Evaluating the Unhealthy Senior Pet

Senior pets are at greater risk for illness to occur in their final years, although the incidence and mortality for all diseases combined have shifted over time primarily due to improved preventive medicine measures, diagnostic advances, better nutrition, and greater access to veterinary health care.

Prevention and screening for chronic diseases are discussed in the section “Evaluating the Healthy Senior Pet” and can establish a baseline for healthy senior pet care. When disease does occur in senior pets, the history, physical examination, and diagnostic tools can help establish a diagnosis and determine a course for care. Interpreting diagnostic tests and reaching a clinical diagnosis should be congruent with clinical presentation, laboratory values, imaging, histopathology, and epidemiology.

Common clinical signs of chronic disease may include malaise, progressive lethargy, behavior changes, hyporexia, anorexia, altered thirst pattern, weight loss over time, mobility alterations, and nonhealing wounds. A suspected chronic disease can often be presumptively diagnosed based on the client’s account of the pet’s history and physical examination, although it is recommended to perform appropriate clinicopathological evaluations. The minimum database for a senior pet should include a detailed blood profile including thyroid panel and urinalysis. Additional screening or diagnostic tests may be used depending on the minimum database and may include thoracic, abdominal, and other imaging. Diagnostic approaches for senior dogs and cats based on body system are summarized in Table 2, Diagnostic Approaches by Body System for Senior Dogs and Cats.38 This list is not exhaustive and additional diagnostic approaches may be warranted.

Unknown Diagnosis or Comorbidities

Senior pets may have several concurrent medical issues and associated clinical signs. These complex cases may be referred to an appropriate specialist. Alternatively, the client may opt for palliative care, and it may be helpful to have a trained palliative care veterinarian to consult with on the case.

There may be clients who do not wish to pursue diagnostics for a number of reasons, including the age of the pet, concern and fear of certain test procedures or outcomes, and financial constraints. If the client chooses to not pursue diagnostics or treatment, veterinarians should discuss the benefit of symptomatic treatment and how it can improve the pet’s QOL. This may encourage the client to access and continue palliative care. If the client chooses to seek additional diagnostics, then either performing them or seeking referral to a specialist may be indicated for complex comorbidities.

Download PDF of Table 2: Diagnostic Approaches by Body System for Senior Dogs and Cats.

Body System Diagnostic Approach Therapeutic Tip


PE focus: Identify, describe, and map skin lesions, i.e., pruritus, alopecia. Do not forget nails, nail beds, and interdigital spaces.

Baseline dermatology diagnostic evaluation should include:

  • Senior blood profile with urinalysis
  • Skin scraping/impression cytology of any lesions
  • Dermatophyte testing if concerned about fungal disease
  • Measuring, mapping and aspiration of any growths
  • Other integument issues regarding nails, nail beds; ears may need different care
  • Evaluate for pain
  • For malignant conditions, consider thoracic and abdominal imaging as part of the clinical staging

The Guidelines task force encourages skin biopsy in senior pets presented with chronic dermatopathy if the baseline diagnostics are negative.

Recommend referral to a specialist for chronic, progressive, or neoplastic cases.

  • Avoid steroid use if possible until a microscopic diagnosis is established.
  • Recognize that dermatologic issues may also have a pain component and should be treated for pain.
  • Use validated scales to monitor progression of treatment as appropriate.1


PE focus: Oral cavity, with particular focus on fractured, loose teeth, foreign bodies, oral ulcers, inflammation, masses. Make note of degree of dental disease and ability to prehend and swallow. Head and neck palpation.

Baseline diagnostic evaluation should include:

  • Senior blood profile with urinalysis

Additional diagnostic tests:

  • Complete visual examination of the entire oral cavity with general anesthesia
  • Head and neck radiographs
  • Skull CT may be useful
  • Staging procedures is a viable plan.


PE focus: Mucous membrane color, capillary refill time, abdominal palpation, lymph node palpation.

