A Guide to Modern Veterinary Care
In the world of veterinary medicine, cancer is not a dead end but a complex journey—and new guidelines are lighting the path forward.
When a beloved pet receives a cancer diagnosis, the world can seem to stop for their owner. What many don't realize is that veterinary medicine has transformed cancer in companion animals from an immediate death sentence to a manageable condition in many cases. With approximately 1 in 4 dogs developing neoplasia at some point in their lives, and cancer being the most common cause of death in dogs over one year old, this is not an uncommon reality for pet owners 1 7 .
The American Animal Hospital Association's (AAHA) 2016 Oncology Guidelines for Dogs and Cats represent a significant step forward in standardizing and improving cancer care for our pets. These guidelines provide veterinary professionals with a structured yet flexible approach to diagnosing and treating cancer, always with an emphasis on quality of life and the unique bond between pets and their families 1 2 .
Cancer management in pets has evolved dramatically from the days when options were limited. The 2016 AAHA Oncology Guidelines establish a systematic approach that ensures pets receive the best possible care regardless of whether they're treated by a primary care veterinarian or a specialist 5 .
What makes these guidelines particularly impactful is their recognition that each oncology case is medically unique. They recommend a patient-specific approach that includes accurate diagnosis, staging, therapeutic intervention, safety protocols for handling chemotherapy, appropriate referral when needed, and strong client support 1 2 .
This structured methodology matters because cancer is often a disease of older pets—a time when the human-animal bond is usually strongest. The emotional weight of a cancer diagnosis cannot be overstated, and the guidelines acknowledge this by emphasizing compassionate communication throughout the treatment process 1 .
Several factors have contributed to the growing importance of oncology in veterinary practice. Improvements in pet nutrition, widespread parasite control, regular vaccinations, and enhanced preventive care have collectively led to a growing population of older dogs and cats 1 .
Dogs included in a large-scale demographic study spanning two decades 1
Canine breeds where neoplastic disease was the most common terminal pathological process 1
This staggering statistic underscores why cancer management has become an essential component of comprehensive primary veterinary care.
The foundation of effective cancer management begins with precise diagnosis and staging. The AAHA Guidelines emphasize that determination of tumor type by histologic examination of a biopsy sample should form the basis for all subsequent steps in oncology case management 1 2 .
Diagnostic staging determines the extent of local disease and presence or absence of regional or distant metastasis. This process allows veterinarians to understand the full scope of the cancer and develop an appropriate treatment strategy 1 .
Modern veterinary oncology offers a multifaceted approach to cancer treatment. The choice of therapeutic modalities is based on tumor type, histologic grade, and stage, and may include:
This comprehensive approach allows veterinarians to tailor treatment plans to individual patients, considering the specific type of cancer, the pet's overall health, and the owner's treatment goals 1 2 .
The guidelines discuss strict safety precautions that should be observed in handling chemotherapy agents, which are now commonly used in veterinary oncology. These protocols protect not only the veterinary healthcare team but also the patient and pet owner 1 2 .
A recent retrospective study conducted at a Spanish Veterinary Teaching Hospital between 2015 and 2024 offers valuable insights into how cancer manifests and is treated in clinical practice 9 .
The study reviewed 123 animals (107 dogs and 16 cats) diagnosed with cancer, revealing an mean annual incidence risk of 530 per 100,000 animals attending the hospital. The breakdown by species showed 618 per 100,000 dogs and 264 per 100,000 cats 9 .
