GERIATRIC CARE FOR DOGS

VetSuite Veterinarians
General Practice & Preventative Medicine

Pets today are living longer and have better quality lives than ever before, thanks to improved nutrition and veterinary care, as well as better-educated owners. This increased longevity means that more dogs are faced with the special demands and problems that become apparent with age. Understanding the aging process and the most common problems that face the aging dog is the first step in providing the best possible care to geriatric patients. The main focus of geriatric health care is owner education and the early detection and prevention of disease.

It is important to realize that aging itself is not a disease; it is simply a stage of life. Increasing age causes a gradual decline in the body's ability to repair itself, to maintain normal body functions, and to adapt to stresses and alterations in the environment. Many changes occur in dogs as they age. For example, metabolism often decreases, so less food is required. Older dogs are also usually less active and thus, commonly gain weight, making obesity one of the more frequent problems seen in the senior dog.

With time, dogs begin to have a gradual decline in their hearing, smell, vision and taste. It is not uncommon for older dogs to spend more time sleeping and be more difficult to arouse. Additionally, the function of the immune system is compromised with increasing age. Metabolic and endocrine problems, organ dysfunction, and cancer are all seen with increased frequency in the geriatric dog. Degenerative changes in the muscles, bones and joints may be manifested as arthritis and muscle weakness.

THE AGING DOG

Dogs age at different rates, depending on their body type. In general, smaller breeds live longer than larger dogs, and mixed breed dogs live longer than pure bred dogs.

A general guideline as to when a dog might be considered geriatric is based on the dog's adult weight.

• Small dogs (< 20 pounds) are considered geriatric between 9 to 13 years of age.
• Medium sized dogs (21 to 50 pounds) are considered geriatric between 9 to 11 years of age.
• Large breed dogs (51 to 90 pounds) are considered geriatric between 7.5 to 10.5 years of age.
• The giant breed dogs (> 90 pounds) are usually considered geriatric between 6 to 9 years of age.

ADVANTAGES OF A GERIATRIC PROGRAM

Developing and following a geriatric health plan can detect disorders and diseases early enough to allow medical or surgical intervention. Some disorders of the geriatric dog may be difficult to help; however, with early intervention it is usually possible to make significant improvements in the quality of the pet's life. The goal of any geriatric health program is to prevent or delay the development of disorders associated with aging.

RECOMMENDED DIAGNOSTICS

Regularly scheduled geriatric examinations and diagnostic tests are recommended to ensure that early stages of disease are discovered and appropriate treatment plans instituted. The most common diagnostic tests performed as part of a complete geriatric work-up include:

• Complete medical history - Asking the right questions is very important in obtaining a thorough geriatric health history. The owner or a health professional can complete a specific geriatric health questionnaire. It is important that specific questions be asked that are designed to uncover problems that an owner may simply attribute to "old age" or "just something that they expect to live with." Often these are signs of underlying disease and are very treatable.
• Complete physical examination - A complete physical examination is performed at each exam. The eyes are examined for age-related changes such as lenticular sclerosis or cataracts. Funduscopy also provides valuable information on the systemic status of the dog. The ears are examined for signs of infection or allergies. The mouth, gums and teeth are evaluated, with dental disease and gingivitis being common findings. Lymph nodes are palpated for enlargement. The skin and quality of the hair coat are observed. Skin tumors are a common finding, and a poor hair coat or a lack of grooming may be signs of allergies, parasites, infections or systemic illness. The heart and lungs are ausculted and new cardiac murmurs noted. The abdomen is palpated for masses or organomegaly. Rectal examination is performed in all male dogs. Finally, the general body condition and weight are recorded.
• Complete blood count - In older animals, anemia is not an uncommon finding and requires further diagnostic testing. The total white count and cell differential are also evaluated.
• Biochemistry profile - The biochemistry profile may indicate renal or hepatic abnormalities, diabetes mellitus, alterations in electrolytes and cholesterol, and suspicious evidence of hypothyroidism and adrenal disorders.
• Urinalysis - Analysis of the urine helps detect inability to concentrate the urine as occurs with renal insufficiency. It also helps to detect underlying urinary tract infection and the presence of glucosuria, hematuria, etc.
• Fecal examination - Because gastrointestinal parasites are sometimes more debilitating in geriatric animals, a yearly fecal exam is recommended. Additionally, some parasites have zoonotic potential, re-enforcing the value of yearly fecal exams. Routine fecal floatation and specific tests for Giardia are recommended.
• Heartworm test - Heartworm tests are performed on an annual basis in animals that are not on year round prophylaxis and are recommended at least every other year for animals that receive continuous prophylaxis.

The above parameters represent the most routine diagnostic tests that are included in a geriatric health program. Based on their results, additional testing to consider include:

• Aspiration of skin masses - One of the more common findings on the physical examination of older dogs is dermal or epidermal masses. In most cases these are benign tumors or cysts. The size and location of all masses are recorded in the medical record, so that changes in previous masses or the development of new masses can be noted. Each individual mass is also aspirated for cytologic examination.
• Endocrine function tests - Common endocrine problems of older dogs are hypothyroidism and hyperadrenocorticism. A thyroid panel (T4, free T4, canine TSH assay) is done to search for hypothyroidism. Tests to diagnose adrenal disorders include an ACTH stimulation test and a low dose dexamethasone suppression test.
• Radiography - Chest radiographs are part of a cardiac work-up if a new murmur is found, if a previously diagnosed murmur is being monitored, and as a screening tool for metastasis. Abdominal radiographs are indicated if organ dysfunction is documented on laboratory tests or if organ enlargement or masses are palpated.
• Blood pressure measurement - Hypertension is increasingly identified in the geriatric dog. It is usually associated with diseases such as kidney disease and hyperadrenocorticism.
• Cardiac evaluation - If there is indication of potential heart disease such as a newly discovered or a worsening murmur, an arrhythmia or gallop rhythm, muffled heart sounds, or episodes of weakness or collapse, a more complete cardiac evaluation is indicated. Chest radiographs, an electrocardiogram (ECG), and an echocardiogram define the extent and potential cause of the cardiac disease. They also define whether treatment is required at the time and what therapies are appropriate.
• Abdominal ultrasonography - Abdominal ultrasonography offers a non-invasive method of visualizing the abdominal organs and any associated parenchymal changes. It provides valuable information that compliments the information obtained with plain radiography.

