Key takeaways from AAHA’s 2026 oncology guidelines

Cancer is a leading cause of illness and death in older dogs and cats, affecting roughly 50% of dogs and about 30% of cats older than 10 years. The American Animal Hospital Association’s (AAHA) 2026 Oncology Guidelines synthesize current evidence and expert consensus into actionable recommendations for the primary care team from diagnosis and staging to treatment options, supportive care, referral triggers, and follow-up.1,2

Here are a few key takeaways. A link to the full guidelines can be found in the reference list below this article.

Make a definitive diagnosis before planning therapy

AAHA emphasizes that a cytologic or histopathologic diagnosis is necessary to determine prognosis and guide therapy.1-3 When fine-needle aspirate is inconclusive or additional information is required (for example, tumor grade), pursue biopsy and histopathology rather than assuming tumor behavior.3

Use staging to guide treatment intent and timing

Staging is more than local vs metastatic classification. It clarifies treatment intent (curative vs palliative) and identifies appropriate imaging and nodal assessment. AAHA provides tumor-specific staging checklists and recommends thoracic imaging, abdominal ultrasound, and regional lymph node cytology or biopsy as indicated.3

Frame chemotherapy around quality of life

The primary goal of systemic therapy in veterinary oncology is maintaining the best possible quality of life while controlling disease. Most veterinary chemotherapy protocols are generally well tolerated. Adverse events are usually manageable when clinicians and owners anticipate them and monitor appropriately.1,4

Educate owners proactively about the likelihood of appetite changes during chemotherapy and provide concrete management strategies. Addressing appetite loss early helps pets remain on recommended treatment plans and improves overall well-being during therapy.1

Evaluate new drugs and biologics carefully

The guidelines stress understanding the risks, benefits, cost, and regulatory status of novel therapeutics (such as small-molecule inhibitors, monoclonal antibodies, and other biologics). Clinicians should not adopt new agents without reviewing available evidence, registration status, and monitoring requirements.4

Integrate supportive and symptomatic care from diagnosis onward

Supportive care—nutrition, pain management, antiemetics, wound and infection management, and psychosocial support for owners—is fundamental and begins at diagnosis. AAHA provides screening and treatment checklists aimed at maintaining function and comfort throughout therapy and survivorship.7,8 When initiating symptomatic care, thoroughly evaluate for comorbidities that may alter drug choice, dosing, or prognosis. This ensures supportive measures truly improve quality of life rather than introducing harm.1

Optimize the veterinary team’s role

Technicians and other team members play a central role in oncology workflows, including intake screening, weight and appetite tracking, pain scoring, client education, medication administration training, and documentation. Standardized technician checkpoints improve early detection of complications and support better quality-of-life decisions.8

Know when to refer and how to collaborate

AAHA outlines clear referral triggers: complex staging that requires advanced imaging, specialized surgery, administration of advanced systemic protocols, or when weighing curative versus palliative intent. Good referral relationships and succinct transfer-of-care notes streamline transitions and may improve outcomes.5,6

Adopt structured post-treatment monitoring

Tumor-specific follow-up schedules and standardized monitoring (physical exam, imaging, and laboratory testing) are recommended to detect recurrence or late treatment effects early. Integrating these schedules into practice management software reduces the risk of patients being lost to follow-up.9

References

1. American Animal Hospital Association. 2026 AAHA oncology guidelines for dogs and cats. American Animal Hospital Association. Published January 1, 2026. Accessed January 7, 2026. https://www.aaha.org/resources/2026-aaha-oncology-guidelines-for-dogs-and-cats/
2. American Animal Hospital Association. Section 1: overview of common cancers. American Animal Hospital Association. Published January 1, 2026. Accessed January 7, 2026. https://www.aaha.org/resources/2026-aaha-oncology-guidelines-for-dogs-and-cats/section-1-overview-of-common-cancers/
3. American Animal Hospital Association. Section 3: tumor diagnostics and staging. American Animal Hospital Association. Published January 1, 2026. Accessed January 7, 2026. https://www.aaha.org/resources/2026-aaha-oncology-guidelines-for-dogs-and-cats/section-3-tumor-diagnostics-staging/
4. American Animal Hospital Association. Section 5: therapeutic interventions. American Animal Hospital Association. Published January 1, 2026. Accessed January 7, 2026. https://www.aaha.org/resources/2026-aaha-oncology-guidelines-for-dogs-and-cats/section-5-therapeutic-interventions/
5. American Animal Hospital Association. Section 6: consultations and referrals. American Animal Hospital Association. Published January 1, 2026. Accessed January 7, 2026. https://www.aaha.org/resources/2026-aaha-oncology-guidelines-for-dogs-and-cats/section-6-consultations-and-referrals/
6. American Animal Hospital Association. Section 2: what's new in veterinary oncology. American Animal Hospital Association. Published January 1, 2026. Accessed January 7, 2026. https://www.aaha.org/resources/2026-aaha-oncology-guidelines-for-dogs-and-cats/section-2-whats-new-in-veterinary-oncology/
7. American Animal Hospital Association. Section 7: supportive and symptomatic care. American Animal Hospital Association. Published January 1, 2026. Accessed January 7, 2026. https://www.aaha.org/resources/2026-aaha-oncology-guidelines-for-dogs-and-cats/section-7-supportive-and-symptomatic-care/
8. American Animal Hospital Association. Section 8: technician and team optimization. American Animal Hospital Association. Published January 1, 2026. Accessed January 7, 2026. https://www.aaha.org/resources/2026-aaha-oncology-guidelines-for-dogs-and-cats/section-8-technician-and-team-optimization/
9. American Animal Hospital Association. Section 9: post-treatment monitoring and follow-up care. American Animal Hospital Association. Published January 1, 2026. Accessed January 7, 2026. https://www.aaha.org/resources/2026-aaha-oncology-guidelines-for-dogs-and-cats/section-9-post-treatment-monitoring-and-follow-up-care/