Pets are living longer. Because of advances in nutrition and prevention care, an 11-year-old cat may look and act as energetic as a cat half their age. This doesn't mean that his body is not aging. In fact, an 11-year-old cat is the equivalent to a 60-year-old person.

Age brings along a series of diseases, most of them preventable or at least treatable if discovered in the early stages. For animals older than eight, a complete yearly exam is key. For pets over 10 or those at risk, exams should be conducted every six months and should include an ultrasound and EKG.

The most common diseases to affect older pets, in no particular order, are:

Obesity

What Is It: Obesity is a widespread problem among senior cats and dogs. As pets age, they become more sedentary and do not burn as many calories as they used to do when they were younger. Still, many keep eating the same amount of food, resulting in obesity, which in turn can lead to a series of medical conditions, from diabetes to heart disease.

Symptoms: If you cannot feel the ribs of your pet, he or she is probably overweight. Rounded backs in cats are also a sign of extra weight.

Treatment: Low-calorie, low-fat diets are recommended in most cases. The best ones are only available through a veterinarian, such as Hill’s w/d and High Factor (by IVD). In animals with severe obesity, a special prescription diet can be administered for a while, until the animal goes down to a more normal weight. These diets are usually high in fiber, which helps with digestion and makes the animal feel full on less food. Small, frequent meals throughout the day are better than one or two large meals.

Heart Disease & Circulation Problems

What Is It: Although pets cannot get heart attacks, they can suffer a series of other equally serious heart conditions. Chronic valvular heart disease (VHD) is the most common heart condition in older dogs. In VHD, the heart valves thicken, making it difficult for the heart to pump blood effectively, and causing accumulation of fluid in the lungs. Of the many types of heart disease to affect older pets, some are quite manageable if diagnosed early and treated with aggressive drugs and dietary changes, while others are very hard to treat. Early detection of heart disease is crucial to save your pet's life.

High blood pressure is also common in older pets (especially cats) and it's often associated with kidney disease.

Symptoms: Weakness, loss of appetite, coughing or labored breathing, syncope (fainting), enlarged abdomen, tachycardia. Sometimes a venous pulse becomes palpable. Symptoms in cats usually do not show until the disease is well advanced. EKG's, x-rays, and ultrasounds done as part of routine care can show heart disease signs, such as enlargement of the chambers, thickening of the walls, or stretched muscles.

Treatment: Diuretics are used to remove pooled fluid from the body, a common occurrence when the heart cannot pump efficiently. Other drugs are prescribed to increase heart strength and/or contractility, and reestablish normal heart rhythm. Beta blockers and ACE inhibitors are also used. A diet low in sodium can help considerably.

Bones and Joints

What Is It: There are several types of arthritis that can affect older pets. Most of them are unique to dogs of the larger breeds. The most common type of arthritis is degenerative joint disease, where parts of the joint are destroyed and cannot be repaired.

Symptoms: Difficulty getting up, stiffness, restlessness when trying to settle down to sleep, frequent slips and falls, shrunken thigh muscles. The animal usually has good and bad days.

Treatment: Non-steroidal anti-inflammatory drugs, such as Rimadyl and Etogesis, are available to treat arthritis. Weight control and daily exercise are important, as they help pets move better and maintain joint flexibility. Glucosamine supplements have become a popular addition to traditional treatment. In advanced cases, cortisone-like drugs may be required, which cause serious side effects that have to be monitored closely.

Kidney Disease

What Is It: As kidneys become damaged, they lose their ability to filter toxins, and waste products accumulate in the blood, causing intoxication. All senior pets have some degree of kidney insufficiency. In serious conditions, such as Chronic Renal Failure (CRF), the kidneys lose over 90 percent of their filtering abilities. CRF is a terminal illness affecting almost 25 percent of older pets. If discovered in the early stages, it can be managed with somehow satisfactory results.

Symptoms: Increase in drinking and urination, weight loss, lethargy, vomiting

Treatment: Subcutaneous fluids (IV in acute cases) are a common therapy to keep the animals hydrated and help their bodies flush accumulated toxins. Antibiotics are used regularly, as infections and bacteria of the urinary track are common in pets with kidney disease. Iron supplements are used in cases of accompanying anemia. Kidney disease causes the body to work harder, raising blood pressure. Many cats require ACE inhibitors to help lower their blood pressure.

Skin

What Is It: Sores are common in pets that have lost some mobility and may be a sign of arthritis, where the pet refuses to move due to pain. Skin tumors such as malignant melanoma are rare in dogs but they do occur; they are more frequent in cats. Tumors more frequently show up as lumps that are not noticeable until they're large enough to be visible. Lipomas are a common type of non-invasive tumor among overweight pets.

Symptoms: Sores, unkempt coat, lumps or abnormalities in the skin.

Treatment: Padded mats or orthopedic beds are recommended for older pets to ease any pain and discomfort. In the case of a lump, a biopsy and fine-needle aspiration is always recommended to rule out mast cell tumors, the deadliest skin cancer in dogs. Surgery may be necessary to remove the tumor.

Cataracts

What Is It: A cataract is any opacity which develops in the crystalline lens of the eye or in its envelope. The opacity ranges from small marks that barely interfere with vision to deeply clouded lenses that cause blindness. High blood pressure, diabetes, and eye inflammation or trauma can cause cataracts and blindness at any age; otherwise, normal aging can also result in a gradual loss of vision. Cataracts are inherited. Tear production also diminishes with age, leading to other vision problems, such as dry eye (keratoconjunctivitis sicca).