RECOMMENDED TREATMENTS

• Vaccinations - All dogs must receive rabies vaccinations as required by state law. Other vaccines are given as appropriate for individual needs. The frequency of vaccination and the duration of common vaccines is currently under debate. Although the suggested manufacturers' frequency is usually once a year for many vaccines, this recommendation is being reviewed. With the exception of bacterial bacterins, duration may, in fact, be much greater than one year for most vaccines.
• Nutritional concerns - Administering the proper diet is very important to the geriatric dog. There is no "best" food to feed a geriatric dog. The ideal diet depends on the specific problems or nutritional requirements of the individual animal.
• For example, obesity is a serious concern in the geriatric animal because it directly correlates to a decreased longevity, and may contribute to other health problems. For some animals, low calorie, high fiber diets make weight loss easier.
• Additionally, through the geriatric work-up, special nutritional changes may be recommended. Special diets attempt to slow the development of the disease process or to improve specific organ function by decreasing that organ's workload. Special diets are available for many diseases (even in the early stages) including kidney, liver, gastrointestinal, heart, dental and skin diseases, as well as for diabetes mellitus and cancer.
• Dental disease - Dental disease and gingivitis are common findings in geriatric dogs. Left untreated, dental disease usually leads to tooth loss and may serve as a nidus of infection for the rest of the body.
• Degenerative joint disease (DJD) - DJD is also common in older dogs. Signs of arthritis include lameness, stiffness, difficulty rising, trouble navigating stairs or jumping, falling on slippery floors, difficulty getting comfortable or being restless at night. Within the past few years there have been many developments in the treatment of DJD, and many new pharmaceutical and neutraceutical products are now commercially available.
• Metabolic problems - A major benefit of routine geriatric laboratory testing is the early detection of a variety of metabolic conditions. Examples include finding evidence of mild, asymptomatic kidney disease, liver disease, hypercalcemia, lipemia, hypo- or hyperproteinemia. When marginal changes are found in laboratory tests, it is advisable to repeat the test to verify the existence of a true alteration. Once a definite change is documented, then further work-up is indicated to investigate the cause and the significance of the abnormality.
• Endocrine disorders - Endocrine problems may be suspected based on historical, physical or laboratory findings. The most common endocrine problems affecting geriatric dogs are diabetes mellitus, hyperadrenocorticism (Cushing's disease), and hypothyroidism. Interventive therapy prolongs the life of dogs with all three conditions, and is frequently easier if serious secondary problems have not yet developed.
• Cardiac disease - Newly discovered heart murmurs are a common finding when ausculting the geriatric dog. Many times the murmurs are found before a dog is symptomatic. Accurate auscultation and recording of the intensity, type, and character of the murmur is important at each examination. Further diagnostics are warranted for all significant murmurs or for mild murmurs that are progressing in intensity.
• Skin tumors - On the basis of the size, location and aspiration results, removal of certain skin masses may be recommended. If masses are not removed and submitted for histopathology, then the owner is instructed to monitor them for changes in size, shape or texture.
• Urinary problems - Determining whether a dog has polydipsia, polyuria, or incontinence is one diagnostic dilemma when taking a history on urinary patterns. The treatment for such signs varies greatly, depending upon the actual condition and its cause. Careful history taking and a complete medical work-up are often needed to differentiate these conditions.
• Prostate problems - If the dog is an intact male, he is at significant risk of prostatic disease as he ages. Prostatic infections, hyperplasia, abscesses, cysts, and neoplasia are all potential problems in the intact male. A rectal examination to evaluate the prostate is an important component of each examination of the geriatric male dog.
• Neoplasia - Cancer is a significant problem in the geriatric dog. Some breeds such as the golden retriever and boxer are at increased risk for the development of cancer, and some cancers show a predilection for various dog breeds. Major advances in veterinary oncology now provide many different avenues of diagnosis and treatment of many forms of cancer.
• Behavioral and cognitive dysfunction - As dogs age they may experience deterioration of their mental cognitive functions, similar to aging people. They may become more "set in their ways," more inflexible, less patient and more irritable. They may forget learned behaviors such as normal urinary and defecation habits. They may sleep more and be less responsive to external stimuli. It is important to differentiate whether these signs are related to an underlying disease process, or are due to a decline in their sensory awareness and cognitive behavior. If no underling systemic causes of the deterioration can be identified, medications that treat cognitive dysfunction, such as L-deprenyl, may be considered.

SUGGESTED GERIATRIC HEALTH PROGRAM

It is advisable to perform complete physical examinations at least twice a year in geriatric dogs. A complete laboratory database is obtained annually (as outlined above), and more frequently if abnormalities are found. During each exam, the owners are educated on such subjects as skin, ears and dental care and nutrition. Obese patients are placed on a weight control program.

For animals with significant health concerns, physical examination is recommended every 2 to 3 months, or as indicated by the underlying disease process. Laboratory monitoring is performed as indicated for the various diseases diagnosed. Annual thyroid function tests, an ECG, and thoracic radiographs are also considered for animals ill with other diseases.