Caring For Your Older Dog And Cat
Ron Hines DVM PhD
Most pets and people are born with healthy bodies. Nature gave these bodies extra capacity than what they needed to make up for the wear and tear of time. In most organ systems, the amount of organ capacity necessary for normal life is less than a quarter of the organ’s ability in youth. (ref1, ref2)
Systems slow down or loose too much of their “ fine tuning”. Your pet’s kidneys, for example, begin with four times as much filtering capacity, as your pet needs to cleanse its blood. The liver has even greater reserves. (ref) But as time goes by, cell death and genetic errors causes these organs to loose their ability to perform their functions. This is what the aging process actually is. When your veterinarian runs blood tests on your older pet, the results and values will not be quite the same as they were when it was younger.
Eventually one of your pet’s organs will loose its ability to function and past a critical point. Then you will see the beginning symptoms of a degenerative disease. It may be the kidneys, heart, lungs, joints or another organ system, which is the first to break down. Or it may be the accumulation of enough genetic errors or chronic irritation to cause a cancer to appear.
We all have some partial organ loss. There are treatments available for many of the problems of old age to correct or at least slow down the process but, although we dream of cure, there are no cures. Veterinarians can only determine what the most important health issues are in your pet and treat them to maximize your pet’s quality of life and life expectancy.
Our pets age more quickly than we do but not at quite the same relative rate. A 3 year-old dog or cat approximates a twenty-seven year-old person. A 6 year-old dog or cat approximates a 42 year-old person. An 11 year-old dog or cat approximates a 60 year-old person and a 20 year-old pet approximates a 100 year old person.
Certain breeds seem to age faster than others and larger dog breeds often age faster than smaller breeds.
Chronic stress and deprivation age pets faster. Mature, shelter-obtained pets, have been through a lot that may age them prematurely.
Obesity
You can read an article specifically about obesity in dogs and cats here. This is one of the most common problem I see in senior dogs and cats. Many are just too plump. Feel your pet’s chest. Can you feel the ribs? Is its back nicely curved or flat like a table? Does it have a waist or a barrel-shaped belly? Is it trim and active or lumbering around and sighing under a heavy load of fat?
If any of the answers are yes, there is a simple explanation ; 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 more than they should.
>When the number of calories your pet eats is greater than the calories it uses up during the day, your pet gains weight. Despite that, many clients tell me their fat dog or cat is a picky eater. A few do have have sluggish thyroid glands and slow metabolism, but the majority are just consuming too many calories.
But never assume that every dog or cat that is overly round or pear-shaped is fat. You need to have your veterinarian eliminate the possibility of fluid retention (circulatory problems), liver enlargement or abdominal cancer as a cause for the weight gain.
There are three ways to control obesity in your pet. Give it only the amount of food his body needs. Feed it a food, which is bulky, and less caloric. Or see to it that your pet gets more exercise. 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%), moderate in carbohydrate and high in roughage (fiber). Many vets think that pets burn more calories digesting proteins than digesting carbohydrates or fats so fewer calories are left at the end of the day. So a higher protein diet might even help with weight loss. Other vets fear that increased protein levels in elderly pets puts undo stress on their kidneys. We really do not know. Extra fiber or roughage in the diet gives the pet the feeling of fullness without the unnecessary calories.
What Are Some Of The Things I Can Do ?
Have blood work and a physical examination done on your pet to rule out medical causes of obesity. Some middle-aged pets (particularly dogs) have medical conditions such as hypothyroidism, adrenal problems or heart conditions that can mimic simple obesity. Veterinarians have at their disposal, central laboratories that perform “geriatric profiles” that are designed to detect the common health hazards of old age.
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, etc). These diets have a recommended amount to feed printed on the bag.
Alternatively (and probably a better choice), bulk your dog’s current diet with low-cal items such as cooked carrots, boiled stir-fry blend, and other produce. The added fiber will often cause loose stools for a period of time. When that occurs, cook the vegetables longer, reduce the amount you feed, grind them up finer or try other produce. The fiber in commercial low-cal dogs and cat foods is usually sugar beet pulp. Manufactures us that because it is inexpensive, readily available and contains both soluble and insoluble fiber. Feed stores sell it in sacs to feed to horses – but I would stick to adding fibrous vegetables.