Baseline diagnostic evaluation should include:

  • Senior blood profile with urinalysis
  • Lymph node aspiration if indicated

Additional diagnostic tests:

  • CBC with pathology evaluation for cell morphology
  • Imaging to rule out secondary etiology for hematologic abnormality
  • Coagulation profile
  • Flow cytometry in select cases
  • Bone marrow aspirate

GI/Hepatic/ Biliary

PE focus: Abdominal palpation, noting enlargement of organs, thickening, masses. Color of mucous membranes, skin (inner ear pinnae), conjunctiva, noting if jaundice present.

Baseline diagnostic evaluation should include:

  • Senior blood profile with urinalysis
  • Thoracic radiographs
  • Abdominal radiographs

Additional diagnostic considerations:

  • Abdominal ultrasound
    • Tip: If ultrasound shows thickened muscularis layer, then laparoscopic or surgical biopsies appear to be more diagnostic.
  • Rectal examination
  • Gastrointestinal panel
  • Bile acids
  • Endoscopy/colonoscopy
  • Enzymes or probiotics may be useful based on the individual patient.
  • Appetite stimulants and meat puree treats can be used for cats who are hyporexic or anorexic.
  • Recommend medication for nausea, as well as appetite stimulants as indicated.

Renal/ Urogenital

PE focus: Evaluate muscle condition score, body condition score, size and shape of kidneys, propensity for crystal or stone formation, indications of neoplasia.

Baseline renal diagnostic evaluation should include:

  • Senior blood profile with urinalysis
    • Tip: Monitor and record early trends in SDMA, creatinine, and USG (making a chart of these indicators may be helpful)
    • If proteinuria present, UP:UC ratio
  • Blood pressure
  • Urine culture if indicated
    • Distinguish bacteriuria/pyuria from infection

For patients with renal disease identified with screening tests:

  • Abdominal imaging (radiographs and ultrasound may both be useful; however, ultrasound may be preferred for a solitary test)
  • Monitor blood pressure more frequently in patients with chronic kidney disease
  • Continued monitoring of bloodwork, SDMA, BUN, creatinine
  • Continued monitoring for proteinuria

For patients identified with uroliths:

  • Surgery may be indicated
  • Diet change may be indicated

For patients identified with neoplasia:

  • Additional staging recommended
  • Referral to a veterinary oncologist should be considered
  • Maintaining hydration is imperative.
  • Provide daily fluid therapy for patients when indicated, recognizing this may be earlier for senior patients, and may include parenteral, subcutaneous, or intravenous fluid therapy.
  • Adopt an antimicrobial approach to urinary tract infections.2
  • Recognize renal failure may create pain and/or pruritus (this is recognized in humans).3


PE focus: Full neurologic examination with checklist.4,5

Baseline diagnostic evaluation should include:

  • Senior blood profile with urinalysis
  • Full neurologic examination

Additional diagnostic tests to consider:

  • SOD-1 testing for degenerative myelopathy
  • MRI
  • DISHAA or other questionnaires for cognitive dysfunction syndrome6
  • Ultrasound, chest radiograph

Diagnostic tips:

  • Rule out syncope vs. seizure
  • Palpate axillae for pain from a nerve sheath tumor
  • Evaluate client video for all conditions
  • Evaluate toenail wear

Consider referral to a neurologist for further workup/MRI:

  • Include any client video with referral materials
  • Use multimodal therapy.


PE focus: General body appearance, palpation of thyroid, abdominal palpation, concern for hair loss, distended abdomen, redistribution of fat, and eye changes, including corneal, anterior chamber, lens, pressures, tear production, retina.

Baseline diagnostic evaluation should include:

  • Senior blood profile with urinalysis

Additional diagnostic tests to consider:

  • Special hormonal assays depending on suspected disease
  • Regional imaging and advanced imaging with CT is often necessary

Additional testing for chronic disease:

  • Hyperthyroid/Hypothyroid: Monitor T4, calcium levels
  • Hyperadrenocorticism:
    • ACTH stimulation test or low-dose dexamethasone suppression test
    • Monitor adrenal size with ultrasound
  • Hypoadrenocorticism: ACTH stimulation test
  • Diabetes: periodic or continuous glucose monitoring, fructosamine, urinalysis to monitor for ketones, urinary tract infection, hematuria
  • Hyperparathyroidism: Monitor calcium, phosphorus levels, urinalysis for urinary tract infection
  • Hypoparathyroidism: Monitor calcium leve
  • The FreeStyle Libre sensor can provide continuous monitoring for diabetic animals for up to 14 days (see the 2018 AAHA Diabetes Management Guidelines for Dogs and Cats).7

Cardiac/ Respiratory

PE focus: Auscultation of heart and lungs, identify normal and abnormal rhythm, breath sounds, muffled chest sounds, locations of abnormality.