Symptoms: Blue-gray tinted eye lens

Treatment: A veterinary ophthalmologist can surgically remove most cataracts with a success rate of 90 percent in dogs (somewhat less in cats). Intraocular lenses can now be implanted to help with vision focus and acuity. Oral and localized medication is compulsory after surgery to prevent infections. As cataracts are closely connected to diabetes, treating this disease will reduce the chances of your pet developing cataracts in the first place.

Dental Disease

What Is It: Almost 90 percent of pets over five years old have some degree of dental disease. Animals do not commonly get cavities, but are prone to gum disease and mouth infections. When tartar buildup becomes severe, it can irritate and retract the gum line, eventually leading to tooth loss. Severe dental disease can also leak bacteria into the bloodstream, which in turn can lead to serious kidney, liver, and heart disease.

Symptoms: Excessive tartar buildup, bad breath (halitosis), gum inflammation, dark or discolored teeth, drooling, difficulty eating.

Treatment: Feeding a dry diet will help keep the teeth clean. Chew toys and dental treats can reduce plaque. If you start at a young age, most pets can become accustomed to daily brushing. For advanced cases, veterinarians can provide scaling, an in-depth cleaning process that removes tartar from below the gum line. Root canals and teeth removal may become necessary for animals in pain.

Cognitive Dysfunction Syndrome

What Is It: CCDS is a disease that affects older dogs, causing chemical changes in the brain. It is the equivalent of Alzheimer’s disease or senility in people. Symptoms are usually detected by owners, who notice strange behavior for no apparent reason. Dogs affected by CCDS show no physical signs of disease and continue to eat normally.

Symptoms: Change in activity level or sleeping patterns, confusion and disorientation, increased whining, isolation, anxiety attacks, decreased interaction with family members, forgetfulness. Dogs sometimes get "stuck" in corners or wander aimlessly. Housetrained pets have frequent "accidents." These and other changes in behavior are not normal and are not part of getting older. They should be reported to your veterinarian.

Treatment: A drug called selegiline (Anipryl) is commonly used to treat CCDS.

Cushing’s Disease

What Is It: An endocrine disorder caused by excessive levels of the hormone cortisol. A tumor in an adrenal gland can be the cause of the overproduction of cortisone, but normally it is simply due to a malfunction or lesion of the glands. It is more common in certain breeds, such as Beagles, Boston Terriers, and Dachshunds.

Symptoms: Excessive drinking and appetite, increased urination, weakness in the back legs, lethargy, thinning hair, skin hyper pigmentation, panting, frequent urinary tract infections, distended abdomen, obesity.

Treatment: The drug Lysodren is commonly prescribed to treat Cushing’s Disease. After several large daily doses for a period of a week, a maintenance dosage is established, which should be kept for the duration of the animal's life.

Diabetes

What Is It: The same as with humans, diabetes mellitus (DM) is a medical disorder characterized by varying or persistent hyperglycemia (elevated blood sugar levels). Miniature breed dogs and overweight pets are more susceptible, but animals can also develop diabetes after treatment with steroids or reproductive hormones, pancreatitis, or infectious viral diseases. Type I diabetes is always insulin dependent (IDDM), while Type II may or may not require insulin injections (NIDDM). Most diabetic dogs have IDDM.

Symptoms: Excessive urination, excessive appetite and thirst, weight loss, lethargy. Depression and vomiting are seen as the disease progresses. Weak rear legs or wobbling is common in cats with diabetes. In dogs, cataracts and blindness can developed suddenly, even when no other signs of the disease are present. Lab tests usually show elevated blood sugar and/or glucose in the urine.

Treatment: Only a handful of cases can be treated with oral insulin-enhancing drugs; most animals require insulin injections. Some cats experience transient DM, where the insulin requirement comes and goes without any logical pattern .

Hyperthyroidism

What Is It: Hyperthyroidism is one of the most common endocrine conditions affecting older cats. It is caused by an increase in production of the thyroid hormone, which controls the body's metabolic rate. Cats suffering from hyperthyroidism burn energy faster than they can consume it, so they tend to lose weight. The disease eventually affects other organs in the animal’s body and can result in high blood pressure, intestinal problems, and renal failure. If the disease is diagnosed early, it can be quite manageable.

Symptoms: Lethargic behavior or hyperactivity, irritability, weight loss, slow heart rate, low body temperature, muscle weakness, elevated cholesterol, hair loss, cold intolerance, frequent ear and skin infections. A simple blood test can determine thyroid function levels. An elevated level of thyroxine (T4) would confirm hyperthyroidism.

Treatment: The most common form of treatment is medication in the form of a Carbimazole tablet, which needs to be administered daily for the rest of the pet’s life. Radioactive iodine therapy is a 95 percent effective cure consisting of a single injection of radioactive iodine. The injection is harmless to cats (only attacks ailing thyroid tissue) but dangerous to humans, so the cats can only be treated in certain hospitals and will have to remain hospitalized for up to 6 weeks following treatment, to make sure radioactive levels decrease.

Cancer

What Is It: Cancer is a frequent problem in older pets. Mast cell tumors are the most common (and most fatal) type of cancer in dogs. Female pets that have not been spayed are prone to mammary tumors, which are often malignant and very hard to treat. Cancer, however, is not always fatal, especially when detected early and treated aggressively.

Symptoms: Weight loss, lethargy, weight loss, repeated infections, nausea, blood in the urine or stools, frequent infections, abdominal swelling, lumps, pain; many other symptoms associated to particular types of cancer.

Treatment: Surgery, chemotherapy, and radiation therapy.