You can cook a complete diet for your pet as well. Some weight-loss diet recipes are on this website. You can read about them here.
Feed your pet several small meals instead of one large one or instead of food left out all day. Small meals burn more calories in digestion than do infrequent large meals.
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 that.
Give your pet more exercise by taking walks, joining a dog club, fencing your yard, or babysitting a younger pet.
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. There is no place for crash dieting when it comes to our pets.
During a serious diet, put your pet on a good multivitamin – multi mineral supplement such as senior Centrum®. Give only a portion of the crushed tablet that is appropriate for the weight of your pet. Most human-sized vitamin tablets use 150 pounds as the standard adult human weight.
Your goal should be to to make your pet a trim dog or cat, weighing no more than the average for its breed. Aim for a slow but steady (1%) weight loss each week. If weight loss is too rapid, good muscle will be lost along with the fat.
It is psychologically hard for many owners to do the things I recommend. We all love our pets and want to please them. My Labrador, Maxx, is on a perpetual diet and he is perpetually hopeful that whatever I feed him won’t be the last meal of the day. Pets love to eat – it is one of their greatest joys in life. But the rewards in added mobility and lifespan are well worth moderation – fat in itself, is known to decrease lifespan (ref) and caloric restriction increases it in every species that has ever been studied. (ref)
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. Rawhide chews provide endless hours of satiation for dogs and are a much better alternative to edible caloric treats (Milkbones®, etc).
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, just like 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. Eventually I admit that a happy fat pet is better than a trim, sad one and that they should enjoy each others company while they can rather than turning their home into a diet boot camp.
Cats do not do as well on reduced fat diets as dog. While dogs do well on a diet as low as 8-10% fat, cats do not thrive on diets much below 15% fat (on a dry weight basis).
Many older cats and dogs suffer from gum disease. While it is more of a problem in toy and small breed dogs, it occurs fairly uniformly in all aged cat. There are dry diets that are formulated to help keep plaque down and prevent gum disease. But I currently feel that the extra water in canned and fresh homemade soft diets is more important in preserving kidney health. Ideally, keep your pets teeth clean by beginning to brush them early in life.
Special Care
Older pets do not handle extremes, changes 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 their poor vision, hearing loss and limited locomotion. All these things need to be taken into consideration when planning a daily schedule for elderly pets.
Senior dogs and cats rarely groom as well as they once did. Their skin and coats will benefit from medicated, moisturizing shampoos every week or two. Because they are less mobile, their toenails need more frequent clipping.
Older pets have more lick-associated skin inflammation because self-grooming is less of an exertion than moving about. Elderly dogs, particularly large ones on hard floors all develop hair loss and calluses on their elbows. They are of no consequences unless they become raw and infected. The best treatment is weight reduction in overweight pets, soft carpeted areas and extra padding in their bed or sleeping area. Infected elbows often need bandaging to heal as less active, older pets spend the day licking them. Bitters sprays are ineffective. If you soften and protect them with creams, be sure the cream contains no cortisone. Occasionally, these elbows will form a serum pocket (hygroma) which will need veterinary attention. (ref)
Obese or older pets may not express their anal sacs normally and need assistance in this from you. Your veterinarian or groomer can instruct you in the method.
Both chronically loose stools and chronically hard stools lead to anal sac problems. Feeding table scraps is another cause of this problem. It can almost always be cured through diet. Read about anal sac problems here.
Heart Lungs And Circulation
Many older dogs and some older cats develop heart problems. Pets usually arrive at the vets because of weakness, coughing or a swollen tummy (abdomen). Your vet will confirm the diagnosis with a stethoscope and chest X-ray or ultrasound.
Dogs do not get heart attacks like people do. Instead, their hearts enlarge and become inefficient at pumping blood throughout the body. The most common heart problem in older dogs is failure of the mitral valve to completely close. This valve, on the left side of your pet’s heart, prevents blood from backing up when its heart contracts (beats). With time and aging, the lips (leaves) of this valve thicken, preventing it from fully 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 decrease the work load on their heart ( enalapril =Enacard®=Vasotec® or similar medications ) and medications to give the heart added strength in its contractions (pimobendan = Vetmedin®). Some will need potassium supplements and other supportive medications. Read about the problem in dogs here.
