Approach to the sick or unhealthy senior pet

Common clinical conditions

Although senior dogs and cats are affected by many of the same conditions as younger animals, some disorders are of particular significance in the senior pet. These disorders include, but are not limited to, those listed in Table 2.25-39

Malignant neoplasia is a frequent finding in senior pets, and this is often a life-limiting ailment. Lists of the most common neoplastic conditions are found in a variety of texts and articles.40,41 It is important to note that a number of cancers are easily misdiagnosed or overlooked early in their disease process. Special consideration should be given to the following common, but often elusive and illusory, neoplastic conditions:

  • Squamous cell carcinoma: appearing as nail bed disease (dog) or facial dermatosis (cat)
  • Squamous cell carcinoma, melanoma, and fibrosarcoma of the oral cavity: emanating from the gingiva, tongue, or tonsil
  • Osteosarcoma causing lameness
  • Fibrosarcoma, mastocytoma, hemangiopericytoma: presenting as soft-tissue cutaneous or subcutaneous masses
  • Mammary adenocarcinoma: appearing as a swelling or cyst along the mammary chain
  • Lymphosarcoma: producing alimentary signs, soft-tissue masses, and organomegaly (e.g., hepatomegaly in the dog, renomegaly in the cat), and at other extra-nodal sites
  • Bladder or urethral carcinoma: presenting as dysuria or hematuria

Evaluation of the sick senior animal

First read and follow the healthy-animal assessment guidelines, above. Obtain a comprehensive history, observe the animal, and perform a complete and thorough physical examination, as described for the healthy senior pet. Pay particular attention to any clinical changes or signs of pain.

  • Include in the minimum laboratory database all tests for evaluation of the healthy senior, with the addition of serum electrolytes, phosphorus, bicarbonate, total carbon dioxide, and arterial blood pressure.
  • Tests for feline leukemia virus and feline immunodeficiency virus should be performed in potentially exposed cats.
  • Possible additional tests are listed in Table 3. Client Communication and Education Clients overwhelmingly prefer to be told about all the best options, even those options the veterinarian may think the client will decline.42 The veterinarian has a responsibility to recommend what is best for the pet, but the chosen treatment must be what is best for both the patient and the client.
  • In recommending a treatment for a pet, thoroughly and impartially evaluate and communicate the consequences of the choices for the pet and client. Involve and empower clients in the decision-making process, making clear their role and responsibilities.
  • Design treatment protocols that optimize compliance. Ensure clients are capable of administering the treatment plan mentally, physically, and emotionally, as well as by the route and timing prescribed. If the requirements cannot be accomplished, consider alternative delivery systems, routes, and intervals that have been documented to be effective.
  • Senior pets receiving treatment have an increased need for more frequent examinations and testing (new and follow-up). Care of senior pets also necessitates more frequent communication with the client and documentation of progression or regression of signs. Educate clients about the pet’s disease state, diagnosis, prognosis, and treatment side effects. Discuss the time commitment and any quality-of-life issues. Educate and communicate with clients both verbally and in writing to better gain a clear understanding of their expectations and revise any expectations that are not realistic.
  • Thoroughly document differential diagnoses and assessments in a problem-oriented format. Whenever possible, record a diagnosis and the animal’s short-term, intermediate, and long-term prognoses, even if such assessments are temporarily presumptive or tentative.

Choosing appropriate treatments

Consider all of the pet’s conditions and the best available scientific evidence when designing a treatment plan. Specifically, contradictions or contraindications among diseases, drugs, and diets may necessitate prioritizing modalities for an optimal outcome and/or quality of life.

  • Avoid indiscriminate use of antimicrobial agents.
  • Avoid drugs that may impair mobility and behavior or those that may change blood pressure (e.g., sedative, sympathomimetic, or anticholinergic drugs).
  • Consider interactions, compatibilities, and incompatibilities among drugs and biologics.43,44
  • Nonsteroidal antiinflammatory drugs (NSAIDs) are commonly dispensed and can be beneficial for senior pets, but precautions include the following:
    • Monitor for potential complications, especially when the pet is known or suspected to have hepatic or renal disease, hyperadrenocorticism, or any condition that may predispose to gastrointestinal erosion or ulceration.
    • Ensure that the client understands the vital importance of not changing the dose or type of NSAID without consulting the veterinarian.
    • Avoid the concurrent use of two NSAIDs or the concurrent use of a corticosteroid with an NSAID, which potentially causes severe side effects.45


Veterinarians and clients share responsibility for monitoring for side effects or complications. Require clients to closely monitor the intake of any medication administered in food. Cats in particular may develop food aversion if they are given medication by this route. Consider using flavored or formulated medications instead. Modify drug dose or dosing interval based on renal and hepatic function. Perform drug concentration testing when appropriate. Each disease state may require specific monitoring tests (e.g., fructosamine or blood glucose curve for diabetes mellitus; tonometry for glaucoma; blood pressure measurements for hyperthyroidism, chronic renal failure, and heart disease). Consider the effects of each drug on other diseases (e.g., furosemide, NSAIDs, or methimazole on renal failure), and alter treatments as necessary based on response.

Additional considerations

A formal hospital callback or client follow-up system is crucial to successful case management. Consider other resources such as consultation and/or referral to a specialist based on the type of disease, the veterinarian’s level of expertise, and the available equipment (e.g., magnetic resonance imaging, computed tomography, endoscopy). The use of electronic media and communication to transmit and gather information facilitates remote consultations with specialists.