dogs commonly have heart problems. These problems are often diagnosed through a chest X-ray or ultrasound. Dogs do not get heart attacks like people do. Rather, their hearts enlarge and become inefficient in pumping blood throughout the body.

The most common heart problem in older dogs is failure of the mitral valve. This is a valve on the left side of the heart that prevents blood from backing up when the heart contracts. With time and aging, the lips of this valve thicken, preventing it from closing.

This leads to an enlarged, weakened heart (chronic passive congestion). Dogs and cats with this problem are put on diuretics (furosemide=Lasix) to remove excess fluid from the body, and drugs to increase heart strength (enalapril=Enacard=Vasotec or digoxin). They should also receive a potassium supplement.

Senior Doberman pinchers as well as other large breeds of dogs are quite susceptible to a type of heart failure known as acute cardiomyopathy. The cause of cardiomyopathy is unknown. Some veterinarians feel that a selenium supplement might protect against it.

3) Older cats, especially those that have overactive thyroid glands also may have high blood pressure. A cat’s normal blood pressure is about 150 mm of mercury (150 mm Hg). It is treated with diuretics and drugs called Beta-blockers and ACE inhibitors. Most of these cats also have kidney disease and compensate by drinking large amounts of water.

4) Bones and Joints

Arthritis is common in older dogs of the larger breeds. But it also occurs in cats and smaller dogs- particularly those that were bred for unusual body shapes such as Persian cats and dachshunds Joint problems often have their origins in puppyhood. I believe that arthritis later in the life of larger dogs is related to too rich and too abundant a diet. Too rich a diet causes the pup to grow too rapidly.

Its muscle mass soon outstrips the power of its joints and ligaments to function normally. Loose, arthritis-prone joints result. Some signs of joint pain in older dogs are slowness and reluctance to get up. Thick calluses develop on its elbows.

These dogs stand with their hind legs close together tucked under the body – that is too far forward. As they walk, their heads bob up and down. Their toenails are often overgrown. Their gait is stiff and there is a reduced range of motion of joints.

The large muscles of the thigh are often atrophied (shrunken). Osteoporosis or weak bones in general does not occur in animals as frequently as it does in human beings. The signs that I have related to you are also the signs one would see if the pet had age-related neurological disease of the spinal cord and disks.

X-rays help us determine which of these processes is occurring. Sluggish thyroid glands can also cause generalized weakness. Some signs that this is true arthritis in your pet are lameness that works out during the day, improves with rest, and has good and bad days.

One of the best ways to tell that this is truly arthritis is to give the dog (not cats) some non-steroidal anti-inflammatory medicine. Two marketed today in the United States are Rimadyl (carprofen) and Etogesis (etodolac).

These drugs will help arthritic pets but they are not effective against other causes of lameness. In Europe, ketoprofen and meloxicam work well and are also approved for use in dogs. Weight control in arthritic pets is very important.

Short (45 minute), moderate exertion exercise is quite helpful as are warm packs followed by flexing and extension of the joints to maintain range of motion. Two cartilage-sparing nutritional supplements also may help minimizing the pain associated with arthritis.

The first is a polysulfated glycosoaminoglycans called Cosequin. The second are purified glucosamine and chondrotin sulfate marked under various trade names. There will come a point in managing arthritis in old pets when cortisone-like drugs are required.

Your veterinarian will know when this time arrives. Cortisone blocks the pain and inflammation associated with arthritis but the drug has side effects such as fluid retention and liver enlargement, which must to be managed.

Never give human anti-arthritic drugs to cats. If you give over the counter human drugs such as ibuprofen or aspirin to dogs, remember that their dose is much lower than that for people.

Inflammation of the tendons connecting muscle to bone is quite common in older pets whose ligaments have lost their elasticity. This disease is called tenosynovitis. It often responds to local injections of a cortisone-like drug, methylprednisolone combined with cage rest.

5) Kidneys

The most common sign of kidney problems in all pets is an increase in the amount of water the pet drinks and a corresponding increase in urination. Kidneys are composed of tiny filters called glomeruli.

Some glomeruli cease working as time goes by and the body adjusts by drinking more water and making the ones that remain work all the harder. As the kidneys loose glomeruli they become smaller, firmer and lumpy. A veterinarian can judge how well the kidneys are by feeling them through the abdomen with his hands.

Weakened kidneys are the most common old age-related problem in cats and one of the most common in dogs. We ascertain the condition of the kidneys by running tests on the blood (B.U.N. & Creatinine) and urine (specific gravity).

There appears to be some degree of kidney insufficiency (damage) in all old pets. When B.U.N. and Creatinine and other waste products begin to rise in the blood the pet is said to be uremic. Uremia is a common problem in elderly pets.

Several things can be done to make your pet more comfortable: First, uremic pets benefit from lots and lots of water. We want them to drink and urinate as much as possible. Other signs of uremia are vomiting, weight loss and lethargy.

Sometimes we will give them subcutaneous fluids to help flush toxic waste material from their bloodstream. Most uremic pets are also anemic. This is because toxic waste in their blood stream depresses their bone marrow – the source of red blood cells and because their kidneys no longer produce enough erythropoietin, a hormone necessary to form red cells.

