Revamped AAHA oncology guidelines coming in 2026

In early 2026, the American Animal Hospital Association (AAHA) plans to release updated oncology guidelines designed for general practitioners (GPs) to assist them in managing cancer cases in everyday practice.

AAHA announced the launch at its recent annual conference (AAHA CON), held September 11-13 in Chicago.

The update will mark 10 years since the AAHA oncology guidelines were first released.

In an interview with AVMA News, Dr. Jessica Vogelsang, AAHA's chief medical officer, talked about the intent behind the 2026 AAHA Oncology Guidelines.

"We live in a world where there's more interest than ever in treating pets for cancer, and yet it's increasingly difficult to access that specialty level of care—whether it's because of cost or there aren’t enough oncologists," she said. "This guideline is really meant to help general practitioners identify the things that they can do, because there is a lot they can do … so they feel more comfortable saying, 'I can help.'"

Helping general practitioners

Dr. Sue Ettinger, a board-certified veterinary oncologist, was a part of the AAHA task force that updated the oncology guidelines. She previewed the 2026 guidelines during AAHA CON.

Across three Merck Animal Health–sponsored sessions at AAHA CON, Dr. Ettinger discussed why veterinary oncology matters in general practice and medical advancements in the last decade that make cancer detection and treatment more accessible.

The guidelines were developed with the goal to provide GPs an understanding of what an appropriate workup for these cases looks like, as well as when to treat, when to consult, and when to refer.

"Hopefully these guidelines will provide you with structure and confidence for working up cases and potentially treating them," said Dr. Ettinger.

For example, Dr. Ettinger said, mast cell tumors (MCTs) typically do not metastasize to the lungs, so taking a chest radiograph in a 3-year-old Boxer with newly diagnosed MCT wouldn't be necessary, especially if the owners are on a budget.

The 2026 AAHA Oncology Guidelines—which follow the association's referral guidelines on fostering stronger collaborations between primary care and specialty care teams—underscore the essential partnership between oncologists and GPs. The oncology guidelines further delve into the interconnected roles of teleconsulting and "veterinary technicians as oncology extenders."

The updated guidelines address, among other topics, practical tools and therapies, patient monitoring, supportive care, pain management, nutritional support, interprofessional collaboration, client communication, and palliative and end-of-life care, as well as chemotherapy safety for veterinary staff and clients handling pets.

The document outlines common cancers in dogs and cats by tumor type and behavior, along with respective staging tests, treatment options, prognosis, and known negative prognostic factors, to give GPs a quick reference guide that can help facilitate initial conversations with clients and support team training.

Also included are Dr. Ettinger's "three P's" to consider—prognostic, practical, and pertinent—in a cancer workup to help inform decisions.

'Game changers'

The guidelines also discuss "game-changing" novel cancer therapies since 2016, such as Stelfonta, Tanovea, Laverdia-CA1, Gilvetmab, and Canalevia-CA1, which have either been fully or conditionally approved by the Food and Drug Administration (FDA) or licensed by the U.S. Department of Agriculture.

Dr. Ettinger, who disclosed she speaks and consults for several drug companies, including the maker of Stelfonta, shared her enthusiasm about the tigilanol tiglate injection. Developed by QBiotics, the injectable therapy was approved by the FDA in 2020 for the treatment of dogs with nonmetastatic, cutaneous mast cell tumors. The intratumoral injection is also indicated to treat nonmetastatic, subcutaneous MCTs located in particular areas of a dog’s leg.

She noted it is not a chemotherapeutic, but an anticancer agent that works by targeting the blood vessels feeding cancer cells, causing the tumor to separate and fall off, which forms a wound.

"We celebrate the wound. The wound means it’s working," Dr. Ettinger said, cautioning that it may have some odor and discharge but advising leaving it open as it often heals on its own by four to six weeks.

Dr. Ettinger encouraged more veterinarians to look into using the drug, as pet owners may prefer the nonsurgical option for various reasons—such as the pet's age and temperament, practical logistics, or owner aversion to anesthesia or surgery.

In addition, she discussed the Nu.Q Vet Cancer Test as a screening aid for early detection of some cancers such as lymphoma and hemangiosarcoma and Vetscan Imagyst for digital cytology.

But above all, Dr. Ettinger stressed the importance of supportive care for cancer patients, saying that in her experience, one of the top reasons pet owners stop chemotherapy is due to inappetence more than any other side effects.

"Sometimes the most important oncology drug isn’t chemotherapy," said Dr. Ettinger, urging veterinarians to be proactive about symptom management. "It's the supportive medications to keep them eating, to control their pain, and maintain quality of life."

The guidelines also feature a table covering supportive care options.

"Cancer sucks, but learning about cancer should not suck," Dr. Ettinger told the crowded room. "The guidelines help with that, because they make it easy, bite-sized, and manageable, but also, there's a lot of depth and detail in there. So be ready and be confident. Use the guidelines to help make a difference in patients and in practice."