Baseline cardiac/respiratory diagnostic evaluation should include:

  • Senior blood profile with urinalysis
  • Thoracic radiographs
  • Echocardiogram
  • Blood pressure
  • NT-proBNP

Additional diagnostic considerations:

  • Abdominal imaging if necessary
  • Respiratory: Infectious disease evaluation (PCR methods preferred)
  • Dogs with pacemakers often do well.
  • Consider working with a rehabilitation specialist for therapy options.
  • Owner education is key to therapeutic management.


PE focus: General body palpation with focus on spine, limbs, joints, muscular condition score, movement examination, full orthopedic examination, evaluation of pain level.

Baseline diagnostic evaluation should include:

  • Senior blood profile with urinalysis

Additional diagnostic tests:

  • Regional radiographs
  • Arthrocentesis
  • Consider a diagnostic round of pain control.
  • Use multimodal pain management when possible.
  • Make recommendations for clients interested in using harnesses, slings, etc.
  • Encourage clients to video their pets when they are monitoring pain and mobility as this can provide valuable insight to guide treatment.

1 Olivry T, Saridomichelakis M, Nuttall T, et al. Validation of the Canine Atopic Dermatitis Extent and Severity Index (CADESI)-4, a simplified severity scale for assessing skin lesions of atopic dermatitis in dogs. Vet Dermatol. 2014;25(2):77-e25. doi:10.1111/vde.12107

2 See Frey E, Costin M, Granick J, Kornya M, Weese JS. 2022 AAFP/AAHA Antimicrobial Stewardship Guidelines. J Am Anim Hosp Assoc. 2022;58(4):1–5. doi:10.5326/1547-3317-58.4.1. Available at aaha.org/antimicrobials.

3 O'Connor NR, Corcoran AM. End-stage renal disease: symptom management and advance care planning [published correction appears in Am Fam Physician. 2012 May 15;85(10):950. Dosage error in article text]. Am Fam Physician. 2012;85(7):705–710.

4 Averill DR Jr. The neurologic examination. Vet Clin North Am Small Anim Pract. 1981;11(3):511–521. doi:10.1016/s0195-5616(81)50056-8

5 Chrisman C. Step-by-step: the neurologic examination. Clinician's Brief. May 2018. Available at https://www.cliniciansbrief.com/article/step-stepneurologic-examination.

6 O'Brian ML, Herron ME, Smith AM, Aarnes TK. Effects of a four-week group class created for dogs at least eight years of age on the development and progression of signs of cognitive dysfunction syndrome. J Am Vet Med Assoc. 2021;259(6):637–643. doi:10.2460/javma.259.6.637

7 Behrend E, Holford A, Lathan P, Rucinsky R, Schulman R. 2018 AAHA Diabetes Management Guidelines for Dogs and Cats. J Am Anim Hosp Assoc. 2018;54(1):1–21. doi:10.5326/JAAHA-MS-6822/

ACTH: adrenocorticotropic hormone
BUN: blood urea nitrogen
CBC: complete blood count
CT: computed tomography scan
NT-proBNP: N-terminal pro B-type natriuretic peptide
PCR: polymerase chain reaction
PE: physical examination
SDMA: symmetric dimethylarginine assay
SOD-1: superoxide dismutase
T4: thyroxine
UP:UC ratio: urine protein to creatinine ratio
USG: urine specific gravity

The 2023 AAHA Senior Care Guidelines for Dogs and Cats are generously supported by Boehringer Ingelheim Animal Health, CareCredit, IDEXX, and Zoetis.

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