Administering anabolic steroids (stanazolol, nandrolone) to these pets helps them form new red blood cells and increases their energy level. A newer drug that counteracts the anemia of uremia is bioengineered human erythropoietin given twice a week. We also give them iron supplements. In cats, kidney disease and hyperthyroidism often exist together.

Elderly cats with kidney disease often also have high blood pressure. This is because the body tries to move as much blood through the remaining functional kidney as possible. Drugs called ACE inhibitors help lower blood pressure. The sooner kidney damage is detected and these therapies are begun, the longer the cat will live. I recommend that the urine from cats ten years and older be checked for specific gravity once or twice a year. Dilute urine from cats with kidney damage has a low specific gravity (under 1.015).

6) Skin

Older, less mobile pets are more likely to develop lick-associated sores on their skin. This is partially due to the skin not being as resilient as it was in youth but more to the immobility and boredom of elderly pets. Some times, the only way to keep them from licking an area is to bandage it.

Less mobile pets will also develop mats of hair along their backs as stiffness hampers their grooming. Older, heavy animals living on hard surfaces will develop inflamed calluses on their elbows. Sometimes the bursas associated with the elbow will enlarge also. The best treatment for this problem are mats or carpet flooring.

Older, fat pets often develop vaginitis or perianal (around the anus) inflammation due to extra folds of skin holding moisture and bacteria. These are best treated with topical antibiotic-cortisone sprays.

Another common age-associated change is extra black pigment between the hind legs. This is called acanthosis. It is due to chronic inflammation or low thyroid function. In itself it is inconsequential. Underlying inflammation usually responds to topical creams.

Older dogs often have a number of skin tumors. Fat pets are more susceptible to fatty tumors called lipomas. They have the consistency of a baggy filled with water. These tumors never move to internal body organs and only become a problem when their mechanical size makes the pet uncomfortable.

That is when I remove them. Another common tumor of old age is a button-shaped raised mass called a mast cell tumor. These tumors rarely move to internal body organs and are only locally invasive. I remove all skin tumors in high-risk, older pets under local anesthetic and tranquilization.

Skin tumors in older cats are much more serious than in dogs. A tumor called a fibrosarcoma will, on rare occasion, occur at the site of vaccination. We do not fully understand why vaccination would cause tumors but it appears that any injection – even water – through the skin of cats causes inflammation.

It may be that debris are carried under the skin when a large needle is used to administer these vaccines. Older cats are also quite susceptible to carcinomas of the skin. These are similar to the skin tumors that develop in people who receive too much sunshine. Both tumors need to be quickly removed along with a liberal section of adjoining tissue.

7) Eyes & Vision

Cataract formation in the lenses of the eye occurs steadily throughout the life of dogs and cats. Their age can be guessed quite accurately by the degree of cloudiness of the pet’s lenses. They occur more rapidly in pets with diabetis.

Heavily clouded lenses block vision in these pets. Objects appear quite hazy to them. Luckily, both dogs and cats rely on scent more than vision and pets with limited vision do quite well within the confines of their homes.

Even young dogs are quite nearsighted at best. That is why two dogs that approach each other must sniff their rears to determine weather to react in a friendly or aggressive manner.

Old cats also suffer from a decrease in blood supply to their retinas. When retinal vasculature (blood supply to the rear of the eye) decreases the cats loose vision. This and thyroid problems may be associated with feeding cats fish-based diets. It is possible that giving the cat and dogs vitamin E (200iu/day) as well as omega-3 fatty acids throughout its life will slow vision loss and other age-associated disease.

8) Dental Disease

Disease of the gums is much more common in pets than disease of the teeth such as cavities. A combination of serum oozing from inflamed gums, saliva and particles of food form plaque on your pet’s teeth that cause the gums to recede.

This is a spiraling phenomenon; as the gums recede they produce more plaque and the plaque causes more gum recession. Eventually the dentin of the roots of the teeth are exposed to the air and the teeth loosen in their sockets. Several things can be done to slow this process:

a) Feed a dry, dental diet to your pet. The crunchiness of kibble helps keep teeth clean
b) Brush your pet’s teeth daily to remove food particles and plaque
c) Have your pets teeth cleaned professionally with an ultrasonic scaler
d) Give dogs safe objects to gnaw on

One of the dangers of lack of dental care is infection spreading to other areas of the body. Bacteria that surrounding infected teeth continuously breaking off into the pet’s bloodstream and lodging in other organs such as the heart valves, kidneys and liver. I believe that much of the kidney disease we see in older cats is due to this process.

9) Weight Loss

Overactive thyroid glands are a common cause of chronic weight loss in older cats. A number of age-related disease can cause weight loss in dogs. These include chronic heart disease, liver and kidney failure. In each instance, the underlying problem needs to be treated. In my practice, I worry more about thin pets than I do about plump ones. Weight loss, once it occurs, is rarely replaced.

10) Delaying Aging

Please read my article, How and Why We and Our Pets Age, to understand more about the aging process.