The research provided detailed information about the types and locations of tumors encountered, as well as how they were typically managed:
| Characteristic | Dogs (%) | Cats (%) | Overall (%) |
|---|---|---|---|
| Malignancy | |||
| Malignant | 87.8 | 87.8 | 87.8 |
| Benign | 12.2 | 12.2 | 12.2 |
| Histological Origin | |||
| Epithelial | 40.7 | 40.7 | 40.7 |
| Mesenchymal | 29.3 | 29.3 | 29.3 |
| Round Cells | 17.1 | 17.1 | 17.1 |
| Primary Location | |||
| Mammary Glands | 27.6 | 27.6 | 27.6 |
| Skin/Mucosa | 26.8 | 26.8 | 26.8 |
| Major Histological Types | |||
| Carcinoma | 35.8 | 35.8 | 35.8 |
| Lymphoma | 19.5 | 19.5 | 19.5 |
| Data adapted from the retrospective study of 123 animals at a Spanish Veterinary Teaching Hospital (2015-2024) 9 | |||
| Treatment Modality | Percentage of Animals |
|---|---|
| Surgery | 42.3% |
| Chemotherapy | 37.4% |
| Euthanasia | 26.8% |
| Chemotherapy Route | |
| Oral | Most common |
| Supportive Care | |
| Concomitant treatments | Frequently used |
| Dietary supplements | Frequently used |
| Data adapted from the retrospective study of 123 animals at a Spanish Veterinary Teaching Hospital (2015-2024) 9 | |
The demographic data from the study revealed that most animals with cancer were dogs (87.0%), females (62.6%), purebred (77.2%), and aged (78.9%) 9 . This aligns with the AAHA Guidelines' observation that cancer is often a disease of older pets 1 .
Modern veterinary oncology relies on a diverse array of diagnostic and therapeutic tools. The AAHA Guidelines highlight several crucial components:
| Tool/Resource | Function/Purpose |
|---|---|
| Histologic Examination | Gold standard for tumor type determination 1 |
| Diagnostic Staging | Determines extent of local disease and metastasis 1 |
| Safety Equipment | Protects team handling chemotherapeutic agents 1 |
| VCOG-CTCAE v2 | Standardized criteria for adverse events tracking 9 |
| Vet-ICD-O-canine | Standardized coding for canine neoplasms 9 |
| Supportive Medications | Manages symptoms and maintains quality of life 7 |
Since the publication of the 2016 guidelines, veterinary oncology has continued to advance at a remarkable pace. AAHA has announced that revamped oncology guidelines are coming in 2026, designed specifically to help general practitioners manage cancer cases in everyday practice 7 .
These updated guidelines will reflect a decade of progress in veterinary oncology and will address the growing challenge of accessing specialty cancer care due to cost limitations or insufficient numbers of veterinary oncologists 7 .
The 2026 guidelines are expected to highlight several "game-changing" novel cancer therapies that have emerged since 2016, including:
(tigilanol tiglate injection): Approved by the FDA in 2020 for treatment of dogs with nonmetastatic, cutaneous mast cell tumors 7
Newer therapeutic options showing promise 7
Recently approved treatments 7
Nu.Q Vet Cancer Test for early detection and Vetscan Imagyst for digital cytology 7
Dr. Sue Ettinger, a board-certified veterinary oncologist who helped preview the 2026 guidelines, emphasizes the importance of supportive care: "Sometimes the most important oncology drug isn't chemotherapy. It's the supportive medications to keep them eating, to control their pain, and maintain quality of life" 7 .
The 2016 AAHA Oncology Guidelines for Dogs and Cats represent a significant milestone in veterinary medicine, providing a structured yet flexible framework for managing cancer in companion animals. By emphasizing accurate diagnosis, appropriate staging, multimodal treatment, and compassionate communication, these guidelines have helped elevate the standard of care for pets with cancer.
As Dr. Jessica Vogelsang, AAHA's chief medical officer, notes regarding the upcoming 2026 guidelines, the goal is to help general practitioners identify what they can do to help pets with cancer, "so they feel more comfortable saying, 'I can help'" 7 .
For pet owners facing a cancer diagnosis for their dog or cat, today's veterinary medicine offers more options and hope than ever before. Through continued advances in detection and treatment, plus an unwavering commitment to quality of life, veterinarians are helping pets with cancer enjoy more good days with the families who love them.