Senior Doberman pinchers and certain other large breeds of dogs are quite susceptible to a type of heart failure known as acute cardiomyopathy. The cause of cardiomyopathy is unknown. Read about that here.
Older cats, especially those that have overactive thyroid glands (hyperthyroidism) also may have high blood pressure. You can read about hyperthyroidism in cats here. A cat’s normal blood pressure is about 150 mm of mercury . When its systolic blood pressure is above 159, (ref), most veterinarians begin treating the problem in dogs with drugs called ACE inhibitors inhibitors such as enalapril or benazepril ; and in cats with Calcium channel blockers (amlodipine) and sometimes diuretics as well. You can read about the problem here.
Many cats affected with high blood pressure also have kidney disease and compensate by drinking large amounts of water. High blood pressure does not to be nearly as common a problem in elderly dogs. Your veterinarian might even recommend a low-salt diet for your pet. With time, untreated high blood pressure often leads to vision problems.
Bones And Joints
Arthritis is common in the larger breeds of older dogs. But it also occurs in cats and smaller dogs- particularly dogs that were bred for unusual body shapes such as dachshunds, bulldogs and Asiatic terriers types. Persian cats seem more susceptible to arthritis of the hip.
Joint problems late in life probably have their origins in puppy and kittenhood. Overly fast growth do too too rich and abundant a diet when these pets are young places stresses on bone and cartilage that often do not appear until the pet is much older. When pups grow too rapidly, their muscle mass soon outstrips the power of their joints and ligaments to function normally. Loose, arthritis-prone joints result. But in other pets, the tendency to arthritis seems to be primarily genetic.
Some signs of joint pain in older dogs and cats are slowness and reluctance to get up. Thick calluses develop on the elbows of heavy dogs.
They stand with their hind legs close together tucked under the body and 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 their thigh are often atrophied (shrunken).
Osteoporosis or weak calcium-deficient bones does not occur in animals as frequently as it does in human beings. It is exceptionally rare. 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 are the best way to determine which of these processes is responsible for your pets pain.
Sluggish thyroid glands (hypothyroidism) can also cause generalized weakness. You can read about hypothyroidism in dogs here.
Some signs that your pet has true arthritis are lameness that works out during the day, improving with rest, and lameness that has good and bad days. If x-rays leave uncertainties whether your dog’s sluggishness is due to arthritis and blood tests are normal, one of the best ways to tell that this is true arthritis is to put the the dog (never cats) on a short course of non-steroidal anti-inflammatory medicine. Common ones marketed in the US today are Rimadyl® (carprofen) Etogesic® (etodolac) and meloxicam. They can all cause problems and pets on these medications need to be carefully monitored.
Do not give these medications casually, they all have potential serious side effects. You need to decide if your pet is in enough pain that these potential side effects are really worth chancing.
These drugs do help many arthritic dogs, but they are very dangerous to use in cats. None should be given to dogs either without close veterinary supervision.
Weight control in arthritic pets is very important. But short, moderate-exertion, exercise is quite helpful as are warm packs followed by flexing and extension of the joints to maintain range of motion. Swimming, heated baths and whirlpool tubs work wonders as well. Arthritic cats, especially, appreciate an electrically warmed bed.
Two “cartilage-sparing” nutritional supplements are sold to help minimizing the pain associated with arthritis. The first the oral purified glucosamine and chondrotin sulfate products (like Cosequin® ) and the second, an injectable form of polysulfated glycosaminoglycan (PSGAG) called Adequan. Unfortunately, the latest studies on the use of cosequin-like medications in humans found them ineffective. (ref). Whether Adequan is any better remains to be seen. But there is certainly no harm in having your pet receive Adequan injections or Cosequin for a trial period to look for any positive effect.
There often comes a point in managing arthritis in fading old pets when cortisone-like drugs are required. Your veterinarian (and you) will know when this time arrives. Cortisone blocks the pain and inflammation associated with arthritis but the drug has major side effects that include fluid retention and liver enlargement, which must to be managed. If the DEA did not harass American veterinarians so much when we prescribed long term, pain relieving narcotics such as fentanyl patches, I would suggest you use them before resorting to steroids.