11) Neurological and Behavioral Problems

Large dogs, having difficulty rising, unsteady gait and loss of housetraining, often suffer from ruptured intervertebral discs, cervical instability or spinal cord degeneration. Severe arthritis of the spine can also cause these problems. Unlike the lameness of inflamed joints and ligaments, these problems do not improve markedly on cortisone. Few treatments are successful.

Many veterinarians treat these conditions with supplements of selenium (200 micrograms/day), vitamin E (500-800iu/day) and 200-500 milligrams of vitamin C. Vitamin C is decreased if digestive disturbances occur.

Almost universal in very old dogs is some degree of a disease called Canine Cognitive Dysfunction Syndrome. This disease is the equivalent of Alzheimer’s disease in people. It begins with a pet that just seems less interested in what is going on in the family.

It does not greet family members when they return from work like it used to. It seems to sleep more than usual and is not as eager to go on walks. It may revert to old bad behaviors such as anxiety when left alone.

I may begin soiling in the house and walling about restlessly at night. There are non-neurological diseases that can mimic CCDS. Some of these are kidney failure (uremia), chronic liver disease (hepatic encephalopathy), low blood sugar (pancreatic tumor, insulinoma) and sluggish thyroid function (hypothyroidism).

Mechanical problems such as arthritis, heart problems, deafness and poor vision must also be ruled out. Owners of dogs with CCDS complain that their pet is dull and disinterested in activities going on around it.

It may bark at inanimate objects such as rocks or get confused when it is in corners, new environments or needs to open the door. The pet may vocalize or wander aimlessly. They often retain a good appetite. When pathologists examine the brains of these animals they find some of the same sort of changes found in Alzheimer’s disease (beta-amyloid plaques).

A bit more than half of dogs over 10 years of age show some of these signs. If the dog is fortunate enough to reach 16 or older virtually all dogs show some of these signs.

We use a drug called selegiline (Anipryl) to treat CCDS. This drug enhances the amount of chemicals within the brain that act as messengers between individual nerve cells.

We give selegiline at 0.25-0.5mg/pound body every day in the morning. It appears that dogs given this drug for the rest of their lives do live longer. It can also temporarily reverse some of the changes of CCDS. It can take up to sixty days to see an improvement. Some veterinarians also treat this condition with omega-3 fatty acid supplements.

12) Cushing’s Disease
Malfunction of a portion of the adrenal gland is quite common in older pets. The signs of this disease are due to the effects of cortisone on the body. The problem lies within the pituitary gland of the brain. Portions of the pituitary gland are responsible for producing a hormone (ACTH) that stimulates the adrenal glands to produce cortisone.

When too much ACTH is produced, the adrenal glands produce too much cortisone. Occasionally, a tumor of an adrenal gland is the source of the cortisone. Signs of this disease are excessive drinking (Polydipsia) and excessive urination (polyuria) as well as increased appetite and weight gain.

Skin and hair coat become thin and the dog may develop a pot belly. Muscle mass decreases and the dogs tire easily. As in CCDS the pet may loose enthusiasm for the things it once liked. The problem can be treated medically with a compound that reduces the production of cortisone (amitraz) or, in some cases, surgically.

13) Diabetes

Diabetes is common in middle aged and older pets. We see it commonly in cats that were overweight during a large portion of their lives. We also see it in plump dogs. Diabetes is due to a lack of the hormone insulin which is produced by the pancreas. A few cases respond to oral insulin-enhancing drugs but most require insulin injections. When treated, pets can survive many years with diabetes.

14) Thyroid Gland
Older pets, particularly dogs, often have sluggish thyroid glands. These thyroid glands no longer produce adequate amounts of a hormone called thyroxine. Usually, the problem is within the thyroid gland itself. It is probably a form of auto-immune disease in which the body attacks certain of its own tissues.

Thyroid hormone regulates the body’s metabolic rate. When not enough is produced several things happen. The animals tend to gain weight and the amount of fat (lipid) in their blood streams increase. In some pets, heart rate slows, body temperature declines and hair ceases to regrow normally.

Other pets will show muscle weakness. Cats often are lethargic, have poor appetites, slow heart rates, elevated cholesterol, low body temperature and skin and coat abnormalities. This disease can be diagnosed through a simple blood test. Low thyroid hormone can also be secondary to a number of other diseases.

Older cats commonly have the reverse of this condition, that is, an overactive thyroid gland. This problem is called hyperthyroidism. These cats are thin. They have a fast heart beat and often vomit. They tend to drink a lot.

In these cats the level of thyroid hormone is high. Hyperthyroidism in cats goes hand in hand with kidney problems. Often the signs of kidney damage are masked by the overactive thyroid and it is only when the cat has been on thyroid medication (Tapazol, methimazole) that the kidney problem becomes apparent.

15) Liver
Apparently healthy older pets commonly have elevated liver enzymes, especially Alkaline Phosphatase (ALP). In some cases this is due to drugs the dog received such as prednisolone, ibuprofen or Phenobarbital. In others, two types of chronic hepatitis, hepatic nodular hyperplasia or vacuolar hepatopathy are to blame. These diseases are poorly understood. Neither of these conditions is life threatening and they both can be managed nutritionally by using the same low protein diets recommended for kidney disease.