Never give human anti-arthritic drugs, aspirin or Tylenol to cats. If you give over the counter human drugs such as ibuprofen or aspirin to dogs (which I do not recommend), remember that their dose is much lower than the dose 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 acetate) combined with cage rest.
Kidneys
The most common sign of kidney problems in all pets is an increase in the amount of water they drinks and a corresponding increase in the amount they urinate. Kidneys are composed of tiny filters called glomeruli. Some glomeruli cease working as time goes by and the pet’s body adjusts by drinking more water and making the glomeruli that still remain, work all the harder. As the kidneys loose glomeruli they become smaller, firmer, and lumpier (scarred). Your veterinarian can judge how well the kidneys are by feeling them through the abdomen with his/her 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 your pet’s kidneys by running tests on the blood (BUN & Creatinine) and urine (specific gravity, protein content, etc.). If you would like to find the normal levels in your pet, go here.
There appears to be some degree of kidney insufficiency (damage) in most old pets. When BUN. , Creatinine and other waste products begin to rise in the blood your pet is said to be uremic. Uremia is a common problem in elderly pets. You can read about it here.
Several things can be done to make your pet in kidney failure feel more comfortable:
First, uremic pets benefit from lots and lots of water. We want them to drink and urinate as much as possible because we know this helps preserve its remaining kidney function that they have. (ref) Sometimes we will even give these pets subcutaneous fluids to help flush toxic waste material from their bodies and we may teach you how to do that at home.
Other signs of uremia are vomiting, weight loss and lethargy. Your veterinarian can prescribe medications to calm your pet’s stomach and intestines and dispense or suggest high caloric products to slow or reverse its weight loss.
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 blood cells.
Administering anabolic steroids (stanazolol, nandrolone) to these pets sometimes seemed to help them form new red blood cells and increases their energy level. These medications have fallen out of favor for that use – although it is still considered effective in combating anemia and uremic weight loss in human medicine. (ref1, ref2). One must be particularly cautious about giving anabolic steroids of any kind to cats – give them only when there are no other options available.
Many pets in uremic failure (failing kidneys) develop dangerous changes in their blood calcium and phosphorus levels. The condition is called secondary hyperparathyroidism and it is due to changes that occur in the small parathyroid gland in your pet’s neck. These pets may need a low-phosphorus diet, medications called phosphate binding agents and, perhaps, a special form of vitamin D called calcitriol. Read more about this problem and the treatments for uremia here.
There were initial high hopes for a newer drug that counteracts some anemias – bio engineered human erythropoietin. It can have remarkable effects, initially in uremic pets, but with time, it looses its effectiveness and may even stimulate antibodies that make the problem worse. (ref)
Elderly cats with kidney disease often also have high blood pressure (hypertension). This is because their inability to produce enough aldosterone, a compound that regulates blood pressure. 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). Protein leakage into the urine is another warning of kidney damage. A rather recent test detects it in very small amounts and may be useful as an early warning that the pet’s kidneys are struggling to keep up with the body’s needs (microalbuminuria test).
There was a time that veterinarians recommended low protein diets for pets with poor kidney function. However, controlled experiments showed that lowering dietary protein too much, actually did more harm than good. (ref)
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 their youth, but more to the immobility (difficulty getting around) 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 ability. Older, heavy animals living on hard surfaces develop inflamed calluses on their elbows. They all need a hand from you in combing out these mats. Don’t pull them off, carefully and gently cut them free.
Fat , older pets sometimes develop vaginitis or perianal (around the anus) inflammation due to extra folds of skin that hold moisture and bacteria in that area. This is a female problem, and it is worse in pets that were spayed too young. (ref) These problems are best treated with topical antibiotic-cortisone cream or spray. Any product approved for diaper rash in babies works well in the perianal area if the pets do not lick it off. But serious vaginitis is best treated with an course of oral antibiotics.
Another common, age-associated, change in pets is extra black pigment between their hind legs. This is called acanthosis (A. nigra). It is primarily a problem in dogs. It is due to chronic inflammation produced by folds or scabby skin, low thyroid function or other hormonal imbalances. When standard test do not detect the cause, the University of Tennessee will screen your pet for hormonal imbalances that might be involved. Acanthosis, in itself, is inconsequential. The underlying inflammation usually responds to topical creams. I see the problem, most frequently in old dachshunds.
Most older dogs often have a number smaller tumors scattered throughout their body. Most cause no harm. Fat pets are more susceptible to one of these benign tumors, a fatty tumor called a lipoma. 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.
Mammary (breast) tumors are also a problem in older female dogs that remained unspayed or were spayed late in life. Most do not need to be removed unless or until they become bothersome to the pet because they rarely spread. This is not the case in cats, visible and internal tumors in cats are often highly malignant and need to be immediately treated or removed.
Another common tumor of old age is the 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. It is never wise to give general anesthetics to debilitated oldsters if one can avoid it.
In cats, a tumor called a fibrosarcoma will, on rare occasion, occur at the site of vaccinations. We do not fully understand why vaccinations cause tumors but it appears that in cats, 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, it may be that components (adjuvants) in the vaccines are the source of the problem – we just do not know yet. Merial markets a line of vaccines and a devise that allows vaccines to be sprayed through unbroken skin.(ref) That is probably the best way to administer vaccines to cats of any age. However, there is almost never a valid reason to vaccinate older, house-confined cats (or dogs) (ref) You can read more about fibrosarcomas in cats here.
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 but they are rarely black. Both tumors need to be quickly removed along with a very liberal (large) section of adjoining skin and tissue.
Eyes And Vision
Cataract formation in the lenses of the eye occurs steadily throughout the life of dogs and cats. ( veterinary ophthalmologist will tell you that this is actually a problem called lenticular sclerosis and not true cataracts, but most people still call them cataracts). The age of a pet can be guessed quite accurately by the degree of cloudiness of its lenses. Cataracts occur more rapidly in pets with diabetes. Very heavily clouded lenses block your pet’s vision. When place your pet in a dark room and shine a light into its eyes, both pupils should contract fully and in equal amounts. I become most worried when their is a marked difference in the response of one eye over the other.
When the cataracts are serious (mature cataract) , objects will appear quite hazy to them. Luckily, both dogs and cats rely on scent more than vision and pets with limited vision do very well within the confines of their homes. Even young dogs are quite nearsighted at best. That is why two dogs that approach each other sniff their rears to determine weather to react in a friendly or aggressive manner.
Old cats can 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, and hypertension may be associated with feeding cats canned, fish-based diets. (ref)
It is just possible that giving the cat and dogs vitamin E as well as omega-3 fatty acids and other antioxidants throughout their lives will slow vision loss and other age-associated disease.
Dental Disease
Disease of the gums is 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 its gums to recede. This is a spiraling phenomenon (process) ; as the gums recede, they produce more plaque and the plaque causes more gum recession. Eventually the dentin covering the roots of the teeth are exposed and the teeth become loose in their sockets. Several things can be done to slow this process:
Feed chew-toys to your pet. The crunchiness of occasional kibble also helps keep teeth clean. Just do not sacrifice the good hydration of wet foods for clean teeth.
Brush your pet’s teeth daily to remove food particles and plaque (I prefer a finger cot to a toothbrush).
Have your pets teeth cleaned professionally. If a pet needs to have its teeth cleaned more than once a year, or if the strong odor of gum infection returns a few months after the cleaning – the teeth causing the problem need to be removed to preserve your pets general health (pets with few teeth or no teeth live very contented, pain-free, lives).
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 lodge in other organs such as the heart valves, kidneys, and liver. I believe that some of the heart and kidney disease we see in older pets is due to this process. A similar situation occurs in humans. (ref)
Weight Loss
Overactive thyroid glands (hyperthyroidism) are a common cause of weight loss in older cats. A number of other age-related disease can cause weight loss in dogs and cats. 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 very challenging to reverse.
Delaying Premature Aging In Your Pet
You can read about how and why we and our pets age here, to understand more about the aging process. So far, the only procedures that show promise are caloric restriction (ref) and a medications such as rapamycin and resveratrol. (ref) Perhaps in the future we will find the fountain of youth – but don’t believe folks who tell you they’ve already located it.
Neurological And Behavioral Problems
Large dogs, having difficulty rising, unsteady gait and loss of house training, often suffer from age-related, spinal cord degeneration. In some of these cases, a ruptured inter vertebral disc, cervical (neck) spine instability or severe arthritis of the spine is found to be the cause, but often no cause, other than time and aging, can be found.
Unlike the lameness and pain of inflamed joints and ligaments, these problems do not often improve on cortisone or anti-inflammatory drugs.
This problem of just not being able to get up is the number one cause that clients bring there pets to me to be put down. Your pet will tell you when that time comes – listen to what it tells you, not to what your veterinarian or kids tell you.
Almost universal in very old dogs is some degree of a disease called Canine Cognitive Dysfunction Syndrome. (CCDS) 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 forgets the tricks you taught it when it was young, 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. You can read more about CCDS here.
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 like 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. It appears that dogs given this drug for the rest of their lives do live a bit longer. It can temporarily reverse some of the signs of CCDS but not the brain damage of CCDS. It might take up to sixty days to see an improvement. (Some veterinarians also treat this condition with omega-3 fatty acid supplements).
Cushing’s Disease
You can read an article specifically on Cushing’s Disease here. Malfunction of the outer portion of the adrenal glands is quite common in older pets. The signs of this disease are due to the effects of too much cortisone on the body. The underlying problem usually lies within the pituitary gland of the brain. Portions of the pituitary gland are responsible for producing a hormone (ACTH) that stimulates the pet’s 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 compounds that reduces the production of cortisone (mitotane, trilostane) or, in some cases, surgically. Read more about the problem here. It is much less common a problem in cats.
Diabetes
Diabetes is common in middle aged and older pets. You can read about the problem in cats here and dogs here. 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 or defect in the utilization of the hormone, insulin, which is produced by the pancreas. A few cases respond to oral insulin-enhancing drugs, but most require insulin injections. With treatment and diet change, pets can survive many years with diabetes.
Thyroid Gland Problems
Older pets, particularly dogs, often have sluggish thyroid glands (hypothyroidism) while in older cats, over-active thyroid glands (hyperthyroidism) are the more common problem.
In hypothyroidism, the thyroid glands no longer produce adequate amounts of a hormone called thyroxin. Usually, the problem is within the thyroid gland itself. It is probably a form of autoimmune disease in which the body attacks certain of its own tissues. Thyroid hormone regulates the body’s metabolic rate – the rate at which it burns energy. When not enough is produced several things happen: The pet tends to gain weight and the amount of fat (lipids = cholesterol & triglycerides) in their blood streams increase. In some pets, heart rate slows, body temperature declines and hair ceases to re grow normally. Other pets will show muscle weakness. Cats do occasionally develop sluggish thyroids. When they do, they are often lethargic, develop slow heart rates, elevated cholesterol, low body temperature and skin and coat abnormalities. This disease can usually be diagnosed through a simple blood test (free T-4). Low thyroid hormone levels do not always indicate hypothyroidism, it can also occur secondary to a number of other diseases and return to normal when those health issues are corrected. Read more about hypothyroidism here.
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 often have a fast heart beat and elevated blood pressure. Many of these cats vomit or gag frequently and many are hyperactive. They tend to drink a lot. In these cats the level of thyroid hormone is too 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 or has received radioactive iodine treatment that the kidney problem becomes apparent. Read more about hyperthyroidism in cats here.
Your Pet’s Liver
Apparently healthy older pets commonly have elevated liver enzymes, especially alkaline phosphatase (Alk Phos, ALP). In some cases this is due to drugs the dog received such as prednisolone, or phenobarbital. In other pets, two types of chronic hepatitis, hepatic nodular hyperplasia or vacuolar hepatopathy are sometimes to blame. These diseases are poorly understood. Both can be managed nutritionally by using the same low protein diets recommended for kidney disease. When your veterinarian suspects liver disease in your pet, the only test that will help design a treatment plan is a liver